v23.3.0-rc.1

otherwise it's rather hard to see them, at least in Firefox.

.eslintrc.js

@@ -1,6 +1,9 @@
 module.exports = {
     plugins: ["matrix-org", "import", "jsdoc"],
     extends: ["plugin:matrix-org/babel", "plugin:import/typescript"],
+    parserOptions: {
+        project: ["./tsconfig.json"],
+    },
     env: {
         browser: true,
         node: true,

.github/workflows/docs-pr-netlify.yaml

@@ -14,7 +14,7 @@ jobs:
             # There's a 'download artifact' action, but it hasn't been updated for the workflow_run action
             # (https://github.com/actions/download-artifact/issues/60) so instead we get this mess:
             - name: 📥 Download artifact
-              uses: dawidd6/action-download-artifact@e6e25ac3a2b93187502a8be1ef9e9603afc34925 # v2.24.2
+              uses: dawidd6/action-download-artifact@bd10f381a96414ce2b13a11bfa89902ba7cea07f # v2.24.3
               with:
                   workflow: static_analysis.yml
                   run_id: ${{ github.event.workflow_run.id }}

CHANGELOG.md

@@ -1,3 +1,46 @@
+Changes in [23.3.0-rc.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v23.3.0-rc.1) (2023-02-07)
+============================================================================================================
+
+## ✨ Features
+ * Element-R: implement encryption of outgoing events ([\#3122](https://github.com/matrix-org/matrix-js-sdk/pull/3122)).
+ * Poll model - page /relations results ([\#3073](https://github.com/matrix-org/matrix-js-sdk/pull/3073)). Contributed by @kerryarchibald.
+ * Poll model - validate end events ([\#3072](https://github.com/matrix-org/matrix-js-sdk/pull/3072)). Contributed by @kerryarchibald.
+ * Handle optional last_known_event_id property in m.predecessor ([\#3119](https://github.com/matrix-org/matrix-js-sdk/pull/3119)). Contributed by @andybalaam.
+ * Add support for stable identifier for fixed MAC in SAS verification ([\#3101](https://github.com/matrix-org/matrix-js-sdk/pull/3101)).
+ * Provide eventId as well as roomId from Room.findPredecessor ([\#3095](https://github.com/matrix-org/matrix-js-sdk/pull/3095)). Contributed by @andybalaam.
+ * MSC3946 Dynamic room predecessors ([\#3042](https://github.com/matrix-org/matrix-js-sdk/pull/3042)). Contributed by @andybalaam.
+ * Poll model ([\#3036](https://github.com/matrix-org/matrix-js-sdk/pull/3036)). Contributed by @kerryarchibald.
+ * Remove video tracks on video mute without renegotiating ([\#3091](https://github.com/matrix-org/matrix-js-sdk/pull/3091)).
+ * Introduces a backwards-compatible API change. `MegolmEncrypter#prepareToEncrypt`'s return type has changed from `void` to `() => void`. ([\#3035](https://github.com/matrix-org/matrix-js-sdk/pull/3035)). Contributed by @clarkf.
+
+## 🐛 Bug Fixes
+ * Element-R: fix a bug which prevented encryption working after a reload ([\#3126](https://github.com/matrix-org/matrix-js-sdk/pull/3126)).
+ * Element-R: Fix invite processing ([\#3121](https://github.com/matrix-org/matrix-js-sdk/pull/3121)).
+ * Don't throw with no `opponentDeviceInfo` ([\#3107](https://github.com/matrix-org/matrix-js-sdk/pull/3107)).
+ * Remove flaky megolm test ([\#3098](https://github.com/matrix-org/matrix-js-sdk/pull/3098)). Contributed by @clarkf.
+ * Fix "verifyLinks" functionality of getRoomUpgradeHistory ([\#3089](https://github.com/matrix-org/matrix-js-sdk/pull/3089)). Contributed by @andybalaam.
+
+Changes in [23.2.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v23.2.0) (2023-01-31)
+==================================================================================================
+
+## ✨ Features
+ * Implement decryption via the rust sdk ([\#3074](https://github.com/matrix-org/matrix-js-sdk/pull/3074)).
+ * Handle edits which are bundled with an event, per MSC3925 ([\#3045](https://github.com/matrix-org/matrix-js-sdk/pull/3045)).
+
+## 🐛 Bug Fixes
+ * Add null check for our own member event ([\#3082](https://github.com/matrix-org/matrix-js-sdk/pull/3082)).
+ * Handle group call getting initialised twice in quick succession ([\#3078](https://github.com/matrix-org/matrix-js-sdk/pull/3078)). Fixes vector-im/element-call#847.
+ * Correctly handle limited sync responses by resetting the thread timeline ([\#3056](https://github.com/matrix-org/matrix-js-sdk/pull/3056)). Fixes vector-im/element-web#23952. Contributed by @justjanne.
+ * Fix failure to start in firefox private browser ([\#3058](https://github.com/matrix-org/matrix-js-sdk/pull/3058)). Fixes vector-im/element-web#24216.
+ * Fix spurious "Decryption key withheld" messages ([\#3061](https://github.com/matrix-org/matrix-js-sdk/pull/3061)). Fixes vector-im/element-web#23803.
+ * Fix browser entrypoint ([\#3051](https://github.com/matrix-org/matrix-js-sdk/pull/3051)). Fixes #3013.
+
+Changes in [23.1.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v23.1.1) (2023-01-20)
+==================================================================================================
+
+## 🐛 Bug Fixes
+ * Fix backwards compability for environment not support Array.prototype.at ([\#3080](https://github.com/matrix-org/matrix-js-sdk/pull/3080)).
+
 Changes in [23.1.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v23.1.0) (2023-01-18)
 ==================================================================================================
 

package.json

@@ -1,6 +1,6 @@
 {
     "name": "matrix-js-sdk",
-    "version": "23.1.0",
+    "version": "23.3.0-rc.1",
     "description": "Matrix Client-Server SDK for Javascript",
     "engines": {
         "node": ">=16.0.0"
@@ -33,7 +33,7 @@
         "matrix-org"
     ],
     "main": "./lib/index.js",
-    "browser": "./lib/browser-index.js",
+    "browser": "./src/browser-index.ts",
     "matrix_src_main": "./src/index.ts",
     "matrix_src_browser": "./src/browser-index.ts",
     "matrix_lib_main": "./lib/index.js",
@@ -55,7 +55,7 @@
     ],
     "dependencies": {
         "@babel/runtime": "^7.12.5",
-        "@matrix-org/matrix-sdk-crypto-js": "^0.1.0-alpha.2",
+        "@matrix-org/matrix-sdk-crypto-js": "^0.1.0-alpha.3",
         "another-json": "^0.2.0",
         "bs58": "^5.0.0",
         "content-type": "^1.0.4",
@@ -88,7 +88,7 @@
         "@types/jest": "^29.0.0",
         "@types/node": "18",
         "@types/sdp-transform": "^2.4.5",
-        "@types/uuid": "7",
+        "@types/uuid": "9",
         "@typescript-eslint/eslint-plugin": "^5.45.0",
         "@typescript-eslint/parser": "^5.45.0",
         "allchange": "^1.0.6",
@@ -98,24 +98,25 @@
         "browserify": "^17.0.0",
         "docdash": "^2.0.0",
         "domexception": "^4.0.0",
-        "eslint": "8.29.0",
+        "eslint": "8.32.0",
         "eslint-config-google": "^0.14.0",
         "eslint-config-prettier": "^8.5.0",
         "eslint-import-resolver-typescript": "^3.5.1",
         "eslint-plugin-import": "^2.26.0",
         "eslint-plugin-jsdoc": "^39.6.4",
-        "eslint-plugin-matrix-org": "^0.9.0",
+        "eslint-plugin-matrix-org": "^0.10.0",
         "eslint-plugin-tsdoc": "^0.2.17",
         "eslint-plugin-unicorn": "^45.0.0",
         "exorcist": "^2.0.0",
         "fake-indexeddb": "^4.0.0",
+        "fetch-mock-jest": "^1.5.1",
         "jest": "^29.0.0",
         "jest-environment-jsdom": "^29.0.0",
         "jest-localstorage-mock": "^2.4.6",
         "jest-mock": "^29.0.0",
         "matrix-mock-request": "^2.5.0",
-        "prettier": "2.8.1",
-        "rimraf": "^3.0.2",
+        "prettier": "2.8.3",
+        "rimraf": "^4.0.0",
         "terser": "^5.5.1",
         "tsify": "^5.0.2",
         "typedoc": "^0.23.20",

spec/TestClient.ts

@@ -115,13 +115,12 @@ export class TestClient {
     }
 
     /**
-     * Set up expectations that the client will upload device keys.
+     * Set up expectations that the client will upload device keys (and possibly one-time keys)
      */
     public expectDeviceKeyUpload() {
         this.httpBackend
             .when("POST", "/keys/upload")
             .respond<IKeysUploadResponse, IUploadKeysRequest>(200, (_path, content) => {
-                expect(content.one_time_keys).toBe(undefined);
                 expect(content.device_keys).toBeTruthy();
 
                 logger.log(this + ": received device keys");
@@ -129,7 +128,17 @@ export class TestClient {
                 expect(Object.keys(this.oneTimeKeys!).length).toEqual(0);
 
                 this.deviceKeys = content.device_keys;
-                return { one_time_key_counts: { signed_curve25519: 0 } };
+
+                // the first batch of one-time keys may be uploaded at the same time.
+                if (content.one_time_keys) {
+                    logger.log(`${this}: received ${Object.keys(content.one_time_keys).length} one-time keys`);
+                    this.oneTimeKeys = content.one_time_keys;
+                }
+                return {
+                    one_time_key_counts: {
+                        signed_curve25519: Object.keys(this.oneTimeKeys!).length,
+                    },
+                };
             });
     }
 

spec/integ/crypto.spec.ts

@@ -1,6 +1,6 @@
 /*
 Copyright 2016 OpenMarket Ltd
-Copyright 2019-2022 The Matrix.org Foundation C.I.C.
+Copyright 2019-2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -17,6 +17,8 @@ limitations under the License.
 
 import anotherjson from "another-json";
 import MockHttpBackend from "matrix-mock-request";
+import "fake-indexeddb/auto";
+import { IDBFactory } from "fake-indexeddb";
 
 import * as testUtils from "../test-utils/test-utils";
 import { TestClient } from "../TestClient";
@@ -38,9 +40,17 @@ import {
 } from "../../src/matrix";
 import { IDeviceKeys } from "../../src/crypto/dehydration";
 import { DeviceInfo } from "../../src/crypto/deviceinfo";
+import { CRYPTO_BACKENDS, InitCrypto } from "../test-utils/test-utils";
 
 const ROOM_ID = "!room:id";
 
+afterEach(() => {
+    // reset fake-indexeddb after each test, to make sure we don't leak connections
+    // cf https://github.com/dumbmatter/fakeIndexedDB#wipingresetting-the-indexeddb-for-a-fresh-state
+    // eslint-disable-next-line no-global-assign
+    indexedDB = new IDBFactory();
+});
+
 // start an Olm session with a given recipient
 async function createOlmSession(olmAccount: Olm.Account, recipientTestClient: TestClient): Promise<Olm.Session> {
     const keys = await recipientTestClient.awaitOneTimeKeyUpload();
@@ -59,13 +69,21 @@ interface ToDeviceEvent {
     type: string;
 }
 
-// encrypt an event with olm
+/** encrypt an event with an existing olm session */
 function encryptOlmEvent(opts: {
+    /** the sender's user id */
     sender?: string;
+    /** the sender's curve25519 key */
     senderKey: string;
+    /** the sender's ed25519 key */
+    senderSigningKey: string;
+    /** the olm session to use for encryption */
     p2pSession: Olm.Session;
+    /** the recipient client */
     recipient: TestClient;
+    /** the payload of the message */
     plaincontent?: object;
+    /** the event type of the payload */
     plaintype?: string;
 }): ToDeviceEvent {
     expect(opts.senderKey).toBeTruthy();
@@ -78,6 +96,9 @@ function encryptOlmEvent(opts: {
         recipient_keys: {
             ed25519: opts.recipient.getSigningKey(),
         },
+        keys: {
+            ed25519: opts.senderSigningKey,
+        },
         sender: opts.sender || "@bob:xyz",
         type: opts.plaintype || "m.test",
     };
@@ -101,7 +122,7 @@ function encryptMegolmEvent(opts: {
     groupSession: Olm.OutboundGroupSession;
     plaintext?: Partial<IEvent>;
     room_id?: string;
-}): Pick<IEvent, "event_id" | "content" | "type"> {
+}): IEvent {
     expect(opts.senderKey).toBeTruthy();
     expect(opts.groupSession).toBeTruthy();
 
@@ -119,30 +140,44 @@ function encryptMegolmEvent(opts: {
         expect(opts.room_id).toBeTruthy();
         plaintext.room_id = opts.room_id;
     }
+    return encryptMegolmEventRawPlainText({ senderKey: opts.senderKey, groupSession: opts.groupSession, plaintext });
+}
 
+function encryptMegolmEventRawPlainText(opts: {
+    senderKey: string;
+    groupSession: Olm.OutboundGroupSession;
+    plaintext: Partial<IEvent>;
+}): IEvent {
     return {
-        event_id: "test_megolm_event_" + Math.random(),
+        event_id: "$test_megolm_event_" + Math.random(),
+        sender: "@not_the_real_sender:example.com",
+        origin_server_ts: 1672944778000,
         content: {
             algorithm: "m.megolm.v1.aes-sha2",
-            ciphertext: opts.groupSession.encrypt(JSON.stringify(plaintext)),
+            ciphertext: opts.groupSession.encrypt(JSON.stringify(opts.plaintext)),
             device_id: "testDevice",
             sender_key: opts.senderKey,
             session_id: opts.groupSession.session_id(),
         },
         type: "m.room.encrypted",
+        unsigned: {},
     };
 }
 
-// build an encrypted room_key event to share a group session
+/** build an encrypted room_key event to share a group session, using an existing olm session */
 function encryptGroupSessionKey(opts: {
-    senderKey: string;
     recipient: TestClient;
+    /** sender's olm account */
+    olmAccount: Olm.Account;
+    /** sender's olm session with the recipient */
     p2pSession: Olm.Session;
     groupSession: Olm.OutboundGroupSession;
     room_id?: string;
 }): Partial<IEvent> {
+    const senderKeys = JSON.parse(opts.olmAccount.identity_keys());
     return encryptOlmEvent({
-        senderKey: opts.senderKey,
+        senderKey: senderKeys.curve25519,
+        senderSigningKey: senderKeys.ed25519,
         recipient: opts.recipient,
         p2pSession: opts.p2pSession,
         plaincontent: {
@@ -219,6 +254,7 @@ async function establishOlmSession(testClient: TestClient, peerOlmAccount: Olm.A
     const p2pSession = await createOlmSession(peerOlmAccount, testClient);
     const olmEvent = encryptOlmEvent({
         senderKey: peerE2EKeys.curve25519,
+        senderSigningKey: peerE2EKeys.ed25519,
         recipient: testClient,
         p2pSession: p2pSession,
     });
@@ -315,11 +351,17 @@ async function expectSendMegolmMessage(
     return JSON.parse(r.plaintext);
 }
 
-describe("megolm", () => {
+describe.each(Object.entries(CRYPTO_BACKENDS))("megolm (%s)", (backend: string, initCrypto: InitCrypto) => {
     if (!global.Olm) {
+        // currently we use libolm to implement the crypto in the tests, so need it to be present.
         logger.warn("not running megolm tests: Olm not present");
         return;
     }
+
+    // oldBackendOnly is an alternative to `it` or `test` which will skip the test if we are running against the
+    // Rust backend. Once we have full support in the rust sdk, it will go away.
+    const oldBackendOnly = backend === "rust-sdk" ? test.skip : test;
+
     const Olm = global.Olm;
 
     let testOlmAccount = {} as unknown as Olm.Account;
@@ -384,29 +426,38 @@ describe("megolm", () => {
 
     beforeEach(async () => {
         aliceTestClient = new TestClient("@alice:localhost", "xzcvb", "akjgkrgjs");
-        await aliceTestClient.client.initCrypto();
+        await initCrypto(aliceTestClient.client);
 
+        // create a test olm device which we will use to communicate with alice. We use libolm to implement this.
+        await Olm.init();
         testOlmAccount = new Olm.Account();
         testOlmAccount.create();
         const testE2eKeys = JSON.parse(testOlmAccount.identity_keys());
         testSenderKey = testE2eKeys.curve25519;
     });
 
-    afterEach(() => aliceTestClient.stop());
+    afterEach(async () => {
+        await aliceTestClient.stop();
+    });
 
     it("Alice receives a megolm message", async () => {
         await aliceTestClient.start();
-        aliceTestClient.client.crypto!.deviceList.downloadKeys = () => Promise.resolve({});
+
+        // if we're using the old crypto impl, stub out some methods in the device manager.
+        // TODO: replace this with intercepts of the /keys/query endpoint to make it impl agnostic.
+        if (aliceTestClient.client.crypto) {
+            aliceTestClient.client.crypto.deviceList.downloadKeys = () => Promise.resolve({});
+            aliceTestClient.client.crypto.deviceList.getUserByIdentityKey = () => "@bob:xyz";
+        }
+
         const p2pSession = await createOlmSession(testOlmAccount, aliceTestClient);
         const groupSession = new Olm.OutboundGroupSession();
         groupSession.create();
 
-        aliceTestClient.client.crypto!.deviceList.getUserByIdentityKey = () => "@bob:xyz";
-
         // make the room_key event
         const roomKeyEncrypted = encryptGroupSessionKey({
-            senderKey: testSenderKey,
             recipient: aliceTestClient,
+            olmAccount: testOlmAccount,
             p2pSession: p2pSession,
             groupSession: groupSession,
             room_id: ROOM_ID,
@@ -444,20 +495,25 @@ describe("megolm", () => {
         expect(decryptedEvent.getContent().body).toEqual("42");
     });
 
-    it("Alice receives a megolm message before the session keys", async () => {
+    oldBackendOnly("Alice receives a megolm message before the session keys", async () => {
         // https://github.com/vector-im/element-web/issues/2273
         await aliceTestClient.start();
-        aliceTestClient.client.crypto!.deviceList.downloadKeys = () => Promise.resolve({});
+
+        // if we're using the old crypto impl, stub out some methods in the device manager.
+        // TODO: replace this with intercepts of the /keys/query endpoint to make it impl agnostic.
+        if (aliceTestClient.client.crypto) {
+            aliceTestClient.client.crypto.deviceList.downloadKeys = () => Promise.resolve({});
+            aliceTestClient.client.crypto.deviceList.getUserByIdentityKey = () => "@bob:xyz";
+        }
+
         const p2pSession = await createOlmSession(testOlmAccount, aliceTestClient);
         const groupSession = new Olm.OutboundGroupSession();
         groupSession.create();
 
-        aliceTestClient.client.crypto!.deviceList.getUserByIdentityKey = () => "@bob:xyz";
-
         // make the room_key event, but don't send it yet
         const roomKeyEncrypted = encryptGroupSessionKey({
-            senderKey: testSenderKey,
             recipient: aliceTestClient,
+            olmAccount: testOlmAccount,
             p2pSession: p2pSession,
             groupSession: groupSession,
             room_id: ROOM_ID,
@@ -507,17 +563,22 @@ describe("megolm", () => {
 
     it("Alice gets a second room_key message", async () => {
         await aliceTestClient.start();
-        aliceTestClient.client.crypto!.deviceList.downloadKeys = () => Promise.resolve({});
+
+        // if we're using the old crypto impl, stub out some methods in the device manager.
+        // TODO: replace this with intercepts of the /keys/query endpoint to make it impl agnostic.
+        if (aliceTestClient.client.crypto) {
+            aliceTestClient.client.crypto.deviceList.downloadKeys = () => Promise.resolve({});
+            aliceTestClient.client.crypto.deviceList.getUserByIdentityKey = () => "@bob:xyz";
+        }
+
         const p2pSession = await createOlmSession(testOlmAccount, aliceTestClient);
         const groupSession = new Olm.OutboundGroupSession();
         groupSession.create();
 
-        aliceTestClient.client.crypto!.deviceList.getUserByIdentityKey = () => "@bob:xyz";
-
         // make the room_key event
         const roomKeyEncrypted1 = encryptGroupSessionKey({
-            senderKey: testSenderKey,
             recipient: aliceTestClient,
+            olmAccount: testOlmAccount,
             p2pSession: p2pSession,
             groupSession: groupSession,
             room_id: ROOM_ID,
@@ -533,8 +594,8 @@ describe("megolm", () => {
         // make a second room_key event now that we have advanced the group
         // session.
         const roomKeyEncrypted2 = encryptGroupSessionKey({
-            senderKey: testSenderKey,
             recipient: aliceTestClient,
+            olmAccount: testOlmAccount,
             p2pSession: p2pSession,
             groupSession: groupSession,
             room_id: ROOM_ID,
@@ -572,7 +633,36 @@ describe("megolm", () => {
         expect(event.getContent().body).toEqual("42");
     });
 
-    it("Alice sends a megolm message", async () => {
+    oldBackendOnly("prepareToEncrypt", async () => {
+        aliceTestClient.expectKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
+        await aliceTestClient.start();
+        aliceTestClient.client.setGlobalErrorOnUnknownDevices(false);
+
+        // tell alice she is sharing a room with bob
+        aliceTestClient.httpBackend.when("GET", "/sync").respond(200, getSyncResponse(["@bob:xyz"]));
+        await aliceTestClient.flushSync();
+
+        // we expect alice first to query bob's keys...
+        aliceTestClient.httpBackend.when("POST", "/keys/query").respond(200, getTestKeysQueryResponse("@bob:xyz"));
+        aliceTestClient.httpBackend.flush("/keys/query", 1);
+
+        // ... and then claim one of his OTKs
+        aliceTestClient.httpBackend.when("POST", "/keys/claim").respond(200, getTestKeysClaimResponse("@bob:xyz"));
+        aliceTestClient.httpBackend.flush("/keys/claim", 1);
+
+        // fire off the prepare request
+        const room = aliceTestClient.client.getRoom(ROOM_ID);
+        expect(room).toBeTruthy();
+        const p = aliceTestClient.client.prepareToEncrypt(room!);
+
+        // we expect to get a room key message
+        await expectSendRoomKey(aliceTestClient.httpBackend, "@bob:xyz", testOlmAccount);
+
+        // the prepare request should complete successfully.
+        await p;
+    });
+
+    oldBackendOnly("Alice sends a megolm message", async () => {
         aliceTestClient.expectKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
         await aliceTestClient.start();
         const p2pSession = await establishOlmSession(aliceTestClient, testOlmAccount);
@@ -615,7 +705,7 @@ describe("megolm", () => {
         ]);
     });
 
-    it("We shouldn't attempt to send to blocked devices", async () => {
+    oldBackendOnly("We shouldn't attempt to send to blocked devices", async () => {
         aliceTestClient.expectKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
         await aliceTestClient.start();
         await establishOlmSession(aliceTestClient, testOlmAccount);
@@ -659,7 +749,7 @@ describe("megolm", () => {
             expect(() => aliceTestClient.client.getGlobalErrorOnUnknownDevices()).toThrowError("encryption disabled");
         });
 
-        it("should permit sending to unknown devices", async () => {
+        oldBackendOnly("should permit sending to unknown devices", async () => {
             expect(aliceTestClient.client.getGlobalErrorOnUnknownDevices()).toBeTruthy();
 
             aliceTestClient.expectKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
@@ -717,7 +807,7 @@ describe("megolm", () => {
             );
         });
 
-        it("should disable sending to unverified devices", async () => {
+        oldBackendOnly("should disable sending to unverified devices", async () => {
             aliceTestClient.expectKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
             await aliceTestClient.start();
             const p2pSession = await establishOlmSession(aliceTestClient, testOlmAccount);
@@ -775,7 +865,7 @@ describe("megolm", () => {
         });
     });
 
-    it("We should start a new megolm session when a device is blocked", async () => {
+    oldBackendOnly("We should start a new megolm session when a device is blocked", async () => {
         aliceTestClient.expectKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
         await aliceTestClient.start();
         const p2pSession = await establishOlmSession(aliceTestClient, testOlmAccount);
@@ -833,7 +923,7 @@ describe("megolm", () => {
     });
 
     // https://github.com/vector-im/element-web/issues/2676
-    it("Alice should send to her other devices", async () => {
+    oldBackendOnly("Alice should send to her other devices", async () => {
         // for this test, we make the testOlmAccount be another of Alice's devices.
         // it ought to get included in messages Alice sends.
         await aliceTestClient.start();
@@ -914,7 +1004,7 @@ describe("megolm", () => {
         expect(decrypted.content?.body).toEqual("test");
     });
 
-    it("Alice should wait for device list to complete when sending a megolm message", async () => {
+    oldBackendOnly("Alice should wait for device list to complete when sending a megolm message", async () => {
         aliceTestClient.expectKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
         await aliceTestClient.start();
         await establishOlmSession(aliceTestClient, testOlmAccount);
@@ -944,22 +1034,27 @@ describe("megolm", () => {
         await Promise.all([downloadPromise, sendPromise]);
     });
 
-    it("Alice exports megolm keys and imports them to a new device", async () => {
+    oldBackendOnly("Alice exports megolm keys and imports them to a new device", async () => {
         aliceTestClient.expectKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
         await aliceTestClient.start();
-        aliceTestClient.client.crypto!.deviceList.downloadKeys = () => Promise.resolve({});
+
+        // if we're using the old crypto impl, stub out some methods in the device manager.
+        // TODO: replace this with intercepts of the /keys/query endpoint to make it impl agnostic.
+        if (aliceTestClient.client.crypto) {
+            aliceTestClient.client.crypto.deviceList.downloadKeys = () => Promise.resolve({});
+            aliceTestClient.client.crypto.deviceList.getUserByIdentityKey = () => "@bob:xyz";
+        }
+
         // establish an olm session with alice
         const p2pSession = await createOlmSession(testOlmAccount, aliceTestClient);
 
-        aliceTestClient.client.crypto!.deviceList.getUserByIdentityKey = () => "@bob:xyz";
-
         const groupSession = new Olm.OutboundGroupSession();
         groupSession.create();
 
         // make the room_key event
         const roomKeyEncrypted = encryptGroupSessionKey({
-            senderKey: testSenderKey,
             recipient: aliceTestClient,
+            olmAccount: testOlmAccount,
             p2pSession: p2pSession,
             groupSession: groupSession,
             room_id: ROOM_ID,
@@ -999,11 +1094,15 @@ describe("megolm", () => {
         aliceTestClient.stop();
 
         aliceTestClient = new TestClient("@alice:localhost", "device2", "access_token2");
-        await aliceTestClient.client.initCrypto();
+        await initCrypto(aliceTestClient.client);
         await aliceTestClient.client.importRoomKeys(exported);
         await aliceTestClient.start();
 
-        aliceTestClient.client.crypto!.deviceList.getUserByIdentityKey = () => "@bob:xyz";
+        // if we're using the old crypto impl, stub out some methods in the device manager.
+        // TODO: replace this with intercepts of the /keys/query endpoint to make it impl agnostic.
+        if (aliceTestClient.client.crypto) {
+            aliceTestClient.client.crypto.deviceList.getUserByIdentityKey = () => "@bob:xyz";
+        }
 
         const syncResponse = {
             next_batch: 1,
@@ -1079,17 +1178,22 @@ describe("megolm", () => {
 
     it("Alice can decrypt a message with falsey content", async () => {
         await aliceTestClient.start();
-        aliceTestClient.client.crypto!.deviceList.downloadKeys = () => Promise.resolve({});
+
+        // if we're using the old crypto impl, stub out some methods in the device manager.
+        // TODO: replace this with intercepts of the /keys/query endpoint to make it impl agnostic.
+        if (aliceTestClient.client.crypto) {
+            aliceTestClient.client.crypto.deviceList.downloadKeys = () => Promise.resolve({});
+            aliceTestClient.client.crypto.deviceList.getUserByIdentityKey = () => "@bob:xyz";
+        }
+
         const p2pSession = await createOlmSession(testOlmAccount, aliceTestClient);
         const groupSession = new Olm.OutboundGroupSession();
         groupSession.create();
 
-        aliceTestClient.client.crypto!.deviceList.getUserByIdentityKey = () => "@bob:xyz";
-
         // make the room_key event
         const roomKeyEncrypted = encryptGroupSessionKey({
-            senderKey: testSenderKey,
             recipient: aliceTestClient,
+            olmAccount: testOlmAccount,
             p2pSession: p2pSession,
             groupSession: groupSession,
             room_id: ROOM_ID,
@@ -1101,17 +1205,11 @@ describe("megolm", () => {
             room_id: ROOM_ID,
         };
 
-        const messageEncrypted = {
-            event_id: "test_megolm_event",
-            content: {
-                algorithm: "m.megolm.v1.aes-sha2",
-                ciphertext: groupSession.encrypt(JSON.stringify(plaintext)),
-                device_id: "testDevice",
-                sender_key: testSenderKey,
-                session_id: groupSession.session_id(),
-            },
-            type: "m.room.encrypted",
-        };
+        const messageEncrypted = encryptMegolmEventRawPlainText({
+            senderKey: testSenderKey,
+            groupSession: groupSession,
+            plaintext: plaintext,
+        });
 
         // Alice gets both the events in a single sync
         const syncResponse = {
@@ -1138,79 +1236,21 @@ describe("megolm", () => {
         expect(decryptedEvent.getClearContent()).toBeUndefined();
     });
 
-    it("should successfully decrypt bundled redaction events that don't include a room_id in their /sync data", async () => {
-        await aliceTestClient.start();
-        aliceTestClient.client.crypto!.deviceList.downloadKeys = () => Promise.resolve({});
-        const p2pSession = await createOlmSession(testOlmAccount, aliceTestClient);
-        const groupSession = new Olm.OutboundGroupSession();
-        groupSession.create();
-
-        aliceTestClient.client.crypto!.deviceList.getUserByIdentityKey = () => "@bob:xyz";
-
-        // make the room_key event
-        const roomKeyEncrypted = encryptGroupSessionKey({
-            senderKey: testSenderKey,
-            recipient: aliceTestClient,
-            p2pSession: p2pSession,
-            groupSession: groupSession,
-            room_id: ROOM_ID,
-        });
-
-        // encrypt a message with the group session
-        const messageEncrypted = encryptMegolmEvent({
-            senderKey: testSenderKey,
-            groupSession: groupSession,
-            room_id: ROOM_ID,
-        });
-
-        const redactionEncrypted = encryptMegolmEvent({
-            senderKey: testSenderKey,
-            groupSession: groupSession,
-            plaintext: {
-                room_id: ROOM_ID,
-                type: "m.room.redaction",
-                redacts: messageEncrypted.event_id,
-                content: { reason: "redaction test" },
-            },
-        });
-
-        const messageEncryptedWithRedaction = {
-            ...messageEncrypted,
-            unsigned: { redacted_because: redactionEncrypted },
-        };
-
-        const syncResponse = {
-            next_batch: 1,
-            to_device: {
-                events: [roomKeyEncrypted],
-            },
-            rooms: {
-                join: {
-                    [ROOM_ID]: { timeline: { events: [messageEncryptedWithRedaction] } },
-                },
-            },
-        };
-
-        aliceTestClient.httpBackend.when("GET", "/sync").respond(200, syncResponse);
-        await aliceTestClient.flushSync();
-
-        const room = aliceTestClient.client.getRoom(ROOM_ID)!;
-        const event = room.getLiveTimeline().getEvents()[0];
-        expect(event.isEncrypted()).toBe(true);
-        await event.attemptDecryption(aliceTestClient.client.crypto!);
-        expect(event.getContent()).toEqual({});
-        const redactionEvent: any = event.getRedactionEvent();
-        expect(redactionEvent.content.reason).toEqual("redaction test");
-    });
-
-    it("Alice receives shared history before being invited to a room by the sharer", async () => {
+    oldBackendOnly("Alice receives shared history before being invited to a room by the sharer", async () => {
         const beccaTestClient = new TestClient("@becca:localhost", "foobar", "bazquux");
         await beccaTestClient.client.initCrypto();
 
         await aliceTestClient.start();
-        aliceTestClient.client.crypto!.deviceList.downloadKeys = () => Promise.resolve({});
         await beccaTestClient.start();
 
+        // if we're using the old crypto impl, stub out some methods in the device manager.
+        // TODO: replace this with intercepts of the /keys/query endpoint to make it impl agnostic.
+        if (aliceTestClient.client.crypto) {
+            aliceTestClient.client.crypto!.deviceList.downloadKeys = () => Promise.resolve({});
+            aliceTestClient.client.crypto!.deviceList.getDeviceByIdentityKey = () => device;
+            aliceTestClient.client.crypto!.deviceList.getUserByIdentityKey = () => beccaTestClient.client.getUserId()!;
+        }
+
         const beccaRoom = new Room(ROOM_ID, beccaTestClient.client, "@becca:localhost", {});
         beccaTestClient.client.store.storeRoom(beccaRoom);
         await beccaTestClient.client.setRoomEncryption(ROOM_ID, { algorithm: "m.megolm.v1.aes-sha2" });
@@ -1236,8 +1276,6 @@ describe("megolm", () => {
         event.claimedEd25519Key = null;
 
         const device = new DeviceInfo(beccaTestClient.client.deviceId!);
-        aliceTestClient.client.crypto!.deviceList.getDeviceByIdentityKey = () => device;
-        aliceTestClient.client.crypto!.deviceList.getUserByIdentityKey = () => beccaTestClient.client.getUserId()!;
 
         // Create an olm session for Becca and Alice's devices
         const aliceOtks = await aliceTestClient.awaitOneTimeKeyUpload();
@@ -1268,6 +1306,7 @@ describe("megolm", () => {
         );
         const encryptedForwardedKey = encryptOlmEvent({
             sender: "@becca:localhost",
+            senderSigningKey: beccaTestClient.getSigningKey(),
             senderKey: beccaTestClient.getDeviceKey(),
             recipient: aliceTestClient,
             p2pSession: p2pSession,
@@ -1349,7 +1388,7 @@ describe("megolm", () => {
         await beccaTestClient.stop();
     });
 
-    it("Alice receives shared history before being invited to a room by someone else", async () => {
+    oldBackendOnly("Alice receives shared history before being invited to a room by someone else", async () => {
         const beccaTestClient = new TestClient("@becca:localhost", "foobar", "bazquux");
         await beccaTestClient.client.initCrypto();
 
@@ -1413,6 +1452,7 @@ describe("megolm", () => {
         const encryptedForwardedKey = encryptOlmEvent({
             sender: "@becca:localhost",
             senderKey: beccaTestClient.getDeviceKey(),
+            senderSigningKey: beccaTestClient.getSigningKey(),
             recipient: aliceTestClient,
             p2pSession: p2pSession,
             plaincontent: {
@@ -1494,7 +1534,7 @@ describe("megolm", () => {
         await beccaTestClient.stop();
     });
 
-    it("allows sending an encrypted event as soon as room state arrives", async () => {
+    oldBackendOnly("allows sending an encrypted event as soon as room state arrives", async () => {
         /* Empirically, clients expect to be able to send encrypted events as soon as the
          * RoomStateEvent.NewMember notification is emitted, so test that works correctly.
          */
@@ -1619,7 +1659,7 @@ describe("megolm", () => {
             await aliceTestClient.httpBackend.flush(membersPath, 1);
         }
 
-        it("Sending an event initiates a member list sync", async () => {
+        oldBackendOnly("Sending an event initiates a member list sync", async () => {
             // we expect a call to the /members list...
             const memberListPromise = expectMembershipRequest(ROOM_ID, ["@bob:xyz"]);
 
@@ -1651,7 +1691,7 @@ describe("megolm", () => {
             ]);
         });
 
-        it("loading the membership list inhibits a later load", async () => {
+        oldBackendOnly("loading the membership list inhibits a later load", async () => {
             const room = aliceTestClient.client.getRoom(ROOM_ID)!;
             await Promise.all([room.loadMembersIfNeeded(), expectMembershipRequest(ROOM_ID, ["@bob:xyz"])]);
 
@@ -1678,4 +1718,79 @@ describe("megolm", () => {
             await Promise.all([sendPromise, megolmMessagePromise, aliceTestClient.httpBackend.flush("/keys/query", 1)]);
         });
     });
+
+    describe("m.room_key.withheld handling", () => {
+        // TODO: there are a bunch more tests for this sort of thing in spec/unit/crypto/algorithms/megolm.spec.ts.
+        //   They should be converted to integ tests and moved.
+
+        oldBackendOnly("does not block decryption on an 'm.unavailable' report", async function () {
+            await aliceTestClient.start();
+
+            // there may be a key downloads for alice
+            aliceTestClient.httpBackend.when("POST", "/keys/query").respond(200, {});
+            aliceTestClient.httpBackend.flush("/keys/query", 1, 5000);
+
+            // encrypt a message with a group session.
+            const groupSession = new Olm.OutboundGroupSession();
+            groupSession.create();
+            const messageEncryptedEvent = encryptMegolmEvent({
+                senderKey: testSenderKey,
+                groupSession: groupSession,
+                room_id: ROOM_ID,
+            });
+
+            // Alice gets the room message, but not the key
+            aliceTestClient.httpBackend.when("GET", "/sync").respond(200, {
+                next_batch: 1,
+                rooms: {
+                    join: { [ROOM_ID]: { timeline: { events: [messageEncryptedEvent] } } },
+                },
+            });
+            await aliceTestClient.flushSync();
+
+            // alice will (eventually) send a room-key request
+            aliceTestClient.httpBackend.when("PUT", "/sendToDevice/m.room_key_request/").respond(200, {});
+            await aliceTestClient.httpBackend.flush("/sendToDevice/m.room_key_request/", 1, 1000);
+
+            // at this point, the message should be a decryption failure
+            const room = aliceTestClient.client.getRoom(ROOM_ID)!;
+            const event = room.getLiveTimeline().getEvents()[0];
+            expect(event.isDecryptionFailure()).toBeTruthy();
+
+            // we want to wait for the message to be updated, so create a promise for it
+            const retryPromise = new Promise((resolve) => {
+                event.once(MatrixEventEvent.Decrypted, (ev) => {
+                    resolve(ev);
+                });
+            });
+
+            // alice gets back a room-key-withheld notification
+            aliceTestClient.httpBackend.when("GET", "/sync").respond(200, {
+                next_batch: 2,
+                to_device: {
+                    events: [
+                        {
+                            type: "m.room_key.withheld",
+                            sender: "@bob:example.com",
+                            content: {
+                                algorithm: "m.megolm.v1.aes-sha2",
+                                room_id: ROOM_ID,
+                                session_id: groupSession.session_id(),
+                                sender_key: testSenderKey,
+                                code: "m.unavailable",
+                                reason: "",
+                            },
+                        },
+                    ],
+                },
+            });
+            await aliceTestClient.flushSync();
+
+            // the withheld notification should trigger a retry; wait for it
+            await retryPromise;
+
+            // finally: the message should still be a regular decryption failure, not a withheld notification.
+            expect(event.getContent().body).not.toContain("withheld");
+        });
+    });
 });

spec/integ/matrix-client-event-timeline.spec.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2022 The Matrix.org Foundation C.I.C.
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -590,7 +590,7 @@ describe("MatrixClient event timelines", function () {
 
         it("should handle thread replies with server support by fetching a contiguous thread timeline", async () => {
             // @ts-ignore
-            client.clientOpts.experimentalThreadSupport = true;
+            client.clientOpts.threadSupport = true;
             Thread.setServerSideSupport(FeatureSupport.Experimental);
             await client.stopClient(); // we don't need the client to be syncing at this time
             const room = client.getRoom(roomId)!;
@@ -647,7 +647,7 @@ describe("MatrixClient event timelines", function () {
 
         it("should return relevant timeline from non-thread timelineSet when asking for the thread root", async () => {
             // @ts-ignore
-            client.clientOpts.experimentalThreadSupport = true;
+            client.clientOpts.threadSupport = true;
             Thread.setServerSideSupport(FeatureSupport.Experimental);
             client.stopClient(); // we don't need the client to be syncing at this time
             const room = client.getRoom(roomId)!;
@@ -680,7 +680,7 @@ describe("MatrixClient event timelines", function () {
 
         it("should return undefined when event is not in the thread that the given timelineSet is representing", () => {
             // @ts-ignore
-            client.clientOpts.experimentalThreadSupport = true;
+            client.clientOpts.threadSupport = true;
             Thread.setServerSideSupport(FeatureSupport.Experimental);
             client.stopClient(); // we don't need the client to be syncing at this time
             const room = client.getRoom(roomId)!;
@@ -709,7 +709,7 @@ describe("MatrixClient event timelines", function () {
 
         it("should return undefined when event is within a thread but timelineSet is not", () => {
             // @ts-ignore
-            client.clientOpts.experimentalThreadSupport = true;
+            client.clientOpts.threadSupport = true;
             Thread.setServerSideSupport(FeatureSupport.Experimental);
             client.stopClient(); // we don't need the client to be syncing at this time
             const room = client.getRoom(roomId)!;
@@ -1127,7 +1127,7 @@ describe("MatrixClient event timelines", function () {
         };
 
         // @ts-ignore
-        client.clientOpts.experimentalThreadSupport = true;
+        client.clientOpts.threadSupport = true;
         Thread.setServerSideSupport(FeatureSupport.Stable);
         Thread.setServerSideListSupport(FeatureSupport.Stable);
         Thread.setServerSideFwdPaginationSupport(FeatureSupport.Stable);
@@ -1263,7 +1263,7 @@ describe("MatrixClient event timelines", function () {
         describe("with server compatibility", function () {
             beforeEach(() => {
                 // @ts-ignore
-                client.clientOpts.experimentalThreadSupport = true;
+                client.clientOpts.threadSupport = true;
                 Thread.setServerSideSupport(FeatureSupport.Stable);
                 Thread.setServerSideListSupport(FeatureSupport.Stable);
                 Thread.setServerSideFwdPaginationSupport(FeatureSupport.Stable);
@@ -1421,7 +1421,7 @@ describe("MatrixClient event timelines", function () {
                 };
 
                 // @ts-ignore
-                client.clientOpts.experimentalThreadSupport = true;
+                client.clientOpts.threadSupport = true;
                 Thread.setServerSideSupport(FeatureSupport.Stable);
                 Thread.setServerSideListSupport(FeatureSupport.Stable);
                 Thread.setServerSideFwdPaginationSupport(FeatureSupport.Stable);
@@ -1473,7 +1473,7 @@ describe("MatrixClient event timelines", function () {
         describe("without server compatibility", function () {
             beforeEach(() => {
                 // @ts-ignore
-                client.clientOpts.experimentalThreadSupport = true;
+                client.clientOpts.threadSupport = true;
                 Thread.setServerSideSupport(FeatureSupport.Experimental);
                 Thread.setServerSideListSupport(FeatureSupport.None);
             });
@@ -1539,7 +1539,7 @@ describe("MatrixClient event timelines", function () {
 
         it("should add lazy loading filter", async () => {
             // @ts-ignore
-            client.clientOpts.experimentalThreadSupport = true;
+            client.clientOpts.threadSupport = true;
             Thread.setServerSideSupport(FeatureSupport.Experimental);
             Thread.setServerSideListSupport(FeatureSupport.Stable);
             // @ts-ignore
@@ -1567,7 +1567,7 @@ describe("MatrixClient event timelines", function () {
 
         it("should correctly pass pagination token", async () => {
             // @ts-ignore
-            client.clientOpts.experimentalThreadSupport = true;
+            client.clientOpts.threadSupport = true;
             Thread.setServerSideSupport(FeatureSupport.Experimental);
             Thread.setServerSideListSupport(FeatureSupport.Stable);
 
@@ -1892,7 +1892,7 @@ describe("MatrixClient event timelines", function () {
 
         it("in stable mode", async () => {
             // @ts-ignore
-            client.clientOpts.experimentalThreadSupport = true;
+            client.clientOpts.threadSupport = true;
             Thread.setServerSideSupport(FeatureSupport.Stable);
             Thread.setServerSideListSupport(FeatureSupport.Stable);
             Thread.setServerSideFwdPaginationSupport(FeatureSupport.Stable);
@@ -1902,7 +1902,7 @@ describe("MatrixClient event timelines", function () {
 
         it("in backwards compatible unstable mode", async () => {
             // @ts-ignore
-            client.clientOpts.experimentalThreadSupport = true;
+            client.clientOpts.threadSupport = true;
             Thread.setServerSideSupport(FeatureSupport.Experimental);
             Thread.setServerSideListSupport(FeatureSupport.Experimental);
             Thread.setServerSideFwdPaginationSupport(FeatureSupport.Experimental);
@@ -1912,7 +1912,7 @@ describe("MatrixClient event timelines", function () {
 
         it("in backwards compatible mode", async () => {
             // @ts-ignore
-            client.clientOpts.experimentalThreadSupport = true;
+            client.clientOpts.threadSupport = true;
             Thread.setServerSideSupport(FeatureSupport.Experimental);
             Thread.setServerSideListSupport(FeatureSupport.None);
             Thread.setServerSideFwdPaginationSupport(FeatureSupport.None);

spec/integ/matrix-client-methods.spec.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2022 The Matrix.org Foundation C.I.C.
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -35,7 +35,7 @@ describe("MatrixClient", function () {
     let store: MemoryStore | undefined;
 
     const defaultClientOpts: IStoredClientOpts = {
-        experimentalThreadSupport: false,
+        threadSupport: false,
     };
     const setupTests = (): [MatrixClient, HttpBackend, MemoryStore] => {
         const store = new MemoryStore();
@@ -671,7 +671,7 @@ describe("MatrixClient", function () {
             // @ts-ignore setting private property
             client!.clientOpts = {
                 ...defaultClientOpts,
-                experimentalThreadSupport: true,
+                threadSupport: true,
             };
 
             const eventPollResponseReference = buildEventPollResponseReference();
@@ -702,7 +702,7 @@ describe("MatrixClient", function () {
             // @ts-ignore setting private property
             client!.clientOpts = {
                 ...defaultClientOpts,
-                experimentalThreadSupport: true,
+                threadSupport: true,
             };
 
             const eventPollStartThreadRoot = buildEventPollStartThreadRoot();
@@ -726,7 +726,7 @@ describe("MatrixClient", function () {
             // @ts-ignore setting private property
             client!.clientOpts = {
                 ...defaultClientOpts,
-                experimentalThreadSupport: true,
+                threadSupport: true,
             };
 
             const eventPollResponseReference = buildEventPollResponseReference();
@@ -750,7 +750,7 @@ describe("MatrixClient", function () {
             // @ts-ignore setting private property
             client!.clientOpts = {
                 ...defaultClientOpts,
-                experimentalThreadSupport: true,
+                threadSupport: true,
             };
 
             const eventPollStartThreadRoot = buildEventPollStartThreadRoot();
@@ -774,7 +774,7 @@ describe("MatrixClient", function () {
             // @ts-ignore setting private property
             client!.clientOpts = {
                 ...defaultClientOpts,
-                experimentalThreadSupport: true,
+                threadSupport: true,
             };
             // This is based on recording the events in a real room:
 
@@ -831,7 +831,7 @@ describe("MatrixClient", function () {
             // @ts-ignore setting private property
             client!.clientOpts = {
                 ...defaultClientOpts,
-                experimentalThreadSupport: true,
+                threadSupport: true,
             };
 
             const threadRootEvent = buildEventPollStartThreadRoot();
@@ -857,7 +857,7 @@ describe("MatrixClient", function () {
             // @ts-ignore setting private property
             client!.clientOpts = {
                 ...defaultClientOpts,
-                experimentalThreadSupport: true,
+                threadSupport: true,
             };
 
             const threadRootEvent = buildEventPollStartThreadRoot();
@@ -878,7 +878,7 @@ describe("MatrixClient", function () {
             // @ts-ignore setting private property
             client!.clientOpts = {
                 ...defaultClientOpts,
-                experimentalThreadSupport: true,
+                threadSupport: true,
             };
 
             const threadRootEvent = buildEventPollStartThreadRoot();

spec/integ/olm-encryption-spec.ts

@@ -22,7 +22,7 @@ limitations under the License.
  *
  * Note that megolm (group) conversation is not tested here.
  *
- * See also `megolm.spec.js`.
+ * See also `crypto.spec.js`.
  */
 
 // load olm before the sdk if possible

spec/integ/sliding-sync-sdk.spec.ts

@@ -52,10 +52,9 @@ describe("SlidingSyncSdk", () => {
     const selfAccessToken = "aseukfgwef";
 
     const mockifySlidingSync = (s: SlidingSync): SlidingSync => {
-        s.getList = jest.fn();
+        s.getListParams = jest.fn();
         s.getListData = jest.fn();
         s.getRoomSubscriptions = jest.fn();
-        s.listLength = jest.fn();
         s.modifyRoomSubscriptionInfo = jest.fn();
         s.modifyRoomSubscriptions = jest.fn();
         s.registerExtension = jest.fn();
@@ -115,7 +114,7 @@ describe("SlidingSyncSdk", () => {
         const testClient = new TestClient(selfUserId, "DEVICE", selfAccessToken);
         httpBackend = testClient.httpBackend;
         client = testClient.client;
-        mockSlidingSync = mockifySlidingSync(new SlidingSync("", [], {}, client, 0));
+        mockSlidingSync = mockifySlidingSync(new SlidingSync("", new Map(), {}, client, 0));
         if (testOpts.withCrypto) {
             httpBackend!.when("GET", "/room_keys/version").respond(404, {});
             await client!.initCrypto();
@@ -549,7 +548,7 @@ describe("SlidingSyncSdk", () => {
         it("emits SyncState.Reconnecting when < FAILED_SYNC_ERROR_THRESHOLD & SyncState.Error when over", async () => {
             mockSlidingSync!.emit(SlidingSyncEvent.Lifecycle, SlidingSyncState.Complete, {
                 pos: "h",
-                lists: [],
+                lists: {},
                 rooms: {},
                 extensions: {},
             });
@@ -577,7 +576,7 @@ describe("SlidingSyncSdk", () => {
         it("emits SyncState.Syncing after a previous SyncState.Error", async () => {
             mockSlidingSync!.emit(SlidingSyncEvent.Lifecycle, SlidingSyncState.Complete, {
                 pos: "i",
-                lists: [],
+                lists: {},
                 rooms: {},
                 extensions: {},
             });

spec/integ/sliding-sync.spec.ts

@@ -64,10 +64,10 @@ describe("SlidingSync", () => {
         let slidingSync: SlidingSync;
 
         it("should start the sync loop upon calling start()", async () => {
-            slidingSync = new SlidingSync(proxyBaseUrl, [], {}, client!, 1);
+            slidingSync = new SlidingSync(proxyBaseUrl, new Map(), {}, client!, 1);
             const fakeResp = {
                 pos: "a",
-                lists: [],
+                lists: {},
                 rooms: {},
                 extensions: {},
             };
@@ -90,7 +90,7 @@ describe("SlidingSync", () => {
 
         it("should reset the connection on HTTP 400 and send everything again", async () => {
             // seed the connection with some lists, extensions and subscriptions to verify they are sent again
-            slidingSync = new SlidingSync(proxyBaseUrl, [], {}, client!, 1);
+            slidingSync = new SlidingSync(proxyBaseUrl, new Map(), {}, client!, 1);
             const roomId = "!sub:localhost";
             const subInfo = {
                 timeline_limit: 42,
@@ -114,7 +114,7 @@ describe("SlidingSync", () => {
             };
             slidingSync.modifyRoomSubscriptions(new Set([roomId]));
             slidingSync.modifyRoomSubscriptionInfo(subInfo);
-            slidingSync.setList(0, listInfo);
+            slidingSync.setList("a", listInfo);
             slidingSync.registerExtension(ext);
             slidingSync.start();
 
@@ -128,7 +128,7 @@ describe("SlidingSync", () => {
                     expect(body.room_subscriptions).toEqual({
                         [roomId]: subInfo,
                     });
-                    expect(body.lists[0]).toEqual(listInfo);
+                    expect(body.lists["a"]).toEqual(listInfo);
                     expect(body.extensions).toBeTruthy();
                     expect(body.extensions["custom_extension"]).toEqual({ initial: true });
                     expect(req.queryParams!["pos"]).toBeUndefined();
@@ -137,7 +137,7 @@ describe("SlidingSync", () => {
                 .respond(200, function () {
                     return {
                         pos: "11",
-                        lists: [{ count: 5 }],
+                        lists: { a: { count: 5 } },
                         extensions: {},
                         txn_id: txnId,
                     };
@@ -151,7 +151,7 @@ describe("SlidingSync", () => {
                     const body = req.data;
                     logger.debug("got ", body);
                     expect(body.room_subscriptions).toBeFalsy();
-                    expect(body.lists[0]).toEqual({
+                    expect(body.lists["a"]).toEqual({
                         ranges: [[0, 10]],
                     });
                     expect(body.extensions).toBeTruthy();
@@ -161,7 +161,7 @@ describe("SlidingSync", () => {
                 .respond(200, function () {
                     return {
                         pos: "12",
-                        lists: [{ count: 5 }],
+                        lists: { a: { count: 5 } },
                         extensions: {},
                     };
                 });
@@ -185,7 +185,7 @@ describe("SlidingSync", () => {
                     expect(body.room_subscriptions).toEqual({
                         [roomId]: subInfo,
                     });
-                    expect(body.lists[0]).toEqual(listInfo);
+                    expect(body.lists["a"]).toEqual(listInfo);
                     expect(body.extensions).toBeTruthy();
                     expect(body.extensions["custom_extension"]).toEqual({ initial: true });
                     expect(req.queryParams!["pos"]).toBeUndefined();
@@ -193,7 +193,7 @@ describe("SlidingSync", () => {
                 .respond(200, function () {
                     return {
                         pos: "1",
-                        lists: [{ count: 6 }],
+                        lists: { a: { count: 6 } },
                         extensions: {},
                     };
                 });
@@ -221,7 +221,7 @@ describe("SlidingSync", () => {
 
         it("should be able to subscribe to a room", async () => {
             // add the subscription
-            slidingSync = new SlidingSync(proxyBaseUrl, [], roomSubInfo, client!, 1);
+            slidingSync = new SlidingSync(proxyBaseUrl, new Map(), roomSubInfo, client!, 1);
             slidingSync.modifyRoomSubscriptions(new Set([roomId]));
             httpBackend!
                 .when("POST", syncUrl)
@@ -233,7 +233,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "a",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {
                         [roomId]: wantRoomData,
@@ -266,7 +266,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "a",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {
                         [roomId]: wantRoomData,
@@ -313,7 +313,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {
                         [anotherRoomID]: anotherRoomData,
@@ -344,7 +344,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                 });
 
             const p = listenUntil(slidingSync, "SlidingSync.Lifecycle", (state) => {
@@ -402,19 +402,19 @@ describe("SlidingSync", () => {
                     is_dm: true,
                 },
             };
-            slidingSync = new SlidingSync(proxyBaseUrl, [listReq], {}, client!, 1);
+            slidingSync = new SlidingSync(proxyBaseUrl, new Map([["a", listReq]]), {}, client!, 1);
             httpBackend!
                 .when("POST", syncUrl)
                 .check(function (req) {
                     const body = req.data;
                     logger.log("list", body);
                     expect(body.lists).toBeTruthy();
-                    expect(body.lists[0]).toEqual(listReq);
+                    expect(body.lists["a"]).toEqual(listReq);
                 })
                 .respond(200, {
                     pos: "a",
-                    lists: [
-                        {
+                    lists: {
+                        a: {
                             count: 500,
                             ops: [
                                 {
@@ -424,7 +424,7 @@ describe("SlidingSync", () => {
                                 },
                             ],
                         },
-                    ],
+                    },
                     rooms: rooms,
                 });
             const listenerData: Record<string, MSC3575RoomData> = {};
@@ -444,15 +444,14 @@ describe("SlidingSync", () => {
             expect(listenerData[roomB]).toEqual(rooms[roomB]);
             expect(listenerData[roomC]).toEqual(rooms[roomC]);
 
-            expect(slidingSync.listLength()).toEqual(1);
             slidingSync.off(SlidingSyncEvent.RoomData, dataListener);
         });
 
         it("should be possible to retrieve list data", () => {
-            expect(slidingSync.getList(0)).toBeDefined();
-            expect(slidingSync.getList(5)).toBeNull();
-            expect(slidingSync.getListData(5)).toBeNull();
-            const syncData = slidingSync.getListData(0)!;
+            expect(slidingSync.getListParams("a")).toBeDefined();
+            expect(slidingSync.getListParams("b")).toBeNull();
+            expect(slidingSync.getListData("b")).toBeNull();
+            const syncData = slidingSync.getListData("a")!;
             expect(syncData.joinedCount).toEqual(500); // from previous test
             expect(syncData.roomIndexToRoomId).toEqual({
                 0: roomA,
@@ -467,17 +466,17 @@ describe("SlidingSync", () => {
                 .when("POST", syncUrl)
                 .check(function (req) {
                     const body = req.data;
-                    logger.log("next ranges", body.lists[0].ranges);
+                    logger.log("next ranges", body.lists["a"].ranges);
                     expect(body.lists).toBeTruthy();
-                    expect(body.lists[0]).toEqual({
+                    expect(body.lists["a"]).toEqual({
                         // only the ranges should be sent as the rest are unchanged and sticky
                         ranges: newRanges,
                     });
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [
-                        {
+                    lists: {
+                        a: {
                             count: 500,
                             ops: [
                                 {
@@ -487,15 +486,17 @@ describe("SlidingSync", () => {
                                 },
                             ],
                         },
-                    ],
+                    },
                 });
 
             const responseProcessed = listenUntil(slidingSync, "SlidingSync.Lifecycle", (state) => {
                 return state === SlidingSyncState.RequestFinished;
             });
-            slidingSync.setListRanges(0, newRanges);
+            slidingSync.setListRanges("a", newRanges);
             await httpBackend!.flushAllExpected();
             await responseProcessed;
+            // setListRanges for an invalid list key returns an error
+            await expect(slidingSync.setListRanges("idontexist", newRanges)).rejects.toBeTruthy();
         });
 
         it("should be possible to add an extra list", async () => {
@@ -513,19 +514,19 @@ describe("SlidingSync", () => {
                     const body = req.data;
                     logger.log("extra list", body);
                     expect(body.lists).toBeTruthy();
-                    expect(body.lists[0]).toEqual({
+                    expect(body.lists["a"]).toEqual({
                         // only the ranges should be sent as the rest are unchanged and sticky
                         ranges: newRanges,
                     });
-                    expect(body.lists[1]).toEqual(extraListReq);
+                    expect(body.lists["b"]).toEqual(extraListReq);
                 })
                 .respond(200, {
                     pos: "c",
-                    lists: [
-                        {
+                    lists: {
+                        a: {
                             count: 500,
                         },
-                        {
+                        b: {
                             count: 50,
                             ops: [
                                 {
@@ -535,10 +536,10 @@ describe("SlidingSync", () => {
                                 },
                             ],
                         },
-                    ],
+                    },
                 });
-            listenUntil(slidingSync, "SlidingSync.List", (listIndex, joinedCount, roomIndexToRoomId) => {
-                expect(listIndex).toEqual(1);
+            listenUntil(slidingSync, "SlidingSync.List", (listKey, joinedCount, roomIndexToRoomId) => {
+                expect(listKey).toEqual("b");
                 expect(joinedCount).toEqual(50);
                 expect(roomIndexToRoomId).toEqual({
                     0: roomA,
@@ -550,7 +551,7 @@ describe("SlidingSync", () => {
             const responseProcessed = listenUntil(slidingSync, "SlidingSync.Lifecycle", (state) => {
                 return state === SlidingSyncState.Complete;
             });
-            slidingSync.setList(1, extraListReq);
+            slidingSync.setList("b", extraListReq);
             await httpBackend!.flushAllExpected();
             await responseProcessed;
         });
@@ -559,8 +560,8 @@ describe("SlidingSync", () => {
             // move C (2) to A (0)
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "e",
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 500,
                         ops: [
                             {
@@ -574,16 +575,16 @@ describe("SlidingSync", () => {
                             },
                         ],
                     },
-                    {
+                    b: {
                         count: 50,
                     },
-                ],
+                },
             });
             let listPromise = listenUntil(
                 slidingSync,
                 "SlidingSync.List",
-                (listIndex, joinedCount, roomIndexToRoomId) => {
-                    expect(listIndex).toEqual(0);
+                (listKey, joinedCount, roomIndexToRoomId) => {
+                    expect(listKey).toEqual("a");
                     expect(joinedCount).toEqual(500);
                     expect(roomIndexToRoomId).toEqual({
                         0: roomC,
@@ -603,8 +604,8 @@ describe("SlidingSync", () => {
             // move C (0) back to A (2)
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "f",
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 500,
                         ops: [
                             {
@@ -618,13 +619,13 @@ describe("SlidingSync", () => {
                             },
                         ],
                     },
-                    {
+                    b: {
                         count: 50,
                     },
-                ],
+                },
             });
-            listPromise = listenUntil(slidingSync, "SlidingSync.List", (listIndex, joinedCount, roomIndexToRoomId) => {
-                expect(listIndex).toEqual(0);
+            listPromise = listenUntil(slidingSync, "SlidingSync.List", (listKey, joinedCount, roomIndexToRoomId) => {
+                expect(listKey).toEqual("a");
                 expect(joinedCount).toEqual(500);
                 expect(roomIndexToRoomId).toEqual({
                     0: roomA,
@@ -644,8 +645,8 @@ describe("SlidingSync", () => {
         it("should ignore invalid list indexes", async () => {
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "e",
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 500,
                         ops: [
                             {
@@ -654,16 +655,16 @@ describe("SlidingSync", () => {
                             },
                         ],
                     },
-                    {
+                    b: {
                         count: 50,
                     },
-                ],
+                },
             });
             const listPromise = listenUntil(
                 slidingSync,
                 "SlidingSync.List",
-                (listIndex, joinedCount, roomIndexToRoomId) => {
-                    expect(listIndex).toEqual(0);
+                (listKey, joinedCount, roomIndexToRoomId) => {
+                    expect(listKey).toEqual("a");
                     expect(joinedCount).toEqual(500);
                     expect(roomIndexToRoomId).toEqual({
                         0: roomA,
@@ -684,8 +685,8 @@ describe("SlidingSync", () => {
         it("should be possible to update a list", async () => {
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "g",
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 42,
                         ops: [
                             {
@@ -699,13 +700,13 @@ describe("SlidingSync", () => {
                             },
                         ],
                     },
-                    {
+                    b: {
                         count: 50,
                     },
-                ],
+                },
             });
             // update the list with a new filter
-            slidingSync.setList(0, {
+            slidingSync.setList("a", {
                 filters: {
                     is_encrypted: true,
                 },
@@ -714,8 +715,8 @@ describe("SlidingSync", () => {
             const listPromise = listenUntil(
                 slidingSync,
                 "SlidingSync.List",
-                (listIndex, joinedCount, roomIndexToRoomId) => {
-                    expect(listIndex).toEqual(0);
+                (listKey, joinedCount, roomIndexToRoomId) => {
+                    expect(listKey).toEqual("a");
                     expect(joinedCount).toEqual(42);
                     expect(roomIndexToRoomId).toEqual({
                         0: roomB,
@@ -738,12 +739,12 @@ describe("SlidingSync", () => {
                 0: roomB,
                 1: roomC,
             };
-            expect(slidingSync.getListData(0)!.roomIndexToRoomId).toEqual(indexToRoomId);
+            expect(slidingSync.getListData("a")!.roomIndexToRoomId).toEqual(indexToRoomId);
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "f",
                 // currently the list is [B,C] so we will insert D then immediately delete it
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 500,
                         ops: [
                             {
@@ -761,16 +762,16 @@ describe("SlidingSync", () => {
                             },
                         ],
                     },
-                    {
+                    b: {
                         count: 50,
                     },
-                ],
+                },
             });
             const listPromise = listenUntil(
                 slidingSync,
                 "SlidingSync.List",
-                (listIndex, joinedCount, roomIndexToRoomId) => {
-                    expect(listIndex).toEqual(0);
+                (listKey, joinedCount, roomIndexToRoomId) => {
+                    expect(listKey).toEqual("a");
                     expect(joinedCount).toEqual(500);
                     expect(roomIndexToRoomId).toEqual(indexToRoomId);
                     return true;
@@ -785,14 +786,14 @@ describe("SlidingSync", () => {
         });
 
         it("should handle deletions correctly", async () => {
-            expect(slidingSync.getListData(0)!.roomIndexToRoomId).toEqual({
+            expect(slidingSync.getListData("a")!.roomIndexToRoomId).toEqual({
                 0: roomB,
                 1: roomC,
             });
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "g",
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 499,
                         ops: [
                             {
@@ -801,16 +802,16 @@ describe("SlidingSync", () => {
                             },
                         ],
                     },
-                    {
+                    b: {
                         count: 50,
                     },
-                ],
+                },
             });
             const listPromise = listenUntil(
                 slidingSync,
                 "SlidingSync.List",
-                (listIndex, joinedCount, roomIndexToRoomId) => {
-                    expect(listIndex).toEqual(0);
+                (listKey, joinedCount, roomIndexToRoomId) => {
+                    expect(listKey).toEqual("a");
                     expect(joinedCount).toEqual(499);
                     expect(roomIndexToRoomId).toEqual({
                         0: roomC,
@@ -827,13 +828,13 @@ describe("SlidingSync", () => {
         });
 
         it("should handle insertions correctly", async () => {
-            expect(slidingSync.getListData(0)!.roomIndexToRoomId).toEqual({
+            expect(slidingSync.getListData("a")!.roomIndexToRoomId).toEqual({
                 0: roomC,
             });
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "h",
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 500,
                         ops: [
                             {
@@ -843,16 +844,16 @@ describe("SlidingSync", () => {
                             },
                         ],
                     },
-                    {
+                    b: {
                         count: 50,
                     },
-                ],
+                },
             });
             let listPromise = listenUntil(
                 slidingSync,
                 "SlidingSync.List",
-                (listIndex, joinedCount, roomIndexToRoomId) => {
-                    expect(listIndex).toEqual(0);
+                (listKey, joinedCount, roomIndexToRoomId) => {
+                    expect(listKey).toEqual("a");
                     expect(joinedCount).toEqual(500);
                     expect(roomIndexToRoomId).toEqual({
                         0: roomC,
@@ -870,8 +871,8 @@ describe("SlidingSync", () => {
 
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "h",
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 501,
                         ops: [
                             {
@@ -881,13 +882,13 @@ describe("SlidingSync", () => {
                             },
                         ],
                     },
-                    {
+                    b: {
                         count: 50,
                     },
-                ],
+                },
             });
-            listPromise = listenUntil(slidingSync, "SlidingSync.List", (listIndex, joinedCount, roomIndexToRoomId) => {
-                expect(listIndex).toEqual(0);
+            listPromise = listenUntil(slidingSync, "SlidingSync.List", (listKey, joinedCount, roomIndexToRoomId) => {
+                expect(listKey).toEqual("a");
                 expect(joinedCount).toEqual(501);
                 expect(roomIndexToRoomId).toEqual({
                     0: roomC,
@@ -910,11 +911,14 @@ describe("SlidingSync", () => {
         it("should handle insertions with a spurious DELETE correctly", async () => {
             slidingSync = new SlidingSync(
                 proxyBaseUrl,
-                [
-                    {
-                        ranges: [[0, 20]],
-                    },
-                ],
+                new Map([
+                    [
+                        "a",
+                        {
+                            ranges: [[0, 20]],
+                        },
+                    ],
+                ]),
                 {},
                 client!,
                 1,
@@ -922,22 +926,22 @@ describe("SlidingSync", () => {
             // initially start with nothing
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "a",
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 0,
                         ops: [],
                     },
-                ],
+                },
             });
             slidingSync.start();
             await httpBackend!.flushAllExpected();
-            expect(slidingSync.getListData(0)!.roomIndexToRoomId).toEqual({});
+            expect(slidingSync.getListData("a")!.roomIndexToRoomId).toEqual({});
 
             // insert a room
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "b",
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 1,
                         ops: [
                             {
@@ -951,18 +955,18 @@ describe("SlidingSync", () => {
                             },
                         ],
                     },
-                ],
+                },
             });
             await httpBackend!.flushAllExpected();
-            expect(slidingSync.getListData(0)!.roomIndexToRoomId).toEqual({
+            expect(slidingSync.getListData("a")!.roomIndexToRoomId).toEqual({
                 0: roomA,
             });
 
             // insert another room
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "c",
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 1,
                         ops: [
                             {
@@ -976,10 +980,10 @@ describe("SlidingSync", () => {
                             },
                         ],
                     },
-                ],
+                },
             });
             await httpBackend!.flushAllExpected();
-            expect(slidingSync.getListData(0)!.roomIndexToRoomId).toEqual({
+            expect(slidingSync.getListData("a")!.roomIndexToRoomId).toEqual({
                 0: roomB,
                 1: roomA,
             });
@@ -987,8 +991,8 @@ describe("SlidingSync", () => {
             // insert a final room
             httpBackend!.when("POST", syncUrl).respond(200, {
                 pos: "c",
-                lists: [
-                    {
+                lists: {
+                    a: {
                         count: 1,
                         ops: [
                             {
@@ -1002,10 +1006,10 @@ describe("SlidingSync", () => {
                             },
                         ],
                     },
-                ],
+                },
             });
             await httpBackend!.flushAllExpected();
-            expect(slidingSync.getListData(0)!.roomIndexToRoomId).toEqual({
+            expect(slidingSync.getListData("a")!.roomIndexToRoomId).toEqual({
                 0: roomC,
                 1: roomB,
                 2: roomA,
@@ -1028,7 +1032,7 @@ describe("SlidingSync", () => {
                 required_state: [["m.room.name", ""]],
             };
             // add the subscription
-            slidingSync = new SlidingSync(proxyBaseUrl, [], roomSubInfo, client!, 1);
+            slidingSync = new SlidingSync(proxyBaseUrl, new Map(), roomSubInfo, client!, 1);
             // modification before SlidingSync.start()
             const subscribePromise = slidingSync.modifyRoomSubscriptions(new Set([roomId]));
             let txnId: string | undefined;
@@ -1046,7 +1050,7 @@ describe("SlidingSync", () => {
                     return {
                         pos: "aaa",
                         txn_id: txnId,
-                        lists: [],
+                        lists: {},
                         extensions: {},
                         rooms: {
                             [roomId]: {
@@ -1065,7 +1069,7 @@ describe("SlidingSync", () => {
             const newList = {
                 ranges: [[0, 20]],
             };
-            const promise = slidingSync.setList(0, newList);
+            const promise = slidingSync.setList("a", newList);
             let txnId: string | undefined;
             httpBackend!
                 .when("POST", syncUrl)
@@ -1073,7 +1077,7 @@ describe("SlidingSync", () => {
                     const body = req.data;
                     logger.debug("got ", body);
                     expect(body.room_subscriptions).toBeFalsy();
-                    expect(body.lists[0]).toEqual(newList);
+                    expect(body.lists["a"]).toEqual(newList);
                     expect(body.txn_id).toBeTruthy();
                     txnId = body.txn_id;
                 })
@@ -1081,7 +1085,7 @@ describe("SlidingSync", () => {
                     return {
                         pos: "bbb",
                         txn_id: txnId,
-                        lists: [{ count: 5 }],
+                        lists: { a: { count: 5 } },
                         extensions: {},
                     };
                 });
@@ -1090,7 +1094,7 @@ describe("SlidingSync", () => {
             expect(txnId).toBeDefined();
         });
         it("should resolve setListRanges during a connection", async () => {
-            const promise = slidingSync.setListRanges(0, [[20, 40]]);
+            const promise = slidingSync.setListRanges("a", [[20, 40]]);
             let txnId: string | undefined;
             httpBackend!
                 .when("POST", syncUrl)
@@ -1098,7 +1102,7 @@ describe("SlidingSync", () => {
                     const body = req.data;
                     logger.debug("got ", body);
                     expect(body.room_subscriptions).toBeFalsy();
-                    expect(body.lists[0]).toEqual({
+                    expect(body.lists["a"]).toEqual({
                         ranges: [[20, 40]],
                     });
                     expect(body.txn_id).toBeTruthy();
@@ -1108,7 +1112,7 @@ describe("SlidingSync", () => {
                     return {
                         pos: "ccc",
                         txn_id: txnId,
-                        lists: [{ count: 5 }],
+                        lists: { a: { count: 5 } },
                         extensions: {},
                     };
                 });
@@ -1150,10 +1154,10 @@ describe("SlidingSync", () => {
             const pushTxn = function (req: MockHttpBackend["requests"][0]) {
                 gotTxnIds.push(req.data.txn_id);
             };
-            const failPromise = slidingSync.setListRanges(0, [[20, 40]]);
+            const failPromise = slidingSync.setListRanges("a", [[20, 40]]);
             httpBackend!.when("POST", syncUrl).check(pushTxn).respond(200, { pos: "e" }); // missing txn_id
             await httpBackend!.flushAllExpected();
-            const failPromise2 = slidingSync.setListRanges(0, [[60, 70]]);
+            const failPromise2 = slidingSync.setListRanges("a", [[60, 70]]);
             httpBackend!.when("POST", syncUrl).check(pushTxn).respond(200, { pos: "f" }); // missing txn_id
             await httpBackend!.flushAllExpected();
 
@@ -1162,7 +1166,7 @@ describe("SlidingSync", () => {
             expect(failPromise).rejects.toEqual(gotTxnIds[0]);
             expect(failPromise2).rejects.toEqual(gotTxnIds[1]);
 
-            const okPromise = slidingSync.setListRanges(0, [[0, 20]]);
+            const okPromise = slidingSync.setListRanges("a", [[0, 20]]);
             let txnId: string | undefined;
             httpBackend!
                 .when("POST", syncUrl)
@@ -1187,10 +1191,10 @@ describe("SlidingSync", () => {
             const pushTxn = function (req: MockHttpBackend["requests"][0]) {
                 gotTxnIds.push(req.data?.txn_id);
             };
-            const A = slidingSync.setListRanges(0, [[20, 40]]);
+            const A = slidingSync.setListRanges("a", [[20, 40]]);
             httpBackend!.when("POST", syncUrl).check(pushTxn).respond(200, { pos: "A" });
             await httpBackend!.flushAllExpected();
-            const B = slidingSync.setListRanges(0, [[60, 70]]);
+            const B = slidingSync.setListRanges("a", [[60, 70]]);
             httpBackend!.when("POST", syncUrl).check(pushTxn).respond(200, { pos: "B" }); // missing txn_id
             await httpBackend!.flushAllExpected();
 
@@ -1198,7 +1202,7 @@ describe("SlidingSync", () => {
             // which is a fail.
             expect(A).rejects.toEqual(gotTxnIds[0]);
 
-            const C = slidingSync.setListRanges(0, [[0, 20]]);
+            const C = slidingSync.setListRanges("a", [[0, 20]]);
             let pendingC = true;
             C.finally(() => {
                 pendingC = false;
@@ -1219,7 +1223,7 @@ describe("SlidingSync", () => {
             expect(pendingC).toBe(true); // C is pending still
         });
         it("should do nothing for unknown txn_ids", async () => {
-            const promise = slidingSync.setListRanges(0, [[20, 40]]);
+            const promise = slidingSync.setListRanges("a", [[20, 40]]);
             let pending = true;
             promise.finally(() => {
                 pending = false;
@@ -1231,7 +1235,7 @@ describe("SlidingSync", () => {
                     const body = req.data;
                     logger.debug("got ", body);
                     expect(body.room_subscriptions).toBeFalsy();
-                    expect(body.lists[0]).toEqual({
+                    expect(body.lists["a"]).toEqual({
                         ranges: [[20, 40]],
                     });
                     expect(body.txn_id).toBeTruthy();
@@ -1241,7 +1245,7 @@ describe("SlidingSync", () => {
                     return {
                         pos: "ccc",
                         txn_id: "bogus transaction id",
-                        lists: [{ count: 5 }],
+                        lists: { a: { count: 5 } },
                         extensions: {},
                     };
                 });
@@ -1279,7 +1283,7 @@ describe("SlidingSync", () => {
         };
 
         it("should be possible to use custom subscriptions on startup", async () => {
-            const slidingSync = new SlidingSync(proxyBaseUrl, [], defaultSub, client!, 1);
+            const slidingSync = new SlidingSync(proxyBaseUrl, new Map(), defaultSub, client!, 1);
             // the intention is for clients to set this up at startup
             slidingSync.addCustomSubscription(customSubName1, customSub1);
             slidingSync.addCustomSubscription(customSubName2, customSub2);
@@ -1302,7 +1306,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {},
                 });
@@ -1312,7 +1316,7 @@ describe("SlidingSync", () => {
         });
 
         it("should be possible to use custom subscriptions mid-connection", async () => {
-            const slidingSync = new SlidingSync(proxyBaseUrl, [], defaultSub, client!, 1);
+            const slidingSync = new SlidingSync(proxyBaseUrl, new Map(), defaultSub, client!, 1);
             // the intention is for clients to set this up at startup
             slidingSync.addCustomSubscription(customSubName1, customSub1);
             slidingSync.addCustomSubscription(customSubName2, customSub2);
@@ -1326,7 +1330,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {},
                 });
@@ -1344,7 +1348,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {},
                 });
@@ -1363,7 +1367,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {},
                 });
@@ -1383,7 +1387,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {},
                 });
@@ -1395,7 +1399,7 @@ describe("SlidingSync", () => {
         });
 
         it("uses the default subscription for unknown subscription names", async () => {
-            const slidingSync = new SlidingSync(proxyBaseUrl, [], defaultSub, client!, 1);
+            const slidingSync = new SlidingSync(proxyBaseUrl, new Map(), defaultSub, client!, 1);
             slidingSync.addCustomSubscription(customSubName1, customSub1);
             slidingSync.useCustomSubscription(roomA, "unknown name");
             slidingSync.modifyRoomSubscriptions(new Set<string>([roomA]));
@@ -1410,7 +1414,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {},
                 });
@@ -1420,7 +1424,7 @@ describe("SlidingSync", () => {
         });
 
         it("should not be possible to add/modify an already added custom subscription", async () => {
-            const slidingSync = new SlidingSync(proxyBaseUrl, [], defaultSub, client!, 1);
+            const slidingSync = new SlidingSync(proxyBaseUrl, new Map(), defaultSub, client!, 1);
             slidingSync.addCustomSubscription(customSubName1, customSub1);
             slidingSync.addCustomSubscription(customSubName1, customSub2);
             slidingSync.useCustomSubscription(roomA, customSubName1);
@@ -1436,7 +1440,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {},
                 });
@@ -1446,7 +1450,7 @@ describe("SlidingSync", () => {
         });
 
         it("should change the custom subscription if they are different", async () => {
-            const slidingSync = new SlidingSync(proxyBaseUrl, [], defaultSub, client!, 1);
+            const slidingSync = new SlidingSync(proxyBaseUrl, new Map(), defaultSub, client!, 1);
             slidingSync.addCustomSubscription(customSubName1, customSub1);
             slidingSync.addCustomSubscription(customSubName2, customSub2);
             slidingSync.useCustomSubscription(roomA, customSubName1);
@@ -1463,7 +1467,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {},
                 });
@@ -1484,7 +1488,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {},
                 });
@@ -1506,7 +1510,7 @@ describe("SlidingSync", () => {
                 })
                 .respond(200, {
                     pos: "b",
-                    lists: [],
+                    lists: {},
                     extensions: {},
                     rooms: {},
                 });
@@ -1559,7 +1563,7 @@ describe("SlidingSync", () => {
         };
 
         it("should be able to register an extension", async () => {
-            slidingSync = new SlidingSync(proxyBaseUrl, [], {}, client!, 1);
+            slidingSync = new SlidingSync(proxyBaseUrl, new Map(), {}, client!, 1);
             slidingSync.registerExtension(extPre);
 
             const callbackOrder: string[] = [];
@@ -1684,7 +1688,7 @@ describe("SlidingSync", () => {
         });
 
         it("is not possible to register the same extension name twice", async () => {
-            slidingSync = new SlidingSync(proxyBaseUrl, [], {}, client!, 1);
+            slidingSync = new SlidingSync(proxyBaseUrl, new Map(), {}, client!, 1);
             slidingSync.registerExtension(extPre);
             expect(() => {
                 slidingSync.registerExtension(extPre);

spec/test-utils/client.ts

@@ -60,6 +60,7 @@ export const getMockClientWithEventEmitter = (
  */
 export const mockClientMethodsUser = (userId = "@alice:domain") => ({
     getUserId: jest.fn().mockReturnValue(userId),
+    getSafeUserId: jest.fn().mockReturnValue(userId),
     getUser: jest.fn().mockReturnValue(new User(userId)),
     isGuest: jest.fn().mockReturnValue(false),
     mxcUrlToHttp: jest.fn().mockReturnValue("mock-mxcUrlToHttp"),

spec/test-utils/test-utils.ts

@@ -403,3 +403,15 @@ export const mkPusher = (extra: Partial<IPusher> = {}): IPusher => ({
     pushkey: "pushpush",
     ...extra,
 });
+
+/**
+ * a list of the supported crypto implementations, each with a callback to initialise that implementation
+ * for the given client
+ */
+export const CRYPTO_BACKENDS: Record<string, InitCrypto> = {};
+export type InitCrypto = (_: MatrixClient) => Promise<void>;
+
+CRYPTO_BACKENDS["rust-sdk"] = (client: MatrixClient) => client.initRustCrypto();
+if (global.Olm) {
+    CRYPTO_BACKENDS["libolm"] = (client: MatrixClient) => client.initCrypto();
+}

spec/test-utils/webrtc.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2022 The Matrix.org Foundation C.I.C.
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -476,7 +476,7 @@ export class MockCallMatrixClient extends TypedEventEmitter<EmittedEvents, Emitt
     public getRooms = jest.fn<Room[], []>().mockReturnValue([]);
     public getRoom = jest.fn();
 
-    public supportsExperimentalThreads(): boolean {
+    public supportsThreads(): boolean {
         return true;
     }
     public async decryptEventIfNeeded(): Promise<void> {}

spec/unit/content-helpers.spec.ts

@@ -14,8 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { REFERENCE_RELATION } from "matrix-events-sdk";
-
 import { LocationAssetType, M_ASSET, M_LOCATION, M_TIMESTAMP } from "../../src/@types/location";
 import { M_TOPIC } from "../../src/@types/topic";
 import {
@@ -25,6 +23,7 @@ import {
     parseBeaconContent,
     parseTopicContent,
 } from "../../src/content-helpers";
+import { REFERENCE_RELATION } from "../../src/@types/extensible_events";
 
 describe("Beacon content helpers", () => {
     describe("makeBeaconInfoContent()", () => {

spec/unit/crypto.spec.ts

@@ -254,6 +254,7 @@ describe("Crypto", function () {
                 sendToDevice: jest.fn(),
                 getKeyBackupVersion: jest.fn(),
                 isGuest: jest.fn(),
+                emit: jest.fn(),
             } as unknown as MatrixClient;
             mockRoomList = {} as unknown as RoomList;
 

spec/unit/crypto/algorithms/megolm.spec.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2022 The Matrix.org Foundation C.I.C.
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@ limitations under the License.
 
 import { mocked, MockedObject } from "jest-mock";
 
+import type { DeviceInfoMap } from "../../../../src/crypto/DeviceList";
 import "../../../olm-loader";
 import type { OutboundGroupSession } from "@matrix-org/olm";
 import * as algorithms from "../../../../src/crypto/algorithms";
@@ -33,6 +34,7 @@ import { ClientEvent, MatrixClient, RoomMember } from "../../../../src";
 import { DeviceInfo, IDevice } from "../../../../src/crypto/deviceinfo";
 import { DeviceTrustLevel } from "../../../../src/crypto/CrossSigning";
 import { MegolmEncryption as MegolmEncryptionClass } from "../../../../src/crypto/algorithms/megolm";
+import { sleep } from "../../../../src/utils";
 
 const MegolmDecryption = algorithms.DECRYPTION_CLASSES.get("m.megolm.v1.aes-sha2")!;
 const MegolmEncryption = algorithms.ENCRYPTION_CLASSES.get("m.megolm.v1.aes-sha2")!;
@@ -58,6 +60,12 @@ describe("MegolmDecryption", function () {
 
     beforeEach(async function () {
         mockCrypto = testUtils.mock(Crypto, "Crypto") as MockedObject<Crypto>;
+
+        // @ts-ignore assigning to readonly prop
+        mockCrypto.backupManager = {
+            backupGroupSession: () => {},
+        };
+
         mockBaseApis = {
             claimOneTimeKeys: jest.fn(),
             sendToDevice: jest.fn(),
@@ -314,10 +322,6 @@ describe("MegolmDecryption", function () {
             let olmDevice: OlmDevice;
 
             beforeEach(async () => {
-                // @ts-ignore assigning to readonly prop
-                mockCrypto.backupManager = {
-                    backupGroupSession: () => {},
-                };
                 const cryptoStore = new MemoryCryptoStore();
 
                 olmDevice = new OlmDevice(cryptoStore);
@@ -387,8 +391,10 @@ describe("MegolmDecryption", function () {
                 mockCrypto.baseApis = mockBaseApis;
 
                 mockRoom = {
+                    roomId: ROOM_ID,
                     getEncryptionTargetMembers: jest.fn().mockReturnValue([{ userId: "@alice:home.server" }]),
                     getBlacklistUnverifiedDevices: jest.fn().mockReturnValue(false),
+                    shouldEncryptForInvitedMembers: jest.fn().mockReturnValue(false),
                 } as unknown as Room;
             });
 
@@ -513,6 +519,78 @@ describe("MegolmDecryption", function () {
         });
     });
 
+    describe("prepareToEncrypt", () => {
+        let megolm: MegolmEncryptionClass;
+        let room: jest.Mocked<Room>;
+
+        const deviceMap: DeviceInfoMap = {
+            "user-a": {
+                "device-a": new DeviceInfo("device-a"),
+                "device-b": new DeviceInfo("device-b"),
+                "device-c": new DeviceInfo("device-c"),
+            },
+            "user-b": {
+                "device-d": new DeviceInfo("device-d"),
+                "device-e": new DeviceInfo("device-e"),
+                "device-f": new DeviceInfo("device-f"),
+            },
+            "user-c": {
+                "device-g": new DeviceInfo("device-g"),
+                "device-h": new DeviceInfo("device-h"),
+                "device-i": new DeviceInfo("device-i"),
+            },
+        };
+
+        beforeEach(() => {
+            room = testUtils.mock(Room, "Room") as jest.Mocked<Room>;
+            room.getEncryptionTargetMembers.mockImplementation(async () => [
+                new RoomMember(room.roomId, "@user:example.org"),
+            ]);
+            room.getBlacklistUnverifiedDevices.mockReturnValue(false);
+
+            mockCrypto.downloadKeys.mockImplementation(async () => deviceMap);
+
+            mockCrypto.checkDeviceTrust.mockImplementation(() => new DeviceTrustLevel(true, true, true, true));
+
+            const olmDevice = new OlmDevice(new MemoryCryptoStore());
+            megolm = new MegolmEncryptionClass({
+                userId: "@user:id",
+                deviceId: "12345",
+                crypto: mockCrypto,
+                olmDevice,
+                baseApis: mockBaseApis,
+                roomId: room.roomId,
+                config: {
+                    algorithm: "m.megolm.v1.aes-sha2",
+                    rotation_period_ms: 9_999_999,
+                },
+            });
+        });
+
+        it("checks each device", async () => {
+            megolm.prepareToEncrypt(room);
+            //@ts-ignore private member access, gross
+            await megolm.encryptionPreparation?.promise;
+
+            for (const userId in deviceMap) {
+                for (const deviceId in deviceMap[userId]) {
+                    expect(mockCrypto.checkDeviceTrust).toHaveBeenCalledWith(userId, deviceId);
+                }
+            }
+        });
+
+        it("is cancellable", async () => {
+            const stop = megolm.prepareToEncrypt(room);
+
+            const before = mockCrypto.checkDeviceTrust.mock.calls.length;
+            stop();
+
+            // Ensure that no more devices were checked after cancellation.
+            await sleep(10);
+            expect(mockCrypto.checkDeviceTrust).toHaveBeenCalledTimes(before);
+        });
+    });
+
     it("notifies devices that have been blocked", async function () {
         const aliceClient = new TestClient("@alice:example.com", "alicedevice").client;
         const bobClient1 = new TestClient("@bob:example.com", "bobdevice1").client;

spec/unit/crypto/verification/sas.spec.ts

@@ -215,7 +215,7 @@ describe("SAS verification", function () {
             ]);
 
             // make sure that it uses the preferred method
-            expect(macMethod).toBe("org.matrix.msc3783.hkdf-hmac-sha256");
+            expect(macMethod).toBe("hkdf-hmac-sha256.v2");
             expect(keyAgreement).toBe("curve25519-hkdf-sha256");
 
             // make sure Alice and Bob verified each other

spec/unit/event-timeline-set.spec.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2022 The Matrix.org Foundation C.I.C.
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -147,7 +147,7 @@ describe("EventTimelineSet", () => {
         let thread: Thread;
 
         beforeEach(() => {
-            (client.supportsExperimentalThreads as jest.Mock).mockReturnValue(true);
+            (client.supportsThreads as jest.Mock).mockReturnValue(true);
             thread = new Thread("!thread_id:server", messageEvent, { room, client });
         });
 
@@ -206,7 +206,7 @@ describe("EventTimelineSet", () => {
         });
 
         it("should allow edits to be added to thread timeline", async () => {
-            jest.spyOn(client, "supportsExperimentalThreads").mockReturnValue(true);
+            jest.spyOn(client, "supportsThreads").mockReturnValue(true);
             jest.spyOn(client, "getEventMapper").mockReturnValue(eventMapperFor(client, {}));
             Thread.hasServerSideSupport = FeatureSupport.Stable;
 
@@ -393,7 +393,7 @@ describe("EventTimelineSet", () => {
         let thread: Thread;
 
         beforeEach(() => {
-            (client.supportsExperimentalThreads as jest.Mock).mockReturnValue(true);
+            (client.supportsThreads as jest.Mock).mockReturnValue(true);
             thread = new Thread("!thread_id:server", messageEvent, { room, client });
         });
 

spec/unit/extensible_events_v1/ExtensibleEvent.spec.ts

@@ -0,0 +1,41 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { ExtensibleEventType, IPartialEvent } from "../../../src/@types/extensible_events";
+import { ExtensibleEvent } from "../../../src/extensible_events_v1/ExtensibleEvent";
+
+class MockEvent extends ExtensibleEvent<any> {
+    public constructor(wireEvent: IPartialEvent<any>) {
+        super(wireEvent);
+    }
+
+    public serialize(): IPartialEvent<object> {
+        throw new Error("Not implemented for tests");
+    }
+
+    public isEquivalentTo(primaryEventType: ExtensibleEventType): boolean {
+        throw new Error("Not implemented for tests");
+    }
+}
+
+describe("ExtensibleEvent", () => {
+    it("should expose the wire event directly", () => {
+        const input: IPartialEvent<any> = { type: "org.example.custom", content: { hello: "world" } };
+        const event = new MockEvent(input);
+        expect(event.wireFormat).toBe(input);
+        expect(event.wireContent).toBe(input.content);
+    });
+});

spec/unit/extensible_events_v1/MessageEvent.spec.ts

@@ -0,0 +1,156 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import {
+    ExtensibleAnyMessageEventContent,
+    IPartialEvent,
+    M_HTML,
+    M_MESSAGE,
+    M_TEXT,
+} from "../../../src/@types/extensible_events";
+import { MessageEvent } from "../../../src/extensible_events_v1/MessageEvent";
+import { InvalidEventError } from "../../../src/extensible_events_v1/InvalidEventError";
+
+describe("MessageEvent", () => {
+    it("should parse m.text", () => {
+        const input: IPartialEvent<ExtensibleAnyMessageEventContent> = {
+            type: "org.example.message-like",
+            content: {
+                [M_TEXT.name]: "Text here",
+            },
+        };
+        const message = new MessageEvent(input);
+        expect(message.text).toBe("Text here");
+        expect(message.html).toBeFalsy();
+        expect(message.renderings.length).toBe(1);
+        expect(message.renderings.some((r) => r.mimetype === "text/plain" && r.body === "Text here")).toBe(true);
+    });
+
+    it("should parse m.html", () => {
+        const input: IPartialEvent<ExtensibleAnyMessageEventContent> = {
+            type: "org.example.message-like",
+            content: {
+                [M_TEXT.name]: "Text here",
+                [M_HTML.name]: "HTML here",
+            },
+        };
+        const message = new MessageEvent(input);
+        expect(message.text).toBe("Text here");
+        expect(message.html).toBe("HTML here");
+        expect(message.renderings.length).toBe(2);
+        expect(message.renderings.some((r) => r.mimetype === "text/plain" && r.body === "Text here")).toBe(true);
+        expect(message.renderings.some((r) => r.mimetype === "text/html" && r.body === "HTML here")).toBe(true);
+    });
+
+    it("should parse m.message", () => {
+        const input: IPartialEvent<ExtensibleAnyMessageEventContent> = {
+            type: "org.example.message-like",
+            content: {
+                [M_MESSAGE.name]: [
+                    { body: "Text here", mimetype: "text/plain" },
+                    { body: "HTML here", mimetype: "text/html" },
+                    { body: "MD here", mimetype: "text/markdown" },
+                ],
+
+                // These should be ignored
+                [M_TEXT.name]: "WRONG Text here",
+                [M_HTML.name]: "WRONG HTML here",
+            },
+        };
+        const message = new MessageEvent(input);
+        expect(message.text).toBe("Text here");
+        expect(message.html).toBe("HTML here");
+        expect(message.renderings.length).toBe(3);
+        expect(message.renderings.some((r) => r.mimetype === "text/plain" && r.body === "Text here")).toBe(true);
+        expect(message.renderings.some((r) => r.mimetype === "text/html" && r.body === "HTML here")).toBe(true);
+        expect(message.renderings.some((r) => r.mimetype === "text/markdown" && r.body === "MD here")).toBe(true);
+    });
+
+    it("should fail to parse missing text", () => {
+        const input: IPartialEvent<ExtensibleAnyMessageEventContent> = {
+            type: "org.example.message-like",
+            content: {
+                hello: "world",
+            } as any, // force invalid type
+        };
+        expect(() => new MessageEvent(input)).toThrow(
+            new InvalidEventError("Missing textual representation for event"),
+        );
+    });
+
+    it("should fail to parse missing plain text in m.message", () => {
+        const input: IPartialEvent<ExtensibleAnyMessageEventContent> = {
+            type: "org.example.message-like",
+            content: {
+                [M_MESSAGE.name]: [{ body: "HTML here", mimetype: "text/html" }],
+            },
+        };
+        expect(() => new MessageEvent(input)).toThrow(
+            new InvalidEventError("m.message is missing a plain text representation"),
+        );
+    });
+
+    it("should fail to parse non-array m.message", () => {
+        const input: IPartialEvent<ExtensibleAnyMessageEventContent> = {
+            type: "org.example.message-like",
+            content: {
+                [M_MESSAGE.name]: "invalid",
+            } as any, // force invalid type
+        };
+        expect(() => new MessageEvent(input)).toThrow(new InvalidEventError("m.message contents must be an array"));
+    });
+
+    describe("from & serialize", () => {
+        it("should serialize to a legacy fallback", () => {
+            const message = MessageEvent.from("Text here", "HTML here");
+            expect(message.text).toBe("Text here");
+            expect(message.html).toBe("HTML here");
+            expect(message.renderings.length).toBe(2);
+            expect(message.renderings.some((r) => r.mimetype === "text/plain" && r.body === "Text here")).toBe(true);
+            expect(message.renderings.some((r) => r.mimetype === "text/html" && r.body === "HTML here")).toBe(true);
+
+            const serialized = message.serialize();
+            expect(serialized.type).toBe("m.room.message");
+            expect(serialized.content).toMatchObject({
+                [M_MESSAGE.name]: [
+                    { body: "Text here", mimetype: "text/plain" },
+                    { body: "HTML here", mimetype: "text/html" },
+                ],
+                body: "Text here",
+                msgtype: "m.text",
+                format: "org.matrix.custom.html",
+                formatted_body: "HTML here",
+            });
+        });
+
+        it("should serialize non-html content to a legacy fallback", () => {
+            const message = MessageEvent.from("Text here");
+            expect(message.text).toBe("Text here");
+            expect(message.renderings.length).toBe(1);
+            expect(message.renderings.some((r) => r.mimetype === "text/plain" && r.body === "Text here")).toBe(true);
+
+            const serialized = message.serialize();
+            expect(serialized.type).toBe("m.room.message");
+            expect(serialized.content).toMatchObject({
+                [M_TEXT.name]: "Text here",
+                body: "Text here",
+                msgtype: "m.text",
+                format: undefined,
+                formatted_body: undefined,
+            });
+        });
+    });
+});

spec/unit/extensible_events_v1/PollEndEvent.spec.ts

@@ -0,0 +1,107 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { PollEndEventContent, M_POLL_END } from "../../../src/@types/polls";
+import { IPartialEvent, REFERENCE_RELATION, M_TEXT } from "../../../src/@types/extensible_events";
+import { PollEndEvent } from "../../../src/extensible_events_v1/PollEndEvent";
+import { InvalidEventError } from "../../../src/extensible_events_v1/InvalidEventError";
+
+describe("PollEndEvent", () => {
+    // Note: throughout these tests we don't really bother testing that
+    // MessageEvent is doing its job. It has its own tests to worry about.
+
+    it("should parse a poll closure", () => {
+        const input: IPartialEvent<PollEndEventContent> = {
+            type: M_POLL_END.name,
+            content: {
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                    event_id: "$poll",
+                },
+                [M_POLL_END.name]: {},
+                [M_TEXT.name]: "Poll closed",
+            },
+        };
+        const event = new PollEndEvent(input);
+        expect(event.pollEventId).toBe("$poll");
+        expect(event.closingMessage.text).toBe("Poll closed");
+    });
+
+    it("should fail to parse a missing relationship", () => {
+        const input: IPartialEvent<PollEndEventContent> = {
+            type: M_POLL_END.name,
+            content: {
+                [M_POLL_END.name]: {},
+                [M_TEXT.name]: "Poll closed",
+            } as any, // force invalid type
+        };
+        expect(() => new PollEndEvent(input)).toThrow(
+            new InvalidEventError("Relationship must be a reference to an event"),
+        );
+    });
+
+    it("should fail to parse a missing relationship event ID", () => {
+        const input: IPartialEvent<PollEndEventContent> = {
+            type: M_POLL_END.name,
+            content: {
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                },
+                [M_POLL_END.name]: {},
+                [M_TEXT.name]: "Poll closed",
+            } as any, // force invalid type
+        };
+        expect(() => new PollEndEvent(input)).toThrow(
+            new InvalidEventError("Relationship must be a reference to an event"),
+        );
+    });
+
+    it("should fail to parse an improper relationship", () => {
+        const input: IPartialEvent<PollEndEventContent> = {
+            type: M_POLL_END.name,
+            content: {
+                "m.relates_to": {
+                    rel_type: "org.example.not-relationship",
+                    event_id: "$poll",
+                },
+                [M_POLL_END.name]: {},
+                [M_TEXT.name]: "Poll closed",
+            } as any, // force invalid type
+        };
+        expect(() => new PollEndEvent(input)).toThrow(
+            new InvalidEventError("Relationship must be a reference to an event"),
+        );
+    });
+
+    describe("from & serialize", () => {
+        it("should serialize to a poll end event", () => {
+            const event = PollEndEvent.from("$poll", "Poll closed");
+            expect(event.pollEventId).toBe("$poll");
+            expect(event.closingMessage.text).toBe("Poll closed");
+
+            const serialized = event.serialize();
+            expect(M_POLL_END.matches(serialized.type)).toBe(true);
+            expect(serialized.content).toMatchObject({
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                    event_id: "$poll",
+                },
+                [M_POLL_END.name]: {},
+                [M_TEXT.name]: expect.any(String), // tested by MessageEvent tests
+            });
+        });
+    });
+});

spec/unit/extensible_events_v1/PollResponseEvent.spec.ts

@@ -0,0 +1,277 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { M_TEXT, IPartialEvent, REFERENCE_RELATION } from "../../../src/@types/extensible_events";
+import {
+    M_POLL_START,
+    M_POLL_KIND_DISCLOSED,
+    PollResponseEventContent,
+    M_POLL_RESPONSE,
+} from "../../../src/@types/polls";
+import { PollStartEvent } from "../../../src/extensible_events_v1/PollStartEvent";
+import { InvalidEventError } from "../../../src/extensible_events_v1/InvalidEventError";
+import { PollResponseEvent } from "../../../src/extensible_events_v1/PollResponseEvent";
+
+const SAMPLE_POLL = new PollStartEvent({
+    type: M_POLL_START.name,
+    content: {
+        [M_TEXT.name]: "FALLBACK Question here",
+        [M_POLL_START.name]: {
+            question: { [M_TEXT.name]: "Question here" },
+            kind: M_POLL_KIND_DISCLOSED.name,
+            max_selections: 2,
+            answers: [
+                { id: "one", [M_TEXT.name]: "ONE" },
+                { id: "two", [M_TEXT.name]: "TWO" },
+                { id: "thr", [M_TEXT.name]: "THR" },
+            ],
+        },
+    },
+});
+
+describe("PollResponseEvent", () => {
+    it("should parse a poll response", () => {
+        const input: IPartialEvent<PollResponseEventContent> = {
+            type: M_POLL_RESPONSE.name,
+            content: {
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                    event_id: "$poll",
+                },
+                [M_POLL_RESPONSE.name]: {
+                    answers: ["one"],
+                },
+            },
+        };
+        const response = new PollResponseEvent(input);
+        expect(response.spoiled).toBe(false);
+        expect(response.answerIds).toMatchObject(["one"]);
+        expect(response.pollEventId).toBe("$poll");
+    });
+
+    it("should fail to parse a missing relationship", () => {
+        const input: IPartialEvent<PollResponseEventContent> = {
+            type: M_POLL_RESPONSE.name,
+            content: {
+                [M_POLL_RESPONSE.name]: {
+                    answers: ["one"],
+                },
+            } as any, // force invalid type
+        };
+        expect(() => new PollResponseEvent(input)).toThrow(
+            new InvalidEventError("Relationship must be a reference to an event"),
+        );
+    });
+
+    it("should fail to parse a missing relationship event ID", () => {
+        const input: IPartialEvent<PollResponseEventContent> = {
+            type: M_POLL_RESPONSE.name,
+            content: {
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                },
+                [M_POLL_RESPONSE.name]: {
+                    answers: ["one"],
+                },
+            } as any, // force invalid type
+        };
+        expect(() => new PollResponseEvent(input)).toThrow(
+            new InvalidEventError("Relationship must be a reference to an event"),
+        );
+    });
+
+    it("should fail to parse an improper relationship", () => {
+        const input: IPartialEvent<PollResponseEventContent> = {
+            type: M_POLL_RESPONSE.name,
+            content: {
+                "m.relates_to": {
+                    rel_type: "org.example.not-relationship",
+                    event_id: "$poll",
+                },
+                [M_POLL_RESPONSE.name]: {
+                    answers: ["one"],
+                },
+            } as any, // force invalid type
+        };
+        expect(() => new PollResponseEvent(input)).toThrow(
+            new InvalidEventError("Relationship must be a reference to an event"),
+        );
+    });
+
+    describe("validateAgainst", () => {
+        it("should spoil the vote when no answers", () => {
+            const input: IPartialEvent<PollResponseEventContent> = {
+                type: M_POLL_RESPONSE.name,
+                content: {
+                    "m.relates_to": {
+                        rel_type: REFERENCE_RELATION.name,
+                        event_id: "$poll",
+                    },
+                    [M_POLL_RESPONSE.name]: {},
+                } as any, // force invalid type
+            };
+            const response = new PollResponseEvent(input);
+            expect(response.spoiled).toBe(true);
+
+            response.validateAgainst(SAMPLE_POLL);
+            expect(response.spoiled).toBe(true);
+        });
+
+        it("should spoil the vote when answers are empty", () => {
+            const input: IPartialEvent<PollResponseEventContent> = {
+                type: M_POLL_RESPONSE.name,
+                content: {
+                    "m.relates_to": {
+                        rel_type: REFERENCE_RELATION.name,
+                        event_id: "$poll",
+                    },
+                    [M_POLL_RESPONSE.name]: {
+                        answers: [],
+                    },
+                },
+            };
+            const response = new PollResponseEvent(input);
+            expect(response.spoiled).toBe(true);
+
+            response.validateAgainst(SAMPLE_POLL);
+            expect(response.spoiled).toBe(true);
+        });
+
+        it("should spoil the vote when answers are empty", () => {
+            const input: IPartialEvent<PollResponseEventContent> = {
+                type: M_POLL_RESPONSE.name,
+                content: {
+                    "m.relates_to": {
+                        rel_type: REFERENCE_RELATION.name,
+                        event_id: "$poll",
+                    },
+                    [M_POLL_RESPONSE.name]: {
+                        answers: [],
+                    },
+                },
+            };
+            const response = new PollResponseEvent(input);
+            expect(response.spoiled).toBe(true);
+
+            response.validateAgainst(SAMPLE_POLL);
+            expect(response.spoiled).toBe(true);
+        });
+
+        it("should spoil the vote when answers are not strings", () => {
+            const input: IPartialEvent<PollResponseEventContent> = {
+                type: M_POLL_RESPONSE.name,
+                content: {
+                    "m.relates_to": {
+                        rel_type: REFERENCE_RELATION.name,
+                        event_id: "$poll",
+                    },
+                    [M_POLL_RESPONSE.name]: {
+                        answers: [1, 2, 3],
+                    },
+                } as any, // force invalid type
+            };
+            const response = new PollResponseEvent(input);
+            expect(response.spoiled).toBe(true);
+
+            response.validateAgainst(SAMPLE_POLL);
+            expect(response.spoiled).toBe(true);
+        });
+
+        describe("consumer usage", () => {
+            it("should spoil the vote when invalid answers are given", () => {
+                const input: IPartialEvent<PollResponseEventContent> = {
+                    type: M_POLL_RESPONSE.name,
+                    content: {
+                        "m.relates_to": {
+                            rel_type: REFERENCE_RELATION.name,
+                            event_id: "$poll",
+                        },
+                        [M_POLL_RESPONSE.name]: {
+                            answers: ["A", "B", "C"],
+                        },
+                    },
+                };
+                const response = new PollResponseEvent(input);
+                expect(response.spoiled).toBe(false); // it won't know better
+
+                response.validateAgainst(SAMPLE_POLL);
+                expect(response.spoiled).toBe(true);
+            });
+
+            it("should truncate answers to the poll max selections", () => {
+                const input: IPartialEvent<PollResponseEventContent> = {
+                    type: M_POLL_RESPONSE.name,
+                    content: {
+                        "m.relates_to": {
+                            rel_type: REFERENCE_RELATION.name,
+                            event_id: "$poll",
+                        },
+                        [M_POLL_RESPONSE.name]: {
+                            answers: ["one", "two", "thr"],
+                        },
+                    },
+                };
+                const response = new PollResponseEvent(input);
+                expect(response.spoiled).toBe(false); // it won't know better
+                expect(response.answerIds).toMatchObject(["one", "two", "thr"]);
+
+                response.validateAgainst(SAMPLE_POLL);
+                expect(response.spoiled).toBe(false);
+                expect(response.answerIds).toMatchObject(["one", "two"]);
+            });
+        });
+    });
+
+    describe("from & serialize", () => {
+        it("should serialize to a poll response event", () => {
+            const response = PollResponseEvent.from(["A", "B", "C"], "$poll");
+            expect(response.spoiled).toBe(false);
+            expect(response.answerIds).toMatchObject(["A", "B", "C"]);
+            expect(response.pollEventId).toBe("$poll");
+
+            const serialized = response.serialize();
+            expect(M_POLL_RESPONSE.matches(serialized.type)).toBe(true);
+            expect(serialized.content).toMatchObject({
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                    event_id: "$poll",
+                },
+                [M_POLL_RESPONSE.name]: {
+                    answers: ["A", "B", "C"],
+                },
+            });
+        });
+
+        it("should serialize a spoiled vote", () => {
+            const response = PollResponseEvent.from([], "$poll");
+            expect(response.spoiled).toBe(true);
+            expect(response.answerIds).toMatchObject([]);
+            expect(response.pollEventId).toBe("$poll");
+
+            const serialized = response.serialize();
+            expect(M_POLL_RESPONSE.matches(serialized.type)).toBe(true);
+            expect(serialized.content).toMatchObject({
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                    event_id: "$poll",
+                },
+                [M_POLL_RESPONSE.name]: {
+                    answers: undefined,
+                },
+            });
+        });
+    });
+});

spec/unit/extensible_events_v1/PollStartEvent.spec.ts

@@ -0,0 +1,337 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { M_TEXT, IPartialEvent } from "../../../src/@types/extensible_events";
+import {
+    M_POLL_START,
+    M_POLL_KIND_DISCLOSED,
+    PollAnswer,
+    PollStartEventContent,
+    M_POLL_KIND_UNDISCLOSED,
+} from "../../../src/@types/polls";
+import { PollStartEvent, PollAnswerSubevent } from "../../../src/extensible_events_v1/PollStartEvent";
+import { InvalidEventError } from "../../../src/extensible_events_v1/InvalidEventError";
+
+describe("PollAnswerSubevent", () => {
+    // Note: throughout these tests we don't really bother testing that
+    // MessageEvent is doing its job. It has its own tests to worry about.
+
+    it("should parse an answer representation", () => {
+        const input: IPartialEvent<PollAnswer> = {
+            type: "org.matrix.sdk.poll.answer",
+            content: {
+                id: "one",
+                [M_TEXT.name]: "ONE",
+            },
+        };
+        const answer = new PollAnswerSubevent(input);
+        expect(answer.id).toBe("one");
+        expect(answer.text).toBe("ONE");
+    });
+
+    it("should fail to parse answers without an ID", () => {
+        const input: IPartialEvent<PollAnswer> = {
+            type: "org.matrix.sdk.poll.answer",
+            content: {
+                [M_TEXT.name]: "ONE",
+            } as any, // force invalid type
+        };
+        expect(() => new PollAnswerSubevent(input)).toThrow(
+            new InvalidEventError("Answer ID must be a non-empty string"),
+        );
+    });
+
+    it("should fail to parse answers without text", () => {
+        const input: IPartialEvent<PollAnswer> = {
+            type: "org.matrix.sdk.poll.answer",
+            content: {
+                id: "one",
+            } as any, // force invalid type
+        };
+        expect(() => new PollAnswerSubevent(input)).toThrow(); // we don't check message - that'll be MessageEvent's problem
+    });
+
+    describe("from & serialize", () => {
+        it("should serialize to a placeholder representation", () => {
+            const answer = PollAnswerSubevent.from("one", "ONE");
+            expect(answer.id).toBe("one");
+            expect(answer.text).toBe("ONE");
+
+            const serialized = answer.serialize();
+            expect(serialized.type).toBe("org.matrix.sdk.poll.answer");
+            expect(serialized.content).toMatchObject({
+                id: "one",
+                [M_TEXT.name]: expect.any(String), // tested by MessageEvent
+            });
+        });
+    });
+});
+
+describe("PollStartEvent", () => {
+    // Note: throughout these tests we don't really bother testing that
+    // MessageEvent is doing its job. It has its own tests to worry about.
+
+    it("should parse a poll", () => {
+        const input: IPartialEvent<PollStartEventContent> = {
+            type: M_POLL_START.name,
+            content: {
+                [M_TEXT.name]: "FALLBACK Question here",
+                [M_POLL_START.name]: {
+                    question: { [M_TEXT.name]: "Question here" },
+                    kind: M_POLL_KIND_DISCLOSED.name,
+                    max_selections: 2,
+                    answers: [
+                        { id: "one", [M_TEXT.name]: "ONE" },
+                        { id: "two", [M_TEXT.name]: "TWO" },
+                        { id: "thr", [M_TEXT.name]: "THR" },
+                    ],
+                },
+            },
+        };
+        const poll = new PollStartEvent(input);
+        expect(poll.question).toBeDefined();
+        expect(poll.question.text).toBe("Question here");
+        expect(poll.kind).toBe(M_POLL_KIND_DISCLOSED);
+        expect(M_POLL_KIND_DISCLOSED.matches(poll.rawKind)).toBe(true);
+        expect(poll.maxSelections).toBe(2);
+        expect(poll.answers.length).toBe(3);
+        expect(poll.answers.some((a) => a.id === "one" && a.text === "ONE")).toBe(true);
+        expect(poll.answers.some((a) => a.id === "two" && a.text === "TWO")).toBe(true);
+        expect(poll.answers.some((a) => a.id === "thr" && a.text === "THR")).toBe(true);
+    });
+
+    it("should fail to parse a missing question", () => {
+        const input: IPartialEvent<PollStartEventContent> = {
+            type: M_POLL_START.name,
+            content: {
+                [M_TEXT.name]: "FALLBACK Question here",
+                [M_POLL_START.name]: {
+                    kind: M_POLL_KIND_DISCLOSED.name,
+                    max_selections: 2,
+                    answers: [
+                        { id: "one", [M_TEXT.name]: "ONE" },
+                        { id: "two", [M_TEXT.name]: "TWO" },
+                        { id: "thr", [M_TEXT.name]: "THR" },
+                    ],
+                },
+            } as any, // force invalid type
+        };
+        expect(() => new PollStartEvent(input)).toThrow(new InvalidEventError("A question is required"));
+    });
+
+    it("should fail to parse non-array answers", () => {
+        const input: IPartialEvent<PollStartEventContent> = {
+            type: M_POLL_START.name,
+            content: {
+                [M_TEXT.name]: "FALLBACK Question here",
+                [M_POLL_START.name]: {
+                    question: { [M_TEXT.name]: "Question here" },
+                    kind: M_POLL_KIND_DISCLOSED.name,
+                    max_selections: 2,
+                    answers: "one",
+                } as any, // force invalid type
+            },
+        };
+        expect(() => new PollStartEvent(input)).toThrow(new InvalidEventError("Poll answers must be an array"));
+    });
+
+    it("should fail to parse invalid answers", () => {
+        const input: IPartialEvent<PollStartEventContent> = {
+            type: M_POLL_START.name,
+            content: {
+                [M_TEXT.name]: "FALLBACK Question here",
+                [M_POLL_START.name]: {
+                    question: { [M_TEXT.name]: "Question here" },
+                    kind: M_POLL_KIND_DISCLOSED.name,
+                    max_selections: 2,
+                    answers: [{ id: "one" }, { [M_TEXT.name]: "TWO" }],
+                } as any, // force invalid type
+            },
+        };
+        expect(() => new PollStartEvent(input)).toThrow(); // error tested by PollAnswerSubevent tests
+    });
+
+    it("should fail to parse lack of answers", () => {
+        const input: IPartialEvent<PollStartEventContent> = {
+            type: M_POLL_START.name,
+            content: {
+                [M_TEXT.name]: "FALLBACK Question here",
+                [M_POLL_START.name]: {
+                    question: { [M_TEXT.name]: "Question here" },
+                    kind: M_POLL_KIND_DISCLOSED.name,
+                    max_selections: 2,
+                    answers: [],
+                } as any, // force invalid type
+            },
+        };
+        expect(() => new PollStartEvent(input)).toThrow(new InvalidEventError("No answers available"));
+    });
+
+    it("should truncate answers at 20", () => {
+        const input: IPartialEvent<PollStartEventContent> = {
+            type: M_POLL_START.name,
+            content: {
+                [M_TEXT.name]: "FALLBACK Question here",
+                [M_POLL_START.name]: {
+                    question: { [M_TEXT.name]: "Question here" },
+                    kind: M_POLL_KIND_DISCLOSED.name,
+                    max_selections: 2,
+                    answers: [
+                        { id: "01", [M_TEXT.name]: "A" },
+                        { id: "02", [M_TEXT.name]: "B" },
+                        { id: "03", [M_TEXT.name]: "C" },
+                        { id: "04", [M_TEXT.name]: "D" },
+                        { id: "05", [M_TEXT.name]: "E" },
+                        { id: "06", [M_TEXT.name]: "F" },
+                        { id: "07", [M_TEXT.name]: "G" },
+                        { id: "08", [M_TEXT.name]: "H" },
+                        { id: "09", [M_TEXT.name]: "I" },
+                        { id: "10", [M_TEXT.name]: "J" },
+                        { id: "11", [M_TEXT.name]: "K" },
+                        { id: "12", [M_TEXT.name]: "L" },
+                        { id: "13", [M_TEXT.name]: "M" },
+                        { id: "14", [M_TEXT.name]: "N" },
+                        { id: "15", [M_TEXT.name]: "O" },
+                        { id: "16", [M_TEXT.name]: "P" },
+                        { id: "17", [M_TEXT.name]: "Q" },
+                        { id: "18", [M_TEXT.name]: "R" },
+                        { id: "19", [M_TEXT.name]: "S" },
+                        { id: "20", [M_TEXT.name]: "T" },
+                        { id: "FAIL", [M_TEXT.name]: "U" },
+                    ],
+                },
+            },
+        };
+        const poll = new PollStartEvent(input);
+        expect(poll.answers.length).toBe(20);
+        expect(poll.answers.some((a) => a.id === "FAIL")).toBe(false);
+    });
+
+    it("should infer a kind from unknown kinds", () => {
+        const input: IPartialEvent<PollStartEventContent> = {
+            type: M_POLL_START.name,
+            content: {
+                [M_TEXT.name]: "FALLBACK Question here",
+                [M_POLL_START.name]: {
+                    question: { [M_TEXT.name]: "Question here" },
+                    kind: "org.example.custom.poll.kind",
+                    max_selections: 2,
+                    answers: [
+                        { id: "01", [M_TEXT.name]: "A" },
+                        { id: "02", [M_TEXT.name]: "B" },
+                        { id: "03", [M_TEXT.name]: "C" },
+                    ],
+                },
+            },
+        };
+        const poll = new PollStartEvent(input);
+        expect(poll.kind).toBe(M_POLL_KIND_UNDISCLOSED);
+        expect(poll.rawKind).toBe("org.example.custom.poll.kind");
+    });
+
+    it("should infer a kind from missing kinds", () => {
+        const input: IPartialEvent<PollStartEventContent> = {
+            type: M_POLL_START.name,
+            content: {
+                [M_TEXT.name]: "FALLBACK Question here",
+                [M_POLL_START.name]: {
+                    question: { [M_TEXT.name]: "Question here" },
+                    max_selections: 2,
+                    answers: [
+                        { id: "01", [M_TEXT.name]: "A" },
+                        { id: "02", [M_TEXT.name]: "B" },
+                        { id: "03", [M_TEXT.name]: "C" },
+                    ],
+                } as any, // force invalid type
+            },
+        };
+        const poll = new PollStartEvent(input);
+        expect(poll.kind).toBe(M_POLL_KIND_UNDISCLOSED);
+        expect(poll.rawKind).toBeFalsy();
+    });
+
+    describe("from & serialize", () => {
+        it("should serialize to a poll start event", () => {
+            const poll = PollStartEvent.from("Question here", ["A", "B", "C"], M_POLL_KIND_DISCLOSED, 2);
+            expect(poll.question.text).toBe("Question here");
+            expect(poll.kind).toBe(M_POLL_KIND_DISCLOSED);
+            expect(M_POLL_KIND_DISCLOSED.matches(poll.rawKind)).toBe(true);
+            expect(poll.maxSelections).toBe(2);
+            expect(poll.answers.length).toBe(3);
+            expect(poll.answers.some((a) => a.text === "A")).toBe(true);
+            expect(poll.answers.some((a) => a.text === "B")).toBe(true);
+            expect(poll.answers.some((a) => a.text === "C")).toBe(true);
+
+            // Ids are non-empty and unique
+            expect(poll.answers[0].id).toHaveLength(16);
+            expect(poll.answers[1].id).toHaveLength(16);
+            expect(poll.answers[2].id).toHaveLength(16);
+            expect(poll.answers[0].id).not.toEqual(poll.answers[1].id);
+            expect(poll.answers[0].id).not.toEqual(poll.answers[2].id);
+            expect(poll.answers[1].id).not.toEqual(poll.answers[2].id);
+
+            const serialized = poll.serialize();
+            expect(M_POLL_START.matches(serialized.type)).toBe(true);
+            expect(serialized.content).toMatchObject({
+                [M_TEXT.name]: "Question here\n1. A\n2. B\n3. C",
+                [M_POLL_START.name]: {
+                    question: {
+                        [M_TEXT.name]: expect.any(String), // tested by MessageEvent tests
+                    },
+                    kind: M_POLL_KIND_DISCLOSED.name,
+                    max_selections: 2,
+                    answers: [
+                        // M_TEXT tested by MessageEvent tests
+                        { id: expect.any(String), [M_TEXT.name]: expect.any(String) },
+                        { id: expect.any(String), [M_TEXT.name]: expect.any(String) },
+                        { id: expect.any(String), [M_TEXT.name]: expect.any(String) },
+                    ],
+                },
+            });
+        });
+
+        it("should serialize to a custom kind poll start event", () => {
+            const poll = PollStartEvent.from("Question here", ["A", "B", "C"], "org.example.poll.kind", 2);
+            expect(poll.question.text).toBe("Question here");
+            expect(poll.kind).toBe(M_POLL_KIND_UNDISCLOSED);
+            expect(poll.rawKind).toBe("org.example.poll.kind");
+            expect(poll.maxSelections).toBe(2);
+            expect(poll.answers.length).toBe(3);
+            expect(poll.answers.some((a) => a.text === "A")).toBe(true);
+            expect(poll.answers.some((a) => a.text === "B")).toBe(true);
+            expect(poll.answers.some((a) => a.text === "C")).toBe(true);
+
+            const serialized = poll.serialize();
+            expect(M_POLL_START.matches(serialized.type)).toBe(true);
+            expect(serialized.content).toMatchObject({
+                [M_TEXT.name]: "Question here\n1. A\n2. B\n3. C",
+                [M_POLL_START.name]: {
+                    question: {
+                        [M_TEXT.name]: expect.any(String), // tested by MessageEvent tests
+                    },
+                    kind: "org.example.poll.kind",
+                    max_selections: 2,
+                    answers: [
+                        // M_MESSAGE tested by MessageEvent tests
+                        { id: expect.any(String), [M_TEXT.name]: expect.any(String) },
+                        { id: expect.any(String), [M_TEXT.name]: expect.any(String) },
+                        { id: expect.any(String), [M_TEXT.name]: expect.any(String) },
+                    ],
+                },
+            });
+        });
+    });
+});

spec/unit/extensible_events_v1/utilities.spec.ts

@@ -0,0 +1,87 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { NamespacedValue } from "matrix-events-sdk";
+
+import { isEventTypeSame } from "../../../src/@types/extensible_events";
+
+describe("isEventTypeSame", () => {
+    it("should match string and string", () => {
+        const a = "org.example.message-like";
+        const b = "org.example.different";
+
+        expect(isEventTypeSame(a, b)).toBe(false);
+        expect(isEventTypeSame(b, a)).toBe(false);
+
+        expect(isEventTypeSame(a, a)).toBe(true);
+        expect(isEventTypeSame(b, b)).toBe(true);
+    });
+
+    it("should match string and namespace", () => {
+        const a = "org.example.message-like";
+        const b = new NamespacedValue<string, string>("org.example.stable", "org.example.unstable");
+
+        expect(isEventTypeSame(a, b)).toBe(false);
+        expect(isEventTypeSame(b, a)).toBe(false);
+
+        expect(isEventTypeSame(a, a)).toBe(true);
+        expect(isEventTypeSame(b, b)).toBe(true);
+        expect(isEventTypeSame(b.name, b)).toBe(true);
+        expect(isEventTypeSame(b.altName, b)).toBe(true);
+        expect(isEventTypeSame(b, b.name)).toBe(true);
+        expect(isEventTypeSame(b, b.altName)).toBe(true);
+    });
+
+    it("should match namespace and namespace", () => {
+        const a = new NamespacedValue<string, string>("org.example.stable1", "org.example.unstable1");
+        const b = new NamespacedValue<string, string>("org.example.stable2", "org.example.unstable2");
+
+        expect(isEventTypeSame(a, b)).toBe(false);
+        expect(isEventTypeSame(b, a)).toBe(false);
+
+        expect(isEventTypeSame(a, a)).toBe(true);
+        expect(isEventTypeSame(a.name, a)).toBe(true);
+        expect(isEventTypeSame(a.altName, a)).toBe(true);
+        expect(isEventTypeSame(a, a.name)).toBe(true);
+        expect(isEventTypeSame(a, a.altName)).toBe(true);
+
+        expect(isEventTypeSame(b, b)).toBe(true);
+        expect(isEventTypeSame(b.name, b)).toBe(true);
+        expect(isEventTypeSame(b.altName, b)).toBe(true);
+        expect(isEventTypeSame(b, b.name)).toBe(true);
+        expect(isEventTypeSame(b, b.altName)).toBe(true);
+    });
+
+    it("should match namespaces of different pointers", () => {
+        const a = new NamespacedValue<string, string>("org.example.stable", "org.example.unstable");
+        const b = new NamespacedValue<string, string>("org.example.stable", "org.example.unstable");
+
+        expect(isEventTypeSame(a, b)).toBe(true);
+        expect(isEventTypeSame(b, a)).toBe(true);
+
+        expect(isEventTypeSame(a, a)).toBe(true);
+        expect(isEventTypeSame(a.name, a)).toBe(true);
+        expect(isEventTypeSame(a.altName, a)).toBe(true);
+        expect(isEventTypeSame(a, a.name)).toBe(true);
+        expect(isEventTypeSame(a, a.altName)).toBe(true);
+
+        expect(isEventTypeSame(b, b)).toBe(true);
+        expect(isEventTypeSame(b.name, b)).toBe(true);
+        expect(isEventTypeSame(b.altName, b)).toBe(true);
+        expect(isEventTypeSame(b, b.name)).toBe(true);
+        expect(isEventTypeSame(b, b.altName)).toBe(true);
+    });
+});

spec/unit/location.spec.ts

@@ -22,7 +22,7 @@ import {
     M_TIMESTAMP,
     LocationEventWireContent,
 } from "../../src/@types/location";
-import { TEXT_NODE_TYPE } from "../../src/@types/extensible_events";
+import { M_TEXT } from "../../src/@types/extensible_events";
 import { MsgType } from "../../src/@types/event";
 
 describe("Location", function () {
@@ -32,7 +32,7 @@ describe("Location", function () {
         geo_uri: "geo:-36.24484561954707,175.46884959563613;u=10",
         [M_LOCATION.name]: { uri: "geo:-36.24484561954707,175.46884959563613;u=10", description: null },
         [M_ASSET.name]: { type: "m.self" },
-        [TEXT_NODE_TYPE.name]: "Location geo:-36.24484561954707,175.46884959563613;u=10 at 2022-03-09T11:01:52.443Z",
+        [M_TEXT.name]: "Location geo:-36.24484561954707,175.46884959563613;u=10 at 2022-03-09T11:01:52.443Z",
         [M_TIMESTAMP.name]: 1646823712443,
     } as any;
 
@@ -59,7 +59,7 @@ describe("Location", function () {
             description: undefined,
         });
         expect(M_ASSET.findIn(loc)).toEqual({ type: LocationAssetType.Self });
-        expect(TEXT_NODE_TYPE.findIn(loc)).toEqual("User Location geo:foo at 1970-01-02T13:17:15.435Z");
+        expect(M_TEXT.findIn(loc)).toEqual("User Location geo:foo at 1970-01-02T13:17:15.435Z");
         expect(M_TIMESTAMP.findIn(loc)).toEqual(134235435);
     });
 
@@ -74,7 +74,7 @@ describe("Location", function () {
             description: "desc",
         });
         expect(M_ASSET.findIn(loc)).toEqual({ type: LocationAssetType.Pin });
-        expect(TEXT_NODE_TYPE.findIn(loc)).toEqual('Location "desc" geo:bar at 1970-01-02T13:17:15.436Z');
+        expect(M_TEXT.findIn(loc)).toEqual('Location "desc" geo:bar at 1970-01-02T13:17:15.436Z');
         expect(M_TIMESTAMP.findIn(loc)).toEqual(134235436);
     });
 

spec/unit/matrix-client.spec.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2022 The Matrix.org Foundation C.I.C.
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -17,7 +17,7 @@ limitations under the License.
 import { mocked } from "jest-mock";
 
 import { logger } from "../../src/logger";
-import { ClientEvent, ITurnServerResponse, MatrixClient, Store } from "../../src/client";
+import { ClientEvent, IMatrixClientCreateOpts, ITurnServerResponse, MatrixClient, Store } from "../../src/client";
 import { Filter } from "../../src/filter";
 import { DEFAULT_TREE_POWER_LEVELS_TEMPLATE } from "../../src/models/MSC3089TreeSpace";
 import {
@@ -276,7 +276,7 @@ describe("MatrixClient", function () {
         );
     }
 
-    function makeClient() {
+    function makeClient(opts?: Partial<IMatrixClientCreateOpts>) {
         client = new MatrixClient({
             baseUrl: "https://my.home.server",
             idBaseUrl: identityServerUrl,
@@ -285,6 +285,7 @@ describe("MatrixClient", function () {
             store: store,
             scheduler: scheduler,
             userId: userId,
+            ...(opts || {}),
         });
         // FIXME: We shouldn't be yanking http like this.
         client.http = (["authedRequest", "getContentUri", "request", "uploadContent"] as const).reduce((r, k) => {
@@ -1414,7 +1415,7 @@ describe("MatrixClient", function () {
                 expect(getRoomId).toEqual(roomId);
                 return mockRoom;
             };
-            client.crypto = {
+            client.crypto = client["cryptoBackend"] = {
                 // mock crypto
                 encryptEvent: () => new Promise(() => {}),
                 stop: jest.fn(),
@@ -1436,8 +1437,9 @@ describe("MatrixClient", function () {
 
         it("should cancel an event which is encrypting", async () => {
             // @ts-ignore protected method access
-            client.encryptAndSendEvent(null, event);
+            client.encryptAndSendEvent(mockRoom, event);
             await testUtils.emitPromise(event, "Event.status");
+            expect(event.status).toBe(EventStatus.ENCRYPTING);
             client.cancelPendingEvent(event);
             assertCancelled();
         });
@@ -1456,9 +1458,20 @@ describe("MatrixClient", function () {
     });
 
     describe("threads", () => {
+        it.each([
+            { startOpts: {}, hasThreadSupport: false },
+            { startOpts: { threadSupport: true }, hasThreadSupport: true },
+            { startOpts: { threadSupport: false }, hasThreadSupport: false },
+            { startOpts: { experimentalThreadSupport: true }, hasThreadSupport: true },
+            { startOpts: { experimentalThreadSupport: true, threadSupport: false }, hasThreadSupport: false },
+        ])("enabled thread support for the SDK instance ", async ({ startOpts, hasThreadSupport }) => {
+            await client.startClient(startOpts);
+            expect(client.supportsThreads()).toBe(hasThreadSupport);
+        });
+
         it("partitions root events to room timeline and thread timeline", () => {
-            const supportsExperimentalThreads = client.supportsExperimentalThreads;
-            client.supportsExperimentalThreads = () => true;
+            const supportsThreads = client.supportsThreads;
+            client.supportsThreads = () => true;
             const room = new Room("!room1:matrix.org", client, userId);
 
             const rootEvent = new MatrixEvent({
@@ -1487,7 +1500,7 @@ describe("MatrixClient", function () {
             expect(threadEvents).toHaveLength(1);
 
             // Restore method
-            client.supportsExperimentalThreads = supportsExperimentalThreads;
+            client.supportsThreads = supportsThreads;
         });
     });
 
@@ -2198,14 +2211,14 @@ describe("MatrixClient", function () {
         });
     });
 
-    describe("getVisibleRooms", () => {
+    describe("room lists and history", () => {
         function roomCreateEvent(newRoomId: string, predecessorRoomId: string): MatrixEvent {
             return new MatrixEvent({
                 content: {
                     "creator": "@daryl:alexandria.example.com",
                     "m.federate": true,
                     "predecessor": {
-                        event_id: "spec_is_not_clear_what_id_this_is",
+                        event_id: "id_of_last_event",
                         room_id: predecessorRoomId,
                     },
                     "room_version": "9",
@@ -2234,45 +2247,442 @@ describe("MatrixClient", function () {
             });
         }
 
-        it("Returns an empty list if there are no rooms", () => {
-            client.store = new StubStore();
-            client.store.getRooms = () => [];
-            const rooms = client.getVisibleRooms();
-            expect(rooms).toHaveLength(0);
+        function predecessorEvent(newRoomId: string, predecessorRoomId: string): MatrixEvent {
+            return new MatrixEvent({
+                content: {
+                    predecessor_room_id: predecessorRoomId,
+                },
+                event_id: `predecessor_event_id_pred_${predecessorRoomId}`,
+                origin_server_ts: 1432735824653,
+                room_id: newRoomId,
+                sender: "@daryl:alexandria.example.com",
+                state_key: "",
+                type: "org.matrix.msc3946.room_predecessor",
+            });
+        }
+
+        describe("getVisibleRooms", () => {
+            function setUpReplacedRooms(): {
+                room1: Room;
+                room2: Room;
+                replacedByCreate1: Room;
+                replacedByCreate2: Room;
+                replacedByDynamicPredecessor1: Room;
+                replacedByDynamicPredecessor2: Room;
+            } {
+                const room1 = new Room("room1", client, "@carol:alexandria.example.com");
+                const replacedByCreate1 = new Room("replacedByCreate1", client, "@carol:alexandria.example.com");
+                const replacedByCreate2 = new Room("replacedByCreate2", client, "@carol:alexandria.example.com");
+                const replacedByDynamicPredecessor1 = new Room("dyn1", client, "@carol:alexandria.example.com");
+                const replacedByDynamicPredecessor2 = new Room("dyn2", client, "@carol:alexandria.example.com");
+                const room2 = new Room("room2", client, "@daryl:alexandria.example.com");
+                client.store = new StubStore();
+                client.store.getRooms = () => [
+                    room1,
+                    replacedByCreate1,
+                    replacedByCreate2,
+                    replacedByDynamicPredecessor1,
+                    replacedByDynamicPredecessor2,
+                    room2,
+                ];
+                room1.addLiveEvents(
+                    [
+                        roomCreateEvent(room1.roomId, replacedByCreate1.roomId),
+                        predecessorEvent(room1.roomId, replacedByDynamicPredecessor1.roomId),
+                    ],
+                    {},
+                );
+                room2.addLiveEvents(
+                    [
+                        roomCreateEvent(room2.roomId, replacedByCreate2.roomId),
+                        predecessorEvent(room2.roomId, replacedByDynamicPredecessor2.roomId),
+                    ],
+                    {},
+                );
+                replacedByCreate1.addLiveEvents([tombstoneEvent(room1.roomId, replacedByCreate1.roomId)], {});
+                replacedByCreate2.addLiveEvents([tombstoneEvent(room2.roomId, replacedByCreate2.roomId)], {});
+                replacedByDynamicPredecessor1.addLiveEvents(
+                    [tombstoneEvent(room1.roomId, replacedByDynamicPredecessor1.roomId)],
+                    {},
+                );
+                replacedByDynamicPredecessor2.addLiveEvents(
+                    [tombstoneEvent(room2.roomId, replacedByDynamicPredecessor2.roomId)],
+                    {},
+                );
+
+                return {
+                    room1,
+                    room2,
+                    replacedByCreate1,
+                    replacedByCreate2,
+                    replacedByDynamicPredecessor1,
+                    replacedByDynamicPredecessor2,
+                };
+            }
+            it("Returns an empty list if there are no rooms", () => {
+                client.store = new StubStore();
+                client.store.getRooms = () => [];
+                const rooms = client.getVisibleRooms();
+                expect(rooms).toHaveLength(0);
+            });
+
+            it("Returns all non-replaced rooms", () => {
+                const room1 = new Room("room1", client, "@carol:alexandria.example.com");
+                const room2 = new Room("room2", client, "@daryl:alexandria.example.com");
+                client.store = new StubStore();
+                client.store.getRooms = () => [room1, room2];
+                const rooms = client.getVisibleRooms();
+                expect(rooms).toContain(room1);
+                expect(rooms).toContain(room2);
+                expect(rooms).toHaveLength(2);
+            });
+
+            it("Does not return replaced rooms", () => {
+                // Given 4 rooms, 2 of which have been replaced
+                const room1 = new Room("room1", client, "@carol:alexandria.example.com");
+                const replacedRoom1 = new Room("replacedRoom1", client, "@carol:alexandria.example.com");
+                const replacedRoom2 = new Room("replacedRoom2", client, "@carol:alexandria.example.com");
+                const room2 = new Room("room2", client, "@daryl:alexandria.example.com");
+                client.store = new StubStore();
+                client.store.getRooms = () => [room1, replacedRoom1, replacedRoom2, room2];
+                room1.addLiveEvents([roomCreateEvent(room1.roomId, replacedRoom1.roomId)], {});
+                room2.addLiveEvents([roomCreateEvent(room2.roomId, replacedRoom2.roomId)], {});
+                replacedRoom1.addLiveEvents([tombstoneEvent(room1.roomId, replacedRoom1.roomId)], {});
+                replacedRoom2.addLiveEvents([tombstoneEvent(room2.roomId, replacedRoom2.roomId)], {});
+
+                // When we ask for the visible rooms
+                const rooms = client.getVisibleRooms();
+
+                // Then we only get the ones that have not been replaced
+                expect(rooms).not.toContain(replacedRoom1);
+                expect(rooms).not.toContain(replacedRoom2);
+                expect(rooms).toContain(room1);
+                expect(rooms).toContain(room2);
+            });
+
+            it("Ignores m.predecessor if we don't ask to use it", () => {
+                // Given 6 rooms, 2 of which have been replaced, and 2 of which WERE
+                // replaced by create events, but are now NOT replaced, because an
+                // m.predecessor event has changed the room's predecessor.
+                const {
+                    room1,
+                    room2,
+                    replacedByCreate1,
+                    replacedByCreate2,
+                    replacedByDynamicPredecessor1,
+                    replacedByDynamicPredecessor2,
+                } = setUpReplacedRooms();
+
+                // When we ask for the visible rooms
+                const rooms = client.getVisibleRooms(); // Don't supply msc3946ProcessDynamicPredecessor
+
+                // Then we only get the ones that have not been replaced
+                expect(rooms).not.toContain(replacedByCreate1);
+                expect(rooms).not.toContain(replacedByCreate2);
+                expect(rooms).toContain(replacedByDynamicPredecessor1);
+                expect(rooms).toContain(replacedByDynamicPredecessor2);
+                expect(rooms).toContain(room1);
+                expect(rooms).toContain(room2);
+            });
+
+            it("Considers rooms replaced with m.predecessor events to be replaced", () => {
+                // Given 6 rooms, 2 of which have been replaced, and 2 of which WERE
+                // replaced by create events, but are now NOT replaced, because an
+                // m.predecessor event has changed the room's predecessor.
+                const {
+                    room1,
+                    room2,
+                    replacedByCreate1,
+                    replacedByCreate2,
+                    replacedByDynamicPredecessor1,
+                    replacedByDynamicPredecessor2,
+                } = setUpReplacedRooms();
+
+                // When we ask for the visible rooms
+                const useMsc3946 = true;
+                const rooms = client.getVisibleRooms(useMsc3946);
+
+                // Then we only get the ones that have not been replaced
+                expect(rooms).not.toContain(replacedByDynamicPredecessor1);
+                expect(rooms).not.toContain(replacedByDynamicPredecessor2);
+                expect(rooms).toContain(replacedByCreate1);
+                expect(rooms).toContain(replacedByCreate2);
+                expect(rooms).toContain(room1);
+                expect(rooms).toContain(room2);
+            });
+
+            it("Ignores m.predecessor if we don't ask to use it", () => {
+                // Given 6 rooms, 2 of which have been replaced, and 2 of which WERE
+                // replaced by create events, but are now NOT replaced, because an
+                // m.predecessor event has changed the room's predecessor.
+                const {
+                    room1,
+                    room2,
+                    replacedByCreate1,
+                    replacedByCreate2,
+                    replacedByDynamicPredecessor1,
+                    replacedByDynamicPredecessor2,
+                } = setUpReplacedRooms();
+
+                // When we ask for the visible rooms
+                const rooms = client.getVisibleRooms(); // Don't supply msc3946ProcessDynamicPredecessor
+
+                // Then we only get the ones that have not been replaced
+                expect(rooms).not.toContain(replacedByCreate1);
+                expect(rooms).not.toContain(replacedByCreate2);
+                expect(rooms).toContain(replacedByDynamicPredecessor1);
+                expect(rooms).toContain(replacedByDynamicPredecessor2);
+                expect(rooms).toContain(room1);
+                expect(rooms).toContain(room2);
+            });
         });
 
-        it("Returns all non-replaced rooms", () => {
-            const room1 = new Room("room1", client, "@carol:alexandria.example.com");
-            const room2 = new Room("room2", client, "@daryl:alexandria.example.com");
-            client.store = new StubStore();
-            client.store.getRooms = () => [room1, room2];
-            const rooms = client.getVisibleRooms();
-            expect(rooms).toContain(room1);
-            expect(rooms).toContain(room2);
-            expect(rooms).toHaveLength(2);
-        });
+        describe("getRoomUpgradeHistory", () => {
+            /**
+             * Create a chain of room history with create events and tombstones.
+             *
+             * @param creates include create events (default=true)
+             * @param tombstones include tomstone events (default=true)
+             * @returns 4 rooms chained together with tombstones and create
+             *          events, in order from oldest to latest.
+             */
+            function createRoomHistory(creates = true, tombstones = true): [Room, Room, Room, Room] {
+                const room1 = new Room("room1", client, "@carol:alexandria.example.com");
+                const room2 = new Room("room2", client, "@daryl:alexandria.example.com");
+                const room3 = new Room("room3", client, "@rick:helicopter.example.com");
+                const room4 = new Room("room4", client, "@michonne:hawthorne.example.com");
 
-        it("Does not return replaced rooms", () => {
-            // Given 4 rooms, 2 of which have been replaced
-            const room1 = new Room("room1", client, "@carol:alexandria.example.com");
-            const replacedRoom1 = new Room("replacedRoom1", client, "@carol:alexandria.example.com");
-            const replacedRoom2 = new Room("replacedRoom2", client, "@carol:alexandria.example.com");
-            const room2 = new Room("room2", client, "@daryl:alexandria.example.com");
-            client.store = new StubStore();
-            client.store.getRooms = () => [room1, replacedRoom1, replacedRoom2, room2];
-            room1.addLiveEvents([roomCreateEvent(room1.roomId, replacedRoom1.roomId)], {});
-            room2.addLiveEvents([roomCreateEvent(room2.roomId, replacedRoom2.roomId)], {});
-            replacedRoom1.addLiveEvents([tombstoneEvent(room1.roomId, replacedRoom1.roomId)], {});
-            replacedRoom2.addLiveEvents([tombstoneEvent(room2.roomId, replacedRoom2.roomId)], {});
+                if (creates) {
+                    room2.addLiveEvents([roomCreateEvent(room2.roomId, room1.roomId)]);
+                    room3.addLiveEvents([roomCreateEvent(room3.roomId, room2.roomId)]);
+                    room4.addLiveEvents([roomCreateEvent(room4.roomId, room3.roomId)]);
+                }
 
-            // When we ask for the visible rooms
-            const rooms = client.getVisibleRooms();
+                if (tombstones) {
+                    room1.addLiveEvents([tombstoneEvent(room2.roomId, room1.roomId)], {});
+                    room2.addLiveEvents([tombstoneEvent(room3.roomId, room2.roomId)], {});
+                    room3.addLiveEvents([tombstoneEvent(room4.roomId, room3.roomId)], {});
+                }
 
-            // Then we only get the ones that have not been replaced
-            expect(rooms).not.toContain(replacedRoom1);
-            expect(rooms).not.toContain(replacedRoom2);
-            expect(rooms).toContain(room1);
-            expect(rooms).toContain(room2);
+                mocked(store.getRoom).mockImplementation((roomId: string) => {
+                    return { room1, room2, room3, room4 }[roomId] || null;
+                });
+
+                return [room1, room2, room3, room4];
+            }
+
+            /**
+             * Creates 2 alternate chains of room history: one using create
+             * events, and one using MSC2946 predecessor+tombstone events.
+             *
+             * Using create, history looks like:
+             * room1->room2->room3->room4 (but note we do not create tombstones)
+             *
+             * Using predecessor+tombstone, history looks like:
+             * dynRoom1->dynRoom2->room3->dynRoom4->dynRoom4
+             *
+             * @returns [room1, room2, room3, room4, dynRoom1, dynRoom2,
+             *          dynRoom4, dynRoom5].
+             */
+            function createDynamicRoomHistory(): [Room, Room, Room, Room, Room, Room, Room, Room] {
+                // Don't create tombstones for the old versions - we generally
+                // expect only one tombstone in a room, and we are confused by
+                // anything else.
+                const creates = true;
+                const tombstones = false;
+                const [room1, room2, room3, room4] = createRoomHistory(creates, tombstones);
+                const dynRoom1 = new Room("dynRoom1", client, "@rick:grimes.example.com");
+                const dynRoom2 = new Room("dynRoom2", client, "@rick:grimes.example.com");
+                const dynRoom4 = new Room("dynRoom4", client, "@rick:grimes.example.com");
+                const dynRoom5 = new Room("dynRoom5", client, "@rick:grimes.example.com");
+
+                dynRoom1.addLiveEvents([tombstoneEvent(dynRoom2.roomId, dynRoom1.roomId)], {});
+                dynRoom2.addLiveEvents([predecessorEvent(dynRoom2.roomId, dynRoom1.roomId)]);
+
+                dynRoom2.addLiveEvents([tombstoneEvent(room3.roomId, dynRoom2.roomId)], {});
+                room3.addLiveEvents([predecessorEvent(room3.roomId, dynRoom2.roomId)]);
+
+                room3.addLiveEvents([tombstoneEvent(dynRoom4.roomId, room3.roomId)], {});
+                dynRoom4.addLiveEvents([predecessorEvent(dynRoom4.roomId, room3.roomId)]);
+
+                dynRoom4.addLiveEvents([tombstoneEvent(dynRoom5.roomId, dynRoom4.roomId)], {});
+                dynRoom5.addLiveEvents([predecessorEvent(dynRoom5.roomId, dynRoom4.roomId)]);
+
+                mocked(store.getRoom)
+                    .mockClear()
+                    .mockImplementation((roomId: string) => {
+                        return { room1, room2, room3, room4, dynRoom1, dynRoom2, dynRoom4, dynRoom5 }[roomId] || null;
+                    });
+
+                return [room1, room2, room3, room4, dynRoom1, dynRoom2, dynRoom4, dynRoom5];
+            }
+
+            it("Returns an empty list if room does not exist", () => {
+                const history = client.getRoomUpgradeHistory("roomthatdoesnotexist");
+                expect(history).toHaveLength(0);
+            });
+
+            it("Returns just this room if there is no predecessor", () => {
+                const mainRoom = new Room("mainRoom", client, "@carol:alexandria.example.com");
+                mocked(store.getRoom).mockReturnValue(mainRoom);
+                const history = client.getRoomUpgradeHistory(mainRoom.roomId);
+                expect(history).toEqual([mainRoom]);
+            });
+
+            it("Returns the predecessors of this room", () => {
+                const [room1, room2, room3, room4] = createRoomHistory();
+                const history = client.getRoomUpgradeHistory(room4.roomId);
+                expect(history.map((room) => room.roomId)).toEqual([
+                    room1.roomId,
+                    room2.roomId,
+                    room3.roomId,
+                    room4.roomId,
+                ]);
+            });
+
+            it("Returns the predecessors of this room (with verify links)", () => {
+                const [room1, room2, room3, room4] = createRoomHistory();
+                const verifyLinks = true;
+                const history = client.getRoomUpgradeHistory(room4.roomId, verifyLinks);
+                expect(history.map((room) => room.roomId)).toEqual([
+                    room1.roomId,
+                    room2.roomId,
+                    room3.roomId,
+                    room4.roomId,
+                ]);
+            });
+
+            it("With verify links, rejects predecessors that don't point forwards", () => {
+                // Given successors point back with create events, but
+                // predecessors do not point forwards with tombstones
+                const [, , , room4] = createRoomHistory(true, false);
+
+                // When I ask for history with verifyLinks on
+                const verifyLinks = true;
+                const history = client.getRoomUpgradeHistory(room4.roomId, verifyLinks);
+
+                // Then the predecessors are not included in the history
+                expect(history.map((room) => room.roomId)).toEqual([room4.roomId]);
+            });
+
+            it("Without verify links, includes predecessors that don't point forwards", () => {
+                // Given successors point back with create events, but
+                // predecessors do not point forwards with tombstones
+                const [room1, room2, room3, room4] = createRoomHistory(true, false);
+
+                // When I ask for history with verifyLinks off
+                const verifyLinks = false;
+                const history = client.getRoomUpgradeHistory(room4.roomId, verifyLinks);
+
+                // Then the predecessors are included in the history
+                expect(history.map((room) => room.roomId)).toEqual([
+                    room1.roomId,
+                    room2.roomId,
+                    room3.roomId,
+                    room4.roomId,
+                ]);
+            });
+
+            it("Returns the subsequent rooms", () => {
+                const [room1, room2, room3, room4] = createRoomHistory();
+                const history = client.getRoomUpgradeHistory(room1.roomId);
+                expect(history.map((room) => room.roomId)).toEqual([
+                    room1.roomId,
+                    room2.roomId,
+                    room3.roomId,
+                    room4.roomId,
+                ]);
+            });
+
+            it("Returns the subsequent rooms (with verify links)", () => {
+                const [room1, room2, room3, room4] = createRoomHistory();
+                const verifyLinks = true;
+                const history = client.getRoomUpgradeHistory(room1.roomId, verifyLinks);
+                expect(history.map((room) => room.roomId)).toEqual([
+                    room1.roomId,
+                    room2.roomId,
+                    room3.roomId,
+                    room4.roomId,
+                ]);
+            });
+
+            it("With verify links, rejects successors that don't point backwards", () => {
+                // Given predecessors point forwards with tombstones, but
+                // successors do not point back with create events.
+                const [room1, , ,] = createRoomHistory(false, true);
+
+                // When I ask for history with verifyLinks on
+                const verifyLinks = true;
+                const history = client.getRoomUpgradeHistory(room1.roomId, verifyLinks);
+
+                // Then the successors are not included in the history
+                expect(history.map((room) => room.roomId)).toEqual([room1.roomId]);
+            });
+
+            it("Without verify links, includes predecessors that don't point forwards", () => {
+                // Given predecessors point forwards with tombstones, but
+                // successors do not point back with create events.
+                const [room1, room2, room3, room4] = createRoomHistory(false, true);
+
+                // When I ask for history with verifyLinks off
+                const verifyLinks = false;
+                const history = client.getRoomUpgradeHistory(room1.roomId, verifyLinks);
+
+                // Then the successors are included in the history
+                expect(history.map((room) => room.roomId)).toEqual([
+                    room1.roomId,
+                    room2.roomId,
+                    room3.roomId,
+                    room4.roomId,
+                ]);
+            });
+
+            it("Returns the predecessors and subsequent rooms", () => {
+                const [room1, room2, room3, room4] = createRoomHistory();
+                const history = client.getRoomUpgradeHistory(room3.roomId);
+                expect(history.map((room) => room.roomId)).toEqual([
+                    room1.roomId,
+                    room2.roomId,
+                    room3.roomId,
+                    room4.roomId,
+                ]);
+            });
+
+            it("Returns the predecessors and subsequent rooms (with verify links)", () => {
+                const [room1, room2, room3, room4] = createRoomHistory();
+                const verifyLinks = true;
+                const history = client.getRoomUpgradeHistory(room3.roomId, verifyLinks);
+                expect(history.map((room) => room.roomId)).toEqual([
+                    room1.roomId,
+                    room2.roomId,
+                    room3.roomId,
+                    room4.roomId,
+                ]);
+            });
+
+            it("Returns the predecessors and subsequent rooms using MSC3945 dynamic room predecessors", () => {
+                const [, , room3, , dynRoom1, dynRoom2, dynRoom4, dynRoom5] = createDynamicRoomHistory();
+                const useMsc3946 = true;
+                const verifyLinks = false;
+                const history = client.getRoomUpgradeHistory(room3.roomId, verifyLinks, useMsc3946);
+                expect(history.map((room) => room.roomId)).toEqual([
+                    dynRoom1.roomId,
+                    dynRoom2.roomId,
+                    room3.roomId,
+                    dynRoom4.roomId,
+                    dynRoom5.roomId,
+                ]);
+            });
+
+            it("When not asking for MSC3946, verified history without tombstones is empty", () => {
+                // There no tombstones to match the create events
+                const [, , room3] = createDynamicRoomHistory();
+                const useMsc3946 = false;
+                const verifyLinks = true;
+                const history = client.getRoomUpgradeHistory(room3.roomId, verifyLinks, useMsc3946);
+                // So we get no history back
+                expect(history.map((room) => room.roomId)).toEqual([room3.roomId]);
+            });
         });
     });
 });

spec/unit/models/beacon.spec.ts

@@ -14,8 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { REFERENCE_RELATION } from "matrix-events-sdk";
-
+import { REFERENCE_RELATION } from "../../../src/@types/extensible_events";
 import { MatrixEvent } from "../../../src";
 import { M_BEACON_INFO } from "../../../src/@types/beacon";
 import { isTimestampInDuration, Beacon, BeaconEvent } from "../../../src/models/beacon";

spec/unit/models/poll.spec.ts

@@ -0,0 +1,492 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { IEvent, MatrixEvent, PollEvent, Room } from "../../../src";
+import { REFERENCE_RELATION } from "../../../src/@types/extensible_events";
+import { M_POLL_END, M_POLL_KIND_DISCLOSED, M_POLL_RESPONSE } from "../../../src/@types/polls";
+import { PollStartEvent } from "../../../src/extensible_events_v1/PollStartEvent";
+import { Poll } from "../../../src/models/poll";
+import { getMockClientWithEventEmitter, mockClientMethodsUser } from "../../test-utils/client";
+
+jest.useFakeTimers();
+
+describe("Poll", () => {
+    const userId = "@alice:server.org";
+    const mockClient = getMockClientWithEventEmitter({
+        ...mockClientMethodsUser(userId),
+        relations: jest.fn(),
+    });
+    const roomId = "!room:server";
+    const room = new Room(roomId, mockClient, userId);
+    const maySendRedactionForEventSpy = jest.spyOn(room.currentState, "maySendRedactionForEvent");
+    // 14.03.2022 16:15
+    const now = 1647270879403;
+
+    const basePollStartEvent = new MatrixEvent({
+        ...PollStartEvent.from("What?", ["a", "b"], M_POLL_KIND_DISCLOSED.name).serialize(),
+        room_id: roomId,
+        sender: userId,
+    });
+    basePollStartEvent.event.event_id = "$12345";
+
+    beforeEach(() => {
+        jest.clearAllMocks();
+        jest.setSystemTime(now);
+
+        mockClient.relations.mockReset().mockResolvedValue({ events: [] });
+
+        maySendRedactionForEventSpy.mockClear().mockReturnValue(true);
+    });
+
+    let eventId = 1;
+    const makeRelatedEvent = (eventProps: Partial<IEvent>, timestamp = now): MatrixEvent => {
+        const event = new MatrixEvent({
+            ...eventProps,
+            content: {
+                ...(eventProps.content || {}),
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                    event_id: basePollStartEvent.getId(),
+                },
+            },
+        });
+        event.event.origin_server_ts = timestamp;
+        event.event.event_id = `${eventId++}`;
+        return event;
+    };
+
+    it("initialises with root event", () => {
+        const poll = new Poll(basePollStartEvent, mockClient, room);
+        expect(poll.roomId).toEqual(roomId);
+        expect(poll.pollId).toEqual(basePollStartEvent.getId());
+        expect(poll.pollEvent).toEqual(basePollStartEvent.unstableExtensibleEvent);
+        expect(poll.isEnded).toBe(false);
+    });
+
+    it("throws when poll start has no room id", () => {
+        const pollStartEvent = new MatrixEvent(
+            PollStartEvent.from("What?", ["a", "b"], M_POLL_KIND_DISCLOSED.name).serialize(),
+        );
+        expect(() => new Poll(pollStartEvent, mockClient, room)).toThrowError("Invalid poll start event.");
+    });
+
+    it("throws when poll start has no event id", () => {
+        const pollStartEvent = new MatrixEvent({
+            ...PollStartEvent.from("What?", ["a", "b"], M_POLL_KIND_DISCLOSED.name).serialize(),
+            room_id: roomId,
+        });
+        expect(() => new Poll(pollStartEvent, mockClient, room)).toThrowError("Invalid poll start event.");
+    });
+
+    describe("fetching responses", () => {
+        it("calls relations api and emits", async () => {
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            const emitSpy = jest.spyOn(poll, "emit");
+            const fetchResponsePromise = poll.getResponses();
+            expect(poll.isFetchingResponses).toBe(true);
+            const responses = await fetchResponsePromise;
+            expect(poll.isFetchingResponses).toBe(false);
+            expect(mockClient.relations).toHaveBeenCalledWith(
+                roomId,
+                basePollStartEvent.getId(),
+                "m.reference",
+                undefined,
+                { from: undefined },
+            );
+            expect(emitSpy).toHaveBeenCalledWith(PollEvent.Responses, responses);
+        });
+
+        it("returns existing responses object after initial fetch", async () => {
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            const responses = await poll.getResponses();
+            const responses2 = await poll.getResponses();
+            // only fetched relations once
+            expect(mockClient.relations).toHaveBeenCalledTimes(1);
+            // strictly equal
+            expect(responses).toBe(responses2);
+        });
+
+        it("waits for existing relations request to finish when getting responses", async () => {
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            const firstResponsePromise = poll.getResponses();
+            const secondResponsePromise = poll.getResponses();
+            await firstResponsePromise;
+            expect(firstResponsePromise).toEqual(secondResponsePromise);
+            await secondResponsePromise;
+            expect(mockClient.relations).toHaveBeenCalledTimes(1);
+        });
+
+        it("filters relations for relevent response events", async () => {
+            const replyEvent = new MatrixEvent({ type: "m.room.message" });
+            const stableResponseEvent = makeRelatedEvent({ type: M_POLL_RESPONSE.stable! });
+            const unstableResponseEvent = makeRelatedEvent({ type: M_POLL_RESPONSE.unstable });
+
+            mockClient.relations.mockResolvedValue({
+                events: [replyEvent, stableResponseEvent, unstableResponseEvent],
+            });
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            const responses = await poll.getResponses();
+            expect(responses.getRelations()).toEqual([stableResponseEvent, unstableResponseEvent]);
+        });
+
+        describe("with multiple pages of relations", () => {
+            const makeResponses = (count = 1, timestamp = now): MatrixEvent[] =>
+                new Array(count)
+                    .fill("x")
+                    .map((_x, index) =>
+                        makeRelatedEvent(
+                            { type: M_POLL_RESPONSE.stable!, sender: "@bob@server.org" },
+                            timestamp + index,
+                        ),
+                    );
+
+            it("page relations responses", async () => {
+                const responseEvents = makeResponses(6);
+                mockClient.relations
+                    .mockResolvedValueOnce({
+                        events: responseEvents.slice(0, 2),
+                        nextBatch: "test-next-1",
+                    })
+                    .mockResolvedValueOnce({
+                        events: responseEvents.slice(2, 4),
+                        nextBatch: "test-next-2",
+                    })
+                    .mockResolvedValueOnce({
+                        events: responseEvents.slice(4),
+                    });
+
+                const poll = new Poll(basePollStartEvent, mockClient, room);
+                jest.spyOn(poll, "emit");
+                const responses = await poll.getResponses();
+
+                expect(mockClient.relations.mock.calls).toEqual([
+                    [roomId, basePollStartEvent.getId(), "m.reference", undefined, { from: undefined }],
+                    [roomId, basePollStartEvent.getId(), "m.reference", undefined, { from: "test-next-1" }],
+                    [roomId, basePollStartEvent.getId(), "m.reference", undefined, { from: "test-next-2" }],
+                ]);
+
+                expect(poll.emit).toHaveBeenCalledTimes(3);
+                expect(poll.isFetchingResponses).toBeFalsy();
+                expect(responses.getRelations().length).toEqual(6);
+            });
+        });
+
+        describe("with poll end event", () => {
+            const stablePollEndEvent = makeRelatedEvent({ type: M_POLL_END.stable!, sender: "@bob@server.org" });
+            const unstablePollEndEvent = makeRelatedEvent({ type: M_POLL_END.unstable!, sender: "@bob@server.org" });
+            const responseEventBeforeEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now - 1000);
+            const responseEventAtEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now);
+            const responseEventAfterEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now + 1000);
+
+            beforeEach(() => {
+                mockClient.relations.mockResolvedValue({
+                    events: [responseEventAfterEnd, responseEventAtEnd, responseEventBeforeEnd, stablePollEndEvent],
+                });
+            });
+
+            it("sets poll end event with stable event type", async () => {
+                const poll = new Poll(basePollStartEvent, mockClient, room);
+                jest.spyOn(poll, "emit");
+                await poll.getResponses();
+
+                expect(maySendRedactionForEventSpy).toHaveBeenCalledWith(basePollStartEvent, "@bob@server.org");
+                expect(poll.isEnded).toBe(true);
+                expect(poll.emit).toHaveBeenCalledWith(PollEvent.End);
+            });
+
+            it("sets poll end event when endevent sender also created the poll, but does not have redaction rights", async () => {
+                const pollStartEvent = new MatrixEvent({
+                    ...PollStartEvent.from("What?", ["a", "b"], M_POLL_KIND_DISCLOSED.name).serialize(),
+                    room_id: roomId,
+                    sender: "@bob:domain.org",
+                });
+                pollStartEvent.event.event_id = "$6789";
+                const poll = new Poll(pollStartEvent, mockClient, room);
+                const pollEndEvent = makeRelatedEvent({ type: M_POLL_END.stable!, sender: "@bob:domain.org" });
+                mockClient.relations.mockResolvedValue({
+                    events: [pollEndEvent],
+                });
+                maySendRedactionForEventSpy.mockReturnValue(false);
+                jest.spyOn(poll, "emit");
+                await poll.getResponses();
+
+                expect(maySendRedactionForEventSpy).not.toHaveBeenCalled();
+                expect(poll.isEnded).toBe(true);
+                expect(poll.emit).toHaveBeenCalledWith(PollEvent.End);
+            });
+
+            it("sets poll end event with unstable event type", async () => {
+                mockClient.relations.mockResolvedValue({
+                    events: [unstablePollEndEvent],
+                });
+                const poll = new Poll(basePollStartEvent, mockClient, room);
+                jest.spyOn(poll, "emit");
+                await poll.getResponses();
+
+                expect(poll.isEnded).toBe(true);
+                expect(poll.emit).toHaveBeenCalledWith(PollEvent.End);
+            });
+
+            it("filters out responses that were sent after poll end", async () => {
+                const poll = new Poll(basePollStartEvent, mockClient, room);
+                const responses = await poll.getResponses();
+
+                // just response type events
+                // and response with ts after poll end event is excluded
+                expect(responses.getRelations()).toEqual([responseEventAtEnd, responseEventBeforeEnd]);
+            });
+        });
+    });
+
+    describe("onNewRelation()", () => {
+        it("discards response if poll responses have not been initialised", () => {
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            jest.spyOn(poll, "emit");
+            const responseEvent = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now);
+
+            poll.onNewRelation(responseEvent);
+
+            // did not add response -> no emit
+            expect(poll.emit).not.toHaveBeenCalled();
+        });
+
+        it("sets poll end event when responses are not initialised", () => {
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            jest.spyOn(poll, "emit");
+            const stablePollEndEvent = makeRelatedEvent({ type: M_POLL_END.stable!, sender: userId });
+
+            poll.onNewRelation(stablePollEndEvent);
+
+            expect(poll.emit).toHaveBeenCalledWith(PollEvent.End);
+        });
+
+        it("does not set poll end event when sent by invalid user", async () => {
+            maySendRedactionForEventSpy.mockReturnValue(false);
+            const stablePollEndEvent = makeRelatedEvent({ type: M_POLL_END.stable!, sender: "@charlie:server.org" });
+            const responseEventAfterEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now + 1000);
+            mockClient.relations.mockResolvedValue({
+                events: [responseEventAfterEnd],
+            });
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            await poll.getResponses();
+            jest.spyOn(poll, "emit");
+
+            poll.onNewRelation(stablePollEndEvent);
+
+            // didn't end, didn't refilter responses
+            expect(poll.emit).not.toHaveBeenCalled();
+            expect(poll.isEnded).toBeFalsy();
+            expect(maySendRedactionForEventSpy).toHaveBeenCalledWith(basePollStartEvent, "@charlie:server.org");
+        });
+
+        it("does not set poll end event when an earlier end event already exists", async () => {
+            const earlierPollEndEvent = makeRelatedEvent(
+                { type: M_POLL_END.stable!, sender: "@valid:server.org" },
+                now,
+            );
+            const laterPollEndEvent = makeRelatedEvent(
+                { type: M_POLL_END.stable!, sender: "@valid:server.org" },
+                now + 2000,
+            );
+
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            await poll.getResponses();
+
+            poll.onNewRelation(earlierPollEndEvent);
+
+            // first end event set correctly
+            expect(poll.isEnded).toBeTruthy();
+
+            // reset spy count
+            jest.spyOn(poll, "emit").mockClear();
+
+            poll.onNewRelation(laterPollEndEvent);
+            // didn't set new end event, didn't refilter responses
+            expect(poll.emit).not.toHaveBeenCalled();
+            expect(poll.isEnded).toBeTruthy();
+        });
+
+        it("replaces poll end event and refilters when an older end event already exists", async () => {
+            const earlierPollEndEvent = makeRelatedEvent(
+                { type: M_POLL_END.stable!, sender: "@valid:server.org" },
+                now,
+            );
+            const laterPollEndEvent = makeRelatedEvent(
+                { type: M_POLL_END.stable!, sender: "@valid:server.org" },
+                now + 2000,
+            );
+            const responseEventBeforeEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now - 1000);
+            const responseEventAtEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now);
+            const responseEventAfterEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now + 1000);
+            mockClient.relations.mockResolvedValue({
+                events: [responseEventAfterEnd, responseEventAtEnd, responseEventBeforeEnd, laterPollEndEvent],
+            });
+
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            const responses = await poll.getResponses();
+
+            // all responses have a timestamp < laterPollEndEvent
+            expect(responses.getRelations().length).toEqual(3);
+            // first end event set correctly
+            expect(poll.isEnded).toBeTruthy();
+
+            // reset spy count
+            jest.spyOn(poll, "emit").mockClear();
+
+            // add a valid end event with earlier timestamp
+            poll.onNewRelation(earlierPollEndEvent);
+
+            // emitted new end event
+            expect(poll.emit).toHaveBeenCalledWith(PollEvent.End);
+            // filtered responses and emitted
+            expect(poll.emit).toHaveBeenCalledWith(PollEvent.Responses, responses);
+            expect(responses.getRelations()).toEqual([responseEventAtEnd, responseEventBeforeEnd]);
+        });
+
+        it("does not set poll end event when sent by invalid user", async () => {
+            maySendRedactionForEventSpy.mockReturnValue(false);
+            const stablePollEndEvent = makeRelatedEvent({ type: M_POLL_END.stable!, sender: "@charlie:server.org" });
+            const responseEventAfterEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now + 1000);
+            mockClient.relations.mockResolvedValue({
+                events: [responseEventAfterEnd],
+            });
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            await poll.getResponses();
+            jest.spyOn(poll, "emit");
+
+            poll.onNewRelation(stablePollEndEvent);
+
+            // didn't end, didn't refilter responses
+            expect(poll.emit).not.toHaveBeenCalled();
+            expect(poll.isEnded).toBeFalsy();
+            expect(maySendRedactionForEventSpy).toHaveBeenCalledWith(basePollStartEvent, "@charlie:server.org");
+        });
+
+        it("does not set poll end event when an earlier end event already exists", async () => {
+            const earlierPollEndEvent = makeRelatedEvent(
+                { type: M_POLL_END.stable!, sender: "@valid:server.org" },
+                now,
+            );
+            const laterPollEndEvent = makeRelatedEvent(
+                { type: M_POLL_END.stable!, sender: "@valid:server.org" },
+                now + 2000,
+            );
+
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            await poll.getResponses();
+
+            poll.onNewRelation(earlierPollEndEvent);
+
+            // first end event set correctly
+            expect(poll.isEnded).toBeTruthy();
+
+            // reset spy count
+            jest.spyOn(poll, "emit").mockClear();
+
+            poll.onNewRelation(laterPollEndEvent);
+            // didn't set new end event, didn't refilter responses
+            expect(poll.emit).not.toHaveBeenCalled();
+            expect(poll.isEnded).toBeTruthy();
+        });
+
+        it("replaces poll end event and refilters when an older end event already exists", async () => {
+            const earlierPollEndEvent = makeRelatedEvent(
+                { type: M_POLL_END.stable!, sender: "@valid:server.org" },
+                now,
+            );
+            const laterPollEndEvent = makeRelatedEvent(
+                { type: M_POLL_END.stable!, sender: "@valid:server.org" },
+                now + 2000,
+            );
+            const responseEventBeforeEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now - 1000);
+            const responseEventAtEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now);
+            const responseEventAfterEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now + 1000);
+            mockClient.relations.mockResolvedValue({
+                events: [responseEventAfterEnd, responseEventAtEnd, responseEventBeforeEnd, laterPollEndEvent],
+            });
+
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            const responses = await poll.getResponses();
+
+            // all responses have a timestamp < laterPollEndEvent
+            expect(responses.getRelations().length).toEqual(3);
+            // first end event set correctly
+            expect(poll.isEnded).toBeTruthy();
+
+            // reset spy count
+            jest.spyOn(poll, "emit").mockClear();
+
+            // add a valid end event with earlier timestamp
+            poll.onNewRelation(earlierPollEndEvent);
+
+            // emitted new end event
+            expect(poll.emit).toHaveBeenCalledWith(PollEvent.End);
+            // filtered responses and emitted
+            expect(poll.emit).toHaveBeenCalledWith(PollEvent.Responses, responses);
+            expect(responses.getRelations()).toEqual([responseEventAtEnd, responseEventBeforeEnd]);
+        });
+
+        it("sets poll end event and refilters responses based on timestamp", async () => {
+            const stablePollEndEvent = makeRelatedEvent({ type: M_POLL_END.stable!, sender: userId });
+            const responseEventBeforeEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now - 1000);
+            const responseEventAtEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now);
+            const responseEventAfterEnd = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now + 1000);
+            mockClient.relations.mockResolvedValue({
+                events: [responseEventAfterEnd, responseEventAtEnd, responseEventBeforeEnd],
+            });
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            const responses = await poll.getResponses();
+            jest.spyOn(poll, "emit");
+
+            expect(responses.getRelations().length).toEqual(3);
+            poll.onNewRelation(stablePollEndEvent);
+
+            expect(poll.emit).toHaveBeenCalledWith(PollEvent.End);
+            expect(poll.emit).toHaveBeenCalledWith(PollEvent.Responses, responses);
+            expect(responses.getRelations().length).toEqual(2);
+            // after end timestamp event is removed
+            expect(responses.getRelations()).toEqual([responseEventAtEnd, responseEventBeforeEnd]);
+        });
+
+        it("filters out irrelevant relations", async () => {
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            // init responses
+            const responses = await poll.getResponses();
+            jest.spyOn(poll, "emit");
+            const replyEvent = new MatrixEvent({ type: "m.room.message" });
+
+            poll.onNewRelation(replyEvent);
+
+            // did not add response -> no emit
+            expect(poll.emit).not.toHaveBeenCalled();
+            expect(responses.getRelations().length).toEqual(0);
+        });
+
+        it("adds poll response relations to responses", async () => {
+            const poll = new Poll(basePollStartEvent, mockClient, room);
+            // init responses
+            const responses = await poll.getResponses();
+            jest.spyOn(poll, "emit");
+            const responseEvent = makeRelatedEvent({ type: M_POLL_RESPONSE.name }, now);
+
+            poll.onNewRelation(responseEvent);
+
+            // did not add response -> no emit
+            expect(poll.emit).toHaveBeenCalledWith(PollEvent.Responses, responses);
+            expect(responses.getRelations()).toEqual([responseEvent]);
+        });
+    });
+});

spec/unit/models/thread.spec.ts

@@ -84,7 +84,7 @@ describe("Thread", () => {
                 ...mockClientMethodsUser(),
                 getRoom: jest.fn().mockImplementation(() => room),
                 decryptEventIfNeeded: jest.fn().mockResolvedValue(void 0),
-                supportsExperimentalThreads: jest.fn().mockReturnValue(true),
+                supportsThreads: jest.fn().mockReturnValue(true),
             });
             client.reEmitter = mock(ReEmitter, "ReEmitter");
             client.canSupport = new Map();
@@ -195,7 +195,7 @@ describe("Thread", () => {
                 ...mockClientMethodsUser(),
                 getRoom: jest.fn().mockImplementation(() => room),
                 decryptEventIfNeeded: jest.fn().mockResolvedValue(void 0),
-                supportsExperimentalThreads: jest.fn().mockReturnValue(true),
+                supportsThreads: jest.fn().mockReturnValue(true),
             });
             client.reEmitter = mock(ReEmitter, "ReEmitter");
             client.canSupport = new Map();

spec/unit/notifications.spec.ts

@@ -56,7 +56,7 @@ describe("fixNotificationCountOnDecryption", () => {
             getPushActionsForEvent: jest.fn().mockReturnValue(mkPushAction(true, true)),
             getRoom: jest.fn().mockImplementation(() => room),
             decryptEventIfNeeded: jest.fn().mockResolvedValue(void 0),
-            supportsExperimentalThreads: jest.fn().mockReturnValue(true),
+            supportsThreads: jest.fn().mockReturnValue(true),
         });
         mockClient.reEmitter = mock(ReEmitter, "ReEmitter");
         mockClient.canSupport = new Map();

spec/unit/read-receipt.spec.ts

@@ -18,7 +18,6 @@ import MockHttpBackend from "matrix-mock-request";
 
 import { MAIN_ROOM_TIMELINE, ReceiptType } from "../../src/@types/read_receipts";
 import { MatrixClient } from "../../src/client";
-import { Feature, ServerSupport } from "../../src/feature";
 import { EventType } from "../../src/matrix";
 import { synthesizeReceipt } from "../../src/models/read-receipt";
 import { encodeUri } from "../../src/utils";
@@ -70,10 +69,6 @@ const roomEvent = utils.mkEvent({
     },
 });
 
-function mockServerSideSupport(client: MatrixClient, serverSideSupport: ServerSupport) {
-    client.canSupport.set(Feature.ThreadUnreadNotifications, serverSideSupport);
-}
-
 describe("Read receipt", () => {
     beforeEach(() => {
         httpBackend = new MockHttpBackend();
@@ -101,7 +96,6 @@ describe("Read receipt", () => {
                 })
                 .respond(200, {});
 
-            mockServerSideSupport(client, ServerSupport.Stable);
             client.sendReceipt(threadEvent, ReceiptType.Read, {});
 
             await httpBackend.flushAllExpected();
@@ -123,7 +117,6 @@ describe("Read receipt", () => {
                 })
                 .respond(200, {});
 
-            mockServerSideSupport(client, ServerSupport.Stable);
             client.sendReadReceipt(threadEvent, ReceiptType.Read, true);
 
             await httpBackend.flushAllExpected();
@@ -145,56 +138,11 @@ describe("Read receipt", () => {
                 })
                 .respond(200, {});
 
-            mockServerSideSupport(client, ServerSupport.Stable);
             client.sendReceipt(roomEvent, ReceiptType.Read, {});
 
             await httpBackend.flushAllExpected();
             await flushPromises();
         });
-
-        it("sends a room read receipt when there's no server support", async () => {
-            httpBackend
-                .when(
-                    "POST",
-                    encodeUri("/rooms/$roomId/receipt/$receiptType/$eventId", {
-                        $roomId: ROOM_ID,
-                        $receiptType: ReceiptType.Read,
-                        $eventId: threadEvent.getId()!,
-                    }),
-                )
-                .check((request) => {
-                    expect(request.data.thread_id).toBeUndefined();
-                })
-                .respond(200, {});
-
-            mockServerSideSupport(client, ServerSupport.Unsupported);
-            client.sendReceipt(threadEvent, ReceiptType.Read, {});
-
-            await httpBackend.flushAllExpected();
-            await flushPromises();
-        });
-
-        it("sends a valid room read receipt even when body omitted", async () => {
-            httpBackend
-                .when(
-                    "POST",
-                    encodeUri("/rooms/$roomId/receipt/$receiptType/$eventId", {
-                        $roomId: ROOM_ID,
-                        $receiptType: ReceiptType.Read,
-                        $eventId: threadEvent.getId()!,
-                    }),
-                )
-                .check((request) => {
-                    expect(request.data).toEqual({});
-                })
-                .respond(200, {});
-
-            mockServerSideSupport(client, ServerSupport.Unsupported);
-            client.sendReceipt(threadEvent, ReceiptType.Read, undefined);
-
-            await httpBackend.flushAllExpected();
-            await flushPromises();
-        });
     });
 
     describe("synthesizeReceipt", () => {

spec/unit/relations.spec.ts

@@ -14,8 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { M_POLL_START } from "matrix-events-sdk";
-
+import { M_POLL_START } from "../../src/@types/polls";
 import { EventTimelineSet } from "../../src/models/event-timeline-set";
 import { MatrixEvent, MatrixEventEvent } from "../../src/models/event";
 import { Room } from "../../src/models/room";

spec/unit/room.spec.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2022 The Matrix.org Foundation C.I.C.
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@ limitations under the License.
  */
 
 import { mocked } from "jest-mock";
+import { M_POLL_KIND_DISCLOSED, M_POLL_RESPONSE, PollStartEvent } from "matrix-events-sdk";
 
 import * as utils from "../test-utils/test-utils";
 import { emitPromise } from "../test-utils/test-utils";
@@ -37,6 +38,7 @@ import {
     MatrixEvent,
     MatrixEventEvent,
     PendingEventOrdering,
+    PollEvent,
     RelationType,
     RoomEvent,
     RoomMember,
@@ -1622,7 +1624,7 @@ describe("Room", function () {
     describe("addPendingEvent", function () {
         it("should add pending events to the pendingEventList if " + "pendingEventOrdering == 'detached'", function () {
             const client = new TestClient("@alice:example.com", "alicedevice").client;
-            client.supportsExperimentalThreads = () => true;
+            client.supportsThreads = () => true;
             const room = new Room(roomId, client, userA, {
                 pendingEventOrdering: PendingEventOrdering.Detached,
             });
@@ -2468,7 +2470,7 @@ describe("Room", function () {
         });
 
         it("Edits update the lastReply event", async () => {
-            room.client.supportsExperimentalThreads = () => true;
+            room.client.supportsThreads = () => true;
             Thread.setServerSideSupport(FeatureSupport.Stable);
 
             const randomMessage = mkMessage();
@@ -2539,7 +2541,7 @@ describe("Room", function () {
         });
 
         it("Redactions to thread responses decrement the length", async () => {
-            room.client.supportsExperimentalThreads = () => true;
+            room.client.supportsThreads = () => true;
             Thread.setServerSideSupport(FeatureSupport.Stable);
 
             const threadRoot = mkMessage();
@@ -2606,7 +2608,7 @@ describe("Room", function () {
         });
 
         it("Redactions to reactions in threads do not decrement the length", async () => {
-            room.client.supportsExperimentalThreads = () => true;
+            room.client.supportsThreads = () => true;
             Thread.setServerSideSupport(FeatureSupport.Stable);
 
             const threadRoot = mkMessage();
@@ -2646,7 +2648,7 @@ describe("Room", function () {
         });
 
         it("should not decrement the length when the thread root is redacted", async () => {
-            room.client.supportsExperimentalThreads = () => true;
+            room.client.supportsThreads = () => true;
             Thread.setServerSideSupport(FeatureSupport.Stable);
 
             const threadRoot = mkMessage();
@@ -2687,7 +2689,7 @@ describe("Room", function () {
         });
 
         it("Redacting the lastEvent finds a new lastEvent", async () => {
-            room.client.supportsExperimentalThreads = () => true;
+            room.client.supportsThreads = () => true;
             Thread.setServerSideSupport(FeatureSupport.Stable);
             Thread.setServerSideListSupport(FeatureSupport.Stable);
 
@@ -2794,7 +2796,7 @@ describe("Room", function () {
 
     describe("eventShouldLiveIn", () => {
         const client = new TestClient(userA).client;
-        client.supportsExperimentalThreads = () => true;
+        client.supportsThreads = () => true;
         Thread.setServerSideSupport(FeatureSupport.Stable);
         const room = new Room(roomId, client, userA);
 
@@ -3228,12 +3230,84 @@ describe("Room", function () {
         });
     });
 
+    describe("processPollEvents()", () => {
+        let room: Room;
+        let client: MatrixClient;
+
+        beforeEach(() => {
+            client = getMockClientWithEventEmitter({
+                decryptEventIfNeeded: jest.fn(),
+            });
+            room = new Room(roomId, client, userA);
+            jest.spyOn(room, "emit").mockClear();
+        });
+
+        const makePollStart = (id: string): MatrixEvent => {
+            const event = new MatrixEvent({
+                ...PollStartEvent.from("What?", ["a", "b"], M_POLL_KIND_DISCLOSED.name).serialize(),
+                room_id: roomId,
+            });
+            event.event.event_id = id;
+            return event;
+        };
+
+        it("adds poll models to room state for a poll start event ", async () => {
+            const pollStartEvent = makePollStart("1");
+            const events = [pollStartEvent];
+
+            await room.processPollEvents(events);
+            expect(client.decryptEventIfNeeded).toHaveBeenCalledWith(pollStartEvent);
+            const pollInstance = room.polls.get(pollStartEvent.getId()!);
+            expect(pollInstance).toBeTruthy();
+
+            expect(room.emit).toHaveBeenCalledWith(PollEvent.New, pollInstance);
+        });
+
+        it("adds related events to poll models", async () => {
+            const pollStartEvent = makePollStart("1");
+            const pollStartEvent2 = makePollStart("2");
+            const events = [pollStartEvent, pollStartEvent2];
+            const pollResponseEvent = new MatrixEvent({
+                type: M_POLL_RESPONSE.name,
+                content: {
+                    "m.relates_to": {
+                        rel_type: RelationType.Reference,
+                        event_id: pollStartEvent.getId(),
+                    },
+                },
+            });
+            const messageEvent = new MatrixEvent({
+                type: "m.room.messsage",
+                content: {
+                    text: "hello",
+                },
+            });
+
+            // init poll
+            await room.processPollEvents(events);
+
+            const poll = room.polls.get(pollStartEvent.getId()!)!;
+            const poll2 = room.polls.get(pollStartEvent2.getId()!)!;
+            jest.spyOn(poll, "onNewRelation");
+            jest.spyOn(poll2, "onNewRelation");
+
+            await room.processPollEvents([pollResponseEvent, messageEvent]);
+
+            // only called for relevant event
+            expect(poll.onNewRelation).toHaveBeenCalledTimes(1);
+            expect(poll.onNewRelation).toHaveBeenCalledWith(pollResponseEvent);
+
+            // only called on poll with relation
+            expect(poll2.onNewRelation).not.toHaveBeenCalled();
+        });
+    });
+
     describe("findPredecessorRoomId", () => {
         let client: MatrixClient | null = null;
         beforeEach(() => {
             client = getMockClientWithEventEmitter({
                 ...mockClientMethodsUser(),
-                supportsExperimentalThreads: jest.fn().mockReturnValue(true),
+                supportsThreads: jest.fn().mockReturnValue(true),
             });
         });
 
@@ -3266,21 +3340,90 @@ describe("Room", function () {
             });
         }
 
+        function predecessorEvent(
+            newRoomId: string,
+            predecessorRoomId: string,
+            tombstoneEventId: string | null = null,
+        ): MatrixEvent {
+            const content =
+                tombstoneEventId === null
+                    ? { predecessor_room_id: predecessorRoomId }
+                    : { predecessor_room_id: predecessorRoomId, last_known_event_id: tombstoneEventId };
+
+            return new MatrixEvent({
+                content,
+                event_id: `predecessor_event_id_pred_${predecessorRoomId}`,
+                origin_server_ts: 1432735824653,
+                room_id: newRoomId,
+                sender: "@daryl:alexandria.example.com",
+                state_key: "",
+                type: "org.matrix.msc3946.room_predecessor",
+            });
+        }
+
         it("Returns null if there is no create event", () => {
             const room = new Room("roomid", client!, "@u:example.com");
-            expect(room.findPredecessorRoomId()).toBeNull();
+            expect(room.findPredecessor()).toBeNull();
         });
 
         it("Returns null if the create event has no predecessor", () => {
             const room = new Room("roomid", client!, "@u:example.com");
             room.addLiveEvents([roomCreateEvent("roomid", null)]);
-            expect(room.findPredecessorRoomId()).toBeNull();
+            expect(room.findPredecessor()).toBeNull();
         });
 
         it("Returns the predecessor ID if one is provided via create event", () => {
             const room = new Room("roomid", client!, "@u:example.com");
             room.addLiveEvents([roomCreateEvent("roomid", "replacedroomid")]);
-            expect(room.findPredecessorRoomId()).toBe("replacedroomid");
+            expect(room.findPredecessor()).toEqual({ roomId: "replacedroomid", eventId: "id_of_last_known_event" });
+        });
+
+        it("Prefers the m.predecessor event if one exists", () => {
+            const room = new Room("roomid", client!, "@u:example.com");
+            room.addLiveEvents([
+                roomCreateEvent("roomid", "replacedroomid"),
+                predecessorEvent("roomid", "otherreplacedroomid"),
+            ]);
+            const useMsc3946 = true;
+            expect(room.findPredecessor(useMsc3946)).toEqual({
+                roomId: "otherreplacedroomid",
+                eventId: null, // m.predecessor did not include an event_id
+            });
+        });
+
+        it("uses the m.predecessor event ID if provided", () => {
+            const room = new Room("roomid", client!, "@u:example.com");
+            room.addLiveEvents([
+                roomCreateEvent("roomid", "replacedroomid"),
+                predecessorEvent("roomid", "otherreplacedroomid", "lstevtid"),
+            ]);
+            const useMsc3946 = true;
+            expect(room.findPredecessor(useMsc3946)).toEqual({
+                roomId: "otherreplacedroomid",
+                eventId: "lstevtid",
+            });
+        });
+
+        it("Ignores the m.predecessor event if we don't ask to use it", () => {
+            const room = new Room("roomid", client!, "@u:example.com");
+            room.addLiveEvents([
+                roomCreateEvent("roomid", "replacedroomid"),
+                predecessorEvent("roomid", "otherreplacedroomid"),
+            ]);
+            // Don't provide an argument for msc3946ProcessDynamicPredecessor -
+            // we should ignore the predecessor event.
+            expect(room.findPredecessor()).toEqual({ roomId: "replacedroomid", eventId: "id_of_last_known_event" });
+        });
+
+        it("Ignores the m.predecessor event and returns null if we don't ask to use it", () => {
+            const room = new Room("roomid", client!, "@u:example.com");
+            room.addLiveEvents([
+                roomCreateEvent("roomid", null), // Create event has no predecessor
+                predecessorEvent("roomid", "otherreplacedroomid", "lastevtid"),
+            ]);
+            // Don't provide an argument for msc3946ProcessDynamicPredecessor -
+            // we should ignore the predecessor event.
+            expect(room.findPredecessor()).toBeNull();
         });
     });
 });

spec/unit/rust-crypto/KeyClaimManager.spec.ts

@@ -0,0 +1,158 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-js";
+import fetchMock from "fetch-mock-jest";
+import { Mocked } from "jest-mock";
+import { KeysClaimRequest, UserId } from "@matrix-org/matrix-sdk-crypto-js";
+
+import { OutgoingRequestProcessor } from "../../../src/rust-crypto/OutgoingRequestProcessor";
+import { KeyClaimManager } from "../../../src/rust-crypto/KeyClaimManager";
+import { TypedEventEmitter } from "../../../src/models/typed-event-emitter";
+import { HttpApiEvent, HttpApiEventHandlerMap, MatrixHttpApi } from "../../../src";
+
+afterEach(() => {
+    fetchMock.mockReset();
+});
+
+describe("KeyClaimManager", () => {
+    /* for these tests, we connect a KeyClaimManager to a mock OlmMachine, and a real OutgoingRequestProcessor
+     * (which is connected to a mock fetch implementation)
+     */
+
+    /** the KeyClaimManager implementation under test */
+    let keyClaimManager: KeyClaimManager;
+
+    /** a mocked-up OlmMachine which the OutgoingRequestProcessor and KeyClaimManager are connected to */
+    let olmMachine: Mocked<RustSdkCryptoJs.OlmMachine>;
+
+    beforeEach(async () => {
+        const dummyEventEmitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
+        const httpApi = new MatrixHttpApi(dummyEventEmitter, {
+            baseUrl: "https://example.com",
+            prefix: "/_matrix",
+            onlyData: true,
+        });
+
+        olmMachine = {
+            getMissingSessions: jest.fn(),
+            markRequestAsSent: jest.fn(),
+        } as unknown as Mocked<RustSdkCryptoJs.OlmMachine>;
+
+        const outgoingRequestProcessor = new OutgoingRequestProcessor(olmMachine, httpApi);
+
+        keyClaimManager = new KeyClaimManager(olmMachine, outgoingRequestProcessor);
+    });
+
+    /**
+     * Returns a promise which resolve once olmMachine.markRequestAsSent is called.
+     *
+     * The call itself will block initially.
+     *
+     * The promise returned by this function yields a callback function, which should be called to unblock the
+     * markRequestAsSent call.
+     */
+    function awaitCallToMarkRequestAsSent(): Promise<() => void> {
+        return new Promise<() => void>((resolveCalledPromise, _reject) => {
+            olmMachine.markRequestAsSent.mockImplementationOnce(async () => {
+                // the mock implementation returns a promise...
+                const completePromise = new Promise<void>((resolveCompletePromise, _reject) => {
+                    // ...  and we now resolve the original promise with the resolver for that second promise.
+                    resolveCalledPromise(resolveCompletePromise);
+                });
+                return completePromise;
+            });
+        });
+    }
+
+    it("should claim missing keys", async () => {
+        const u1 = new UserId("@alice:example.com");
+        const u2 = new UserId("@bob:example.com");
+
+        // stub out olmMachine.getMissingSessions(), with a result indicating that it needs a keyclaim
+        const keysClaimRequest = new KeysClaimRequest("1234", '{ "k1": "v1" }');
+        olmMachine.getMissingSessions.mockResolvedValueOnce(keysClaimRequest);
+
+        // have the claim request return a 200
+        fetchMock.postOnce("https://example.com/_matrix/client/v3/keys/claim", '{ "k": "v" }');
+
+        // also stub out olmMachine.markRequestAsSent
+        olmMachine.markRequestAsSent.mockResolvedValueOnce(undefined);
+
+        // fire off the request
+        await keyClaimManager.ensureSessionsForUsers([u1, u2]);
+
+        // check that all the calls were made
+        expect(olmMachine.getMissingSessions).toHaveBeenCalledWith([u1, u2]);
+        expect(fetchMock).toHaveFetched("https://example.com/_matrix/client/v3/keys/claim", {
+            method: "POST",
+            body: { k1: "v1" },
+        });
+        expect(olmMachine.markRequestAsSent).toHaveBeenCalledWith("1234", keysClaimRequest.type, '{ "k": "v" }');
+    });
+
+    it("should wait for previous claims to complete before making another", async () => {
+        const u1 = new UserId("@alice:example.com");
+        const u2 = new UserId("@bob:example.com");
+
+        // stub out olmMachine.getMissingSessions(), with a result indicating that it needs a keyclaim
+        const keysClaimRequest = new KeysClaimRequest("1234", '{ "k1": "v1" }');
+        olmMachine.getMissingSessions.mockResolvedValue(keysClaimRequest);
+
+        // have the claim request return a 200
+        fetchMock.post("https://example.com/_matrix/client/v3/keys/claim", '{ "k": "v" }');
+
+        // stub out olmMachine.markRequestAsSent, and have it block
+        let markRequestAsSentPromise = awaitCallToMarkRequestAsSent();
+
+        // fire off two requests, and keep track of whether their promises resolve
+        let req1Resolved = false;
+        keyClaimManager.ensureSessionsForUsers([u1]).then(() => {
+            req1Resolved = true;
+        });
+        let req2Resolved = false;
+        const req2 = keyClaimManager.ensureSessionsForUsers([u2]).then(() => {
+            req2Resolved = true;
+        });
+
+        // now: wait for the (first) call to OlmMachine.markRequestAsSent
+        let resolveMarkRequestAsSentCallback = await markRequestAsSentPromise;
+
+        // at this point, there should have been a single call to getMissingSessions, and a single fetch; and neither
+        // call to ensureSessionsAsUsers should have completed
+        expect(olmMachine.getMissingSessions).toHaveBeenCalledWith([u1]);
+        expect(olmMachine.getMissingSessions).toHaveBeenCalledTimes(1);
+        expect(fetchMock).toHaveBeenCalledTimes(1);
+        expect(req1Resolved).toBe(false);
+        expect(req2Resolved).toBe(false);
+
+        // await the next call to markRequestAsSent, and release the first one
+        markRequestAsSentPromise = awaitCallToMarkRequestAsSent();
+        resolveMarkRequestAsSentCallback();
+        resolveMarkRequestAsSentCallback = await markRequestAsSentPromise;
+
+        // the first request should now have completed, and we should have more calls and fetches
+        expect(olmMachine.getMissingSessions).toHaveBeenCalledWith([u2]);
+        expect(olmMachine.getMissingSessions).toHaveBeenCalledTimes(2);
+        expect(fetchMock).toHaveBeenCalledTimes(2);
+        expect(req1Resolved).toBe(true);
+        expect(req2Resolved).toBe(false);
+
+        // finally, release the second call to markRequestAsSent and check that the second request completes
+        resolveMarkRequestAsSentCallback();
+        await req2;
+    });
+});

spec/unit/rust-crypto/OutgoingRequestProcessor.spec.ts

@@ -0,0 +1,180 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import MockHttpBackend from "matrix-mock-request";
+import { Mocked } from "jest-mock";
+import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-js";
+import {
+    KeysBackupRequest,
+    KeysClaimRequest,
+    KeysQueryRequest,
+    KeysUploadRequest,
+    RoomMessageRequest,
+    SignatureUploadRequest,
+    ToDeviceRequest,
+} from "@matrix-org/matrix-sdk-crypto-js";
+
+import { TypedEventEmitter } from "../../../src/models/typed-event-emitter";
+import { HttpApiEvent, HttpApiEventHandlerMap, MatrixHttpApi } from "../../../src";
+import { OutgoingRequestProcessor } from "../../../src/rust-crypto/OutgoingRequestProcessor";
+
+describe("OutgoingRequestProcessor", () => {
+    /** the OutgoingRequestProcessor implementation under test */
+    let processor: OutgoingRequestProcessor;
+
+    /** A mock http backend which processor is connected to */
+    let httpBackend: MockHttpBackend;
+
+    /** a mocked-up OlmMachine which processor is connected to */
+    let olmMachine: Mocked<RustSdkCryptoJs.OlmMachine>;
+
+    /** wait for a call to olmMachine.markRequestAsSent */
+    function awaitCallToMarkAsSent(): Promise<void> {
+        return new Promise((resolve, _reject) => {
+            olmMachine.markRequestAsSent.mockImplementationOnce(async () => {
+                resolve(undefined);
+            });
+        });
+    }
+
+    beforeEach(async () => {
+        httpBackend = new MockHttpBackend();
+
+        const dummyEventEmitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
+        const httpApi = new MatrixHttpApi(dummyEventEmitter, {
+            baseUrl: "https://example.com",
+            prefix: "/_matrix",
+            fetchFn: httpBackend.fetchFn as typeof global.fetch,
+            onlyData: true,
+        });
+
+        olmMachine = {
+            markRequestAsSent: jest.fn(),
+        } as unknown as Mocked<RustSdkCryptoJs.OlmMachine>;
+
+        processor = new OutgoingRequestProcessor(olmMachine, httpApi);
+    });
+
+    /* simple requests that map directly to the request body */
+    const tests: Array<[string, any, "POST" | "PUT", string]> = [
+        ["KeysUploadRequest", KeysUploadRequest, "POST", "https://example.com/_matrix/client/v3/keys/upload"],
+        ["KeysQueryRequest", KeysQueryRequest, "POST", "https://example.com/_matrix/client/v3/keys/query"],
+        ["KeysClaimRequest", KeysClaimRequest, "POST", "https://example.com/_matrix/client/v3/keys/claim"],
+        [
+            "SignatureUploadRequest",
+            SignatureUploadRequest,
+            "POST",
+            "https://example.com/_matrix/client/v3/keys/signatures/upload",
+        ],
+        ["KeysBackupRequest", KeysBackupRequest, "PUT", "https://example.com/_matrix/client/v3/room_keys/keys"],
+    ];
+
+    test.each(tests)(`should handle %ss`, async (_, RequestClass, expectedMethod, expectedPath) => {
+        // first, mock up a request as we might expect to receive it from the Rust layer ...
+        const testBody = '{ "foo": "bar" }';
+        const outgoingRequest = new RequestClass("1234", testBody);
+
+        // ... then poke it into the OutgoingRequestProcessor under test.
+        const reqProm = processor.makeOutgoingRequest(outgoingRequest);
+
+        // Now: check that it makes a matching HTTP request ...
+        const testResponse = '{ "result": 1 }';
+        httpBackend
+            .when(expectedMethod, "/_matrix")
+            .check((req) => {
+                expect(req.path).toEqual(expectedPath);
+                expect(req.rawData).toEqual(testBody);
+                expect(req.headers["Accept"]).toEqual("application/json");
+                expect(req.headers["Content-Type"]).toEqual("application/json");
+            })
+            .respond(200, testResponse, true);
+
+        // ... and that it calls OlmMachine.markAsSent.
+        const markSentCallPromise = awaitCallToMarkAsSent();
+        await httpBackend.flushAllExpected();
+
+        await Promise.all([reqProm, markSentCallPromise]);
+        expect(olmMachine.markRequestAsSent).toHaveBeenCalledWith("1234", outgoingRequest.type, testResponse);
+        httpBackend.verifyNoOutstandingRequests();
+    });
+
+    it("should handle ToDeviceRequests", async () => {
+        // first, mock up the ToDeviceRequest as we might expect to receive it from the Rust layer ...
+        const testBody = '{ "foo": "bar" }';
+        const outgoingRequest = new ToDeviceRequest("1234", "test/type", "test/txnid", testBody);
+
+        // ... then poke it into the OutgoingRequestProcessor under test.
+        const reqProm = processor.makeOutgoingRequest(outgoingRequest);
+
+        // Now: check that it makes a matching HTTP request ...
+        const testResponse = '{ "result": 1 }';
+        httpBackend
+            .when("PUT", "/_matrix")
+            .check((req) => {
+                expect(req.path).toEqual("https://example.com/_matrix/client/v3/sendToDevice/test%2Ftype/test%2Ftxnid");
+                expect(req.rawData).toEqual(testBody);
+                expect(req.headers["Accept"]).toEqual("application/json");
+                expect(req.headers["Content-Type"]).toEqual("application/json");
+            })
+            .respond(200, testResponse, true);
+
+        // ... and that it calls OlmMachine.markAsSent.
+        const markSentCallPromise = awaitCallToMarkAsSent();
+        await httpBackend.flushAllExpected();
+
+        await Promise.all([reqProm, markSentCallPromise]);
+        expect(olmMachine.markRequestAsSent).toHaveBeenCalledWith("1234", outgoingRequest.type, testResponse);
+        httpBackend.verifyNoOutstandingRequests();
+    });
+
+    it("should handle RoomMessageRequests", async () => {
+        // first, mock up the RoomMessageRequest as we might expect to receive it from the Rust layer ...
+        const testBody = '{ "foo": "bar" }';
+        const outgoingRequest = new RoomMessageRequest("1234", "test/room", "test/txnid", "test/type", testBody);
+
+        // ... then poke it into the OutgoingRequestProcessor under test.
+        const reqProm = processor.makeOutgoingRequest(outgoingRequest);
+
+        // Now: check that it makes a matching HTTP request ...
+        const testResponse = '{ "result": 1 }';
+        httpBackend
+            .when("PUT", "/_matrix")
+            .check((req) => {
+                expect(req.path).toEqual(
+                    "https://example.com/_matrix/client/v3/room/test%2Froom/send/test%2Ftype/test%2Ftxnid",
+                );
+                expect(req.rawData).toEqual(testBody);
+                expect(req.headers["Accept"]).toEqual("application/json");
+                expect(req.headers["Content-Type"]).toEqual("application/json");
+            })
+            .respond(200, testResponse, true);
+
+        // ... and that it calls OlmMachine.markAsSent.
+        const markSentCallPromise = awaitCallToMarkAsSent();
+        await httpBackend.flushAllExpected();
+
+        await Promise.all([reqProm, markSentCallPromise]);
+        expect(olmMachine.markRequestAsSent).toHaveBeenCalledWith("1234", outgoingRequest.type, testResponse);
+        httpBackend.verifyNoOutstandingRequests();
+    });
+
+    it("does not explode with unknown requests", async () => {
+        const outgoingRequest = { id: "5678", type: 987 };
+        const markSentCallPromise = awaitCallToMarkAsSent();
+        await Promise.all([processor.makeOutgoingRequest(outgoingRequest), markSentCallPromise]);
+        expect(olmMachine.markRequestAsSent).toHaveBeenCalledWith("5678", 987, "");
+    });
+});

spec/unit/rust-crypto/rust-crypto.spec.ts

@@ -17,21 +17,16 @@ limitations under the License.
 import "fake-indexeddb/auto";
 import { IDBFactory } from "fake-indexeddb";
 import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-js";
-import {
-    KeysBackupRequest,
-    KeysClaimRequest,
-    KeysQueryRequest,
-    KeysUploadRequest,
-    OlmMachine,
-    SignatureUploadRequest,
-} from "@matrix-org/matrix-sdk-crypto-js";
+import { KeysQueryRequest, OlmMachine } from "@matrix-org/matrix-sdk-crypto-js";
 import { Mocked } from "jest-mock";
-import MockHttpBackend from "matrix-mock-request";
 
-import { RustCrypto } from "../../src/rust-crypto/rust-crypto";
-import { initRustCrypto } from "../../src/rust-crypto";
-import { HttpApiEvent, HttpApiEventHandlerMap, IToDeviceEvent, MatrixClient, MatrixHttpApi } from "../../src";
-import { TypedEventEmitter } from "../../src/models/typed-event-emitter";
+import { RustCrypto } from "../../../src/rust-crypto/rust-crypto";
+import { initRustCrypto } from "../../../src/rust-crypto";
+import { IToDeviceEvent, MatrixClient, MatrixHttpApi } from "../../../src";
+import { mkEvent } from "../../test-utils/test-utils";
+import { CryptoBackend } from "../../../src/common-crypto/CryptoBackend";
+import { IEventDecryptionResult } from "../../../src/@types/crypto";
+import { OutgoingRequestProcessor } from "../../../src/rust-crypto/OutgoingRequestProcessor";
 
 afterEach(() => {
     // reset fake-indexeddb after each test, to make sure we don't leak connections
@@ -103,8 +98,8 @@ describe("RustCrypto", () => {
         /** the RustCrypto implementation under test */
         let rustCrypto: RustCrypto;
 
-        /** A mock http backend which rustCrypto is connected to */
-        let httpBackend: MockHttpBackend;
+        /** A mock OutgoingRequestProcessor which rustCrypto is connected to */
+        let outgoingRequestProcessor: Mocked<OutgoingRequestProcessor>;
 
         /** a mocked-up OlmMachine which rustCrypto is connected to */
         let olmMachine: Mocked<RustSdkCryptoJs.OlmMachine>;
@@ -113,28 +108,25 @@ describe("RustCrypto", () => {
          *  the front of the queue, until it is empty. */
         let outgoingRequestQueue: Array<Array<any>>;
 
-        /** wait for a call to olmMachine.markRequestAsSent */
-        function awaitCallToMarkAsSent(): Promise<void> {
-            return new Promise((resolve, _reject) => {
-                olmMachine.markRequestAsSent.mockImplementationOnce(async () => {
-                    resolve(undefined);
+        /** wait for a call to outgoingRequestProcessor.makeOutgoingRequest.
+         *
+         * The promise resolves to a callback: the makeOutgoingRequest call will not complete until the returned
+         * callback is called.
+         */
+        function awaitCallToMakeOutgoingRequest(): Promise<() => void> {
+            return new Promise<() => void>((resolveCalledPromise, _reject) => {
+                outgoingRequestProcessor.makeOutgoingRequest.mockImplementationOnce(async () => {
+                    const completePromise = new Promise<void>((resolveCompletePromise, _reject) => {
+                        resolveCalledPromise(resolveCompletePromise);
+                    });
+                    return completePromise;
                 });
             });
         }
 
         beforeEach(async () => {
-            httpBackend = new MockHttpBackend();
-
             await RustSdkCryptoJs.initAsync();
 
-            const dummyEventEmitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-            const httpApi = new MatrixHttpApi(dummyEventEmitter, {
-                baseUrl: "https://example.com",
-                prefix: "/_matrix",
-                fetchFn: httpBackend.fetchFn as typeof global.fetch,
-                onlyData: true,
-            });
-
             // for these tests we use a mock OlmMachine, with an implementation of outgoingRequests that
             // returns objects from outgoingRequestQueue
             outgoingRequestQueue = [];
@@ -142,91 +134,55 @@ describe("RustCrypto", () => {
                 outgoingRequests: jest.fn().mockImplementation(() => {
                     return Promise.resolve(outgoingRequestQueue.shift() ?? []);
                 }),
-                markRequestAsSent: jest.fn(),
                 close: jest.fn(),
             } as unknown as Mocked<RustSdkCryptoJs.OlmMachine>;
 
-            rustCrypto = new RustCrypto(olmMachine, httpApi, TEST_USER, TEST_DEVICE_ID);
+            outgoingRequestProcessor = {
+                makeOutgoingRequest: jest.fn(),
+            } as unknown as Mocked<OutgoingRequestProcessor>;
+
+            rustCrypto = new RustCrypto(olmMachine, {} as MatrixHttpApi<any>, TEST_USER, TEST_DEVICE_ID);
+            rustCrypto["outgoingRequestProcessor"] = outgoingRequestProcessor;
         });
 
-        it("should poll for outgoing messages", () => {
+        it("should poll for outgoing messages and send them", async () => {
+            const testReq = new KeysQueryRequest("1234", "{}");
+            outgoingRequestQueue.push([testReq]);
+
+            const makeRequestPromise = awaitCallToMakeOutgoingRequest();
             rustCrypto.onSyncCompleted({});
+
+            await makeRequestPromise;
             expect(olmMachine.outgoingRequests).toHaveBeenCalled();
-        });
-
-        /* simple requests that map directly to the request body */
-        const tests: Array<[any, "POST" | "PUT", string]> = [
-            [KeysUploadRequest, "POST", "https://example.com/_matrix/client/v3/keys/upload"],
-            [KeysQueryRequest, "POST", "https://example.com/_matrix/client/v3/keys/query"],
-            [KeysClaimRequest, "POST", "https://example.com/_matrix/client/v3/keys/claim"],
-            [SignatureUploadRequest, "POST", "https://example.com/_matrix/client/v3/keys/signatures/upload"],
-            [KeysBackupRequest, "PUT", "https://example.com/_matrix/client/v3/room_keys/keys"],
-        ];
-
-        for (const [RequestClass, expectedMethod, expectedPath] of tests) {
-            it(`should handle ${RequestClass.name}s`, async () => {
-                const testBody = '{ "foo": "bar" }';
-                const outgoingRequest = new RequestClass("1234", testBody);
-                outgoingRequestQueue.push([outgoingRequest]);
-
-                const testResponse = '{ "result": 1 }';
-                httpBackend
-                    .when(expectedMethod, "/_matrix")
-                    .check((req) => {
-                        expect(req.path).toEqual(expectedPath);
-                        expect(req.rawData).toEqual(testBody);
-                        expect(req.headers["Accept"]).toEqual("application/json");
-                        expect(req.headers["Content-Type"]).toEqual("application/json");
-                    })
-                    .respond(200, testResponse, true);
-
-                rustCrypto.onSyncCompleted({});
-
-                expect(olmMachine.outgoingRequests).toHaveBeenCalledTimes(1);
-
-                const markSentCallPromise = awaitCallToMarkAsSent();
-                await httpBackend.flushAllExpected();
-
-                await markSentCallPromise;
-                expect(olmMachine.markRequestAsSent).toHaveBeenCalledWith("1234", outgoingRequest.type, testResponse);
-                httpBackend.verifyNoOutstandingRequests();
-            });
-        }
-
-        it("does not explode with unknown requests", async () => {
-            const outgoingRequest = { id: "5678", type: 987 };
-            outgoingRequestQueue.push([outgoingRequest]);
-
-            rustCrypto.onSyncCompleted({});
-
-            await awaitCallToMarkAsSent();
-            expect(olmMachine.markRequestAsSent).toHaveBeenCalledWith("5678", 987, "");
+            expect(outgoingRequestProcessor.makeOutgoingRequest).toHaveBeenCalledWith(testReq);
         });
 
         it("stops looping when stop() is called", async () => {
-            const testResponse = '{ "result": 1 }';
-
             for (let i = 0; i < 5; i++) {
                 outgoingRequestQueue.push([new KeysQueryRequest("1234", "{}")]);
-                httpBackend.when("POST", "/_matrix").respond(200, testResponse, true);
             }
 
+            let makeRequestPromise = awaitCallToMakeOutgoingRequest();
+
             rustCrypto.onSyncCompleted({});
 
             expect(rustCrypto["outgoingRequestLoopRunning"]).toBeTruthy();
 
             // go a couple of times round the loop
-            await httpBackend.flush("/_matrix", 1);
-            await awaitCallToMarkAsSent();
+            let resolveMakeRequest = await makeRequestPromise;
+            makeRequestPromise = awaitCallToMakeOutgoingRequest();
+            resolveMakeRequest();
 
-            await httpBackend.flush("/_matrix", 1);
-            await awaitCallToMarkAsSent();
+            resolveMakeRequest = await makeRequestPromise;
+            makeRequestPromise = awaitCallToMakeOutgoingRequest();
+            resolveMakeRequest();
 
             // a second sync while this is going on shouldn't make any difference
             rustCrypto.onSyncCompleted({});
 
-            await httpBackend.flush("/_matrix", 1);
-            await awaitCallToMarkAsSent();
+            resolveMakeRequest = await makeRequestPromise;
+            outgoingRequestProcessor.makeOutgoingRequest.mockReset();
+            resolveMakeRequest();
 
             // now stop...
             rustCrypto.stop();
@@ -238,11 +194,40 @@ describe("RustCrypto", () => {
                 setTimeout(resolve, 100);
             });
             expect(rustCrypto["outgoingRequestLoopRunning"]).toBeFalsy();
-            httpBackend.verifyNoOutstandingRequests();
+            expect(outgoingRequestProcessor.makeOutgoingRequest).not.toHaveBeenCalled();
             expect(olmMachine.outgoingRequests).not.toHaveBeenCalled();
 
             // we sent three, so there should be 2 left
             expect(outgoingRequestQueue.length).toEqual(2);
         });
     });
+
+    describe(".getEventEncryptionInfo", () => {
+        let rustCrypto: RustCrypto;
+
+        beforeEach(async () => {
+            const mockHttpApi = {} as MatrixClient["http"];
+            rustCrypto = (await initRustCrypto(mockHttpApi, TEST_USER, TEST_DEVICE_ID)) as RustCrypto;
+        });
+
+        it("should handle unencrypted events", () => {
+            const event = mkEvent({ event: true, type: "m.room.message", content: { body: "xyz" } });
+            const res = rustCrypto.getEventEncryptionInfo(event);
+            expect(res.encrypted).toBeFalsy();
+        });
+
+        it("should handle encrypted events", async () => {
+            const event = mkEvent({ event: true, type: "m.room.encrypted", content: { algorithm: "fake_alg" } });
+            const mockCryptoBackend = {
+                decryptEvent: () =>
+                    ({
+                        senderCurve25519Key: "1234",
+                    } as IEventDecryptionResult),
+            } as unknown as CryptoBackend;
+            await event.attemptDecryption(mockCryptoBackend);
+
+            const res = rustCrypto.getEventEncryptionInfo(event);
+            expect(res.encrypted).toBeTruthy();
+        });
+    });
 });

spec/unit/utils.spec.ts

@@ -1,3 +1,19 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
 import * as utils from "../../src/utils";
 import {
     alphabetPad,
@@ -587,4 +603,22 @@ describe("utils", function () {
             expect(utils.isSupportedReceiptType("this is a receipt type")).toBeFalsy();
         });
     });
+
+    describe("sleep", () => {
+        it("resolves", async () => {
+            await utils.sleep(0);
+        });
+
+        it("resolves with the provided value", async () => {
+            const expected = Symbol("hi");
+            const result = await utils.sleep(0, expected);
+            expect(result).toBe(expected);
+        });
+    });
+
+    describe("immediate", () => {
+        it("resolves", async () => {
+            await utils.immediate();
+        });
+    });
 });

spec/unit/webrtc/call.spec.ts

@@ -40,7 +40,9 @@ import {
     MockMediaStreamTrack,
     installWebRTCMocks,
     MockRTCPeerConnection,
+    MockRTCRtpTransceiver,
     SCREENSHARE_STREAM_ID,
+    MockRTCRtpSender,
 } from "../../test-utils/webrtc";
 import { CallFeed } from "../../../src/webrtc/callFeed";
 import { EventType, IContent, ISendEventResponse, MatrixEvent, Room } from "../../../src";
@@ -536,8 +538,15 @@ describe("Call", function () {
         it("if local video", async () => {
             call.getOpponentMember = jest.fn().mockReturnValue({ userId: "@bob:bar.uk" });
 
+            // since this is testing for the presence of a local sender, we need to add a transciever
+            // rather than just a source track
+            const mockTrack = new MockMediaStreamTrack("track_id", "video");
+            const mockTransceiver = new MockRTCRtpTransceiver(call.peerConn as unknown as MockRTCPeerConnection);
+            mockTransceiver.sender = new MockRTCRtpSender(mockTrack) as unknown as RTCRtpSender;
+            (call as any).transceivers.set("m.usermedia:video", mockTransceiver);
+
             (call as any).pushNewLocalFeed(
-                new MockMediaStream("remote_stream1", [new MockMediaStreamTrack("track_id", "video")]),
+                new MockMediaStream("remote_stream1", [mockTrack]),
                 SDPStreamMetadataPurpose.Usermedia,
                 false,
             );
@@ -829,6 +838,55 @@ describe("Call", function () {
             await startVideoCall(client, call);
         });
 
+        afterEach(() => {
+            jest.useRealTimers();
+        });
+
+        it("should not remove video sender on video mute", async () => {
+            await call.setLocalVideoMuted(true);
+            expect((call as any).hasUserMediaVideoSender).toBe(true);
+        });
+
+        it("should release camera after short delay on video mute", async () => {
+            jest.useFakeTimers();
+
+            await call.setLocalVideoMuted(true);
+
+            jest.advanceTimersByTime(500);
+
+            expect(call.hasLocalUserMediaVideoTrack).toBe(false);
+        });
+
+        it("should re-request video feed on video unmute if it doesn't have one", async () => {
+            jest.useFakeTimers();
+
+            const mockGetUserMediaStream = jest
+                .fn()
+                .mockReturnValue(client.client.getMediaHandler().getUserMediaStream(true, true));
+
+            client.client.getMediaHandler().getUserMediaStream = mockGetUserMediaStream;
+
+            await call.setLocalVideoMuted(true);
+
+            jest.advanceTimersByTime(500);
+
+            await call.setLocalVideoMuted(false);
+
+            expect(mockGetUserMediaStream).toHaveBeenCalled();
+        });
+
+        it("should not release camera on fast mute and unmute", async () => {
+            const mockGetUserMediaStream = jest.fn();
+
+            client.client.getMediaHandler().getUserMediaStream = mockGetUserMediaStream;
+
+            await call.setLocalVideoMuted(true);
+            await call.setLocalVideoMuted(false);
+
+            expect(mockGetUserMediaStream).not.toHaveBeenCalled();
+            expect(call.hasLocalUserMediaVideoTrack).toBe(true);
+        });
+
         describe("sending sdp_stream_metadata_changed events", () => {
             it("should send sdp_stream_metadata_changed when muting audio", async () => {
                 await call.setMicrophoneMuted(true);
@@ -1385,7 +1443,7 @@ describe("Call", function () {
                 }),
             );
             // @ts-ignore Mock
-            expect(call.terminate).toHaveBeenCalledWith(CallParty.Local, CallErrorCode.Transfered, true);
+            expect(call.terminate).toHaveBeenCalledWith(CallParty.Local, CallErrorCode.Transferred, true);
         });
     });
 

src/@types/beacon.ts

@@ -14,8 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { RELATES_TO_RELATIONSHIP, REFERENCE_RELATION } from "matrix-events-sdk";
-
+import { RelatesToRelationship, REFERENCE_RELATION } from "./extensible_events";
 import { UnstableValue } from "../NamespacedValue";
 import { MAssetEvent, MLocationEvent, MTimestampEvent } from "./location";
 
@@ -138,4 +137,4 @@ export type MBeaconEventContent = MLocationEvent &
     // timestamp when location was taken
     MTimestampEvent &
     // relates to a beacon_info event
-    RELATES_TO_RELATIONSHIP<typeof REFERENCE_RELATION>;
+    RelatesToRelationship<typeof REFERENCE_RELATION>;

src/@types/event.ts

@@ -33,6 +33,7 @@ export enum EventType {
     RoomGuestAccess = "m.room.guest_access",
     RoomServerAcl = "m.room.server_acl",
     RoomTombstone = "m.room.tombstone",
+    RoomPredecessor = "org.matrix.msc3946.room_predecessor",
 
     SpaceChild = "m.space.child",
     SpaceParent = "m.space.parent",

src/@types/extensible_events.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2021 The Matrix.org Foundation C.I.C.
+Copyright 2021 - 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -14,8 +14,138 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-// Types for MSC1767: Extensible events in Matrix
+import { EitherAnd, NamespacedValue, Optional, UnstableValue } from "matrix-events-sdk";
 
-import { UnstableValue } from "../NamespacedValue";
+import { isProvided } from "../extensible_events_v1/utilities";
 
-export const TEXT_NODE_TYPE = new UnstableValue("m.text", "org.matrix.msc1767.text");
+// Types and utilities for MSC1767: Extensible events (version 1) in Matrix
+
+/**
+ * Represents the stable and unstable values of a given namespace.
+ */
+export type TSNamespace<N> = N extends NamespacedValue<infer S, infer U>
+    ? TSNamespaceValue<S> | TSNamespaceValue<U>
+    : never;
+
+/**
+ * Represents a namespaced value, if the value is a string. Used to extract provided types
+ * from a TSNamespace<N> (in cases where only stable *or* unstable is provided).
+ */
+export type TSNamespaceValue<V> = V extends string ? V : never;
+
+/**
+ * Creates a type which is V when T is `never`, otherwise T.
+ */
+// See https://github.com/microsoft/TypeScript/issues/23182#issuecomment-379091887 for details on the array syntax.
+export type DefaultNever<T, V> = [T] extends [never] ? V : T;
+
+/**
+ * The namespaced value for m.message
+ */
+export const M_MESSAGE = new UnstableValue("m.message", "org.matrix.msc1767.message");
+
+/**
+ * An m.message event rendering
+ */
+export interface IMessageRendering {
+    body: string;
+    mimetype?: string;
+}
+
+/**
+ * The content for an m.message event
+ */
+export type ExtensibleMessageEventContent = EitherAnd<
+    { [M_MESSAGE.name]: IMessageRendering[] },
+    { [M_MESSAGE.altName]: IMessageRendering[] }
+>;
+
+/**
+ * The namespaced value for m.text
+ */
+export const M_TEXT = new UnstableValue("m.text", "org.matrix.msc1767.text");
+
+/**
+ * The content for an m.text event
+ */
+export type TextEventContent = EitherAnd<{ [M_TEXT.name]: string }, { [M_TEXT.altName]: string }>;
+
+/**
+ * The namespaced value for m.html
+ */
+export const M_HTML = new UnstableValue("m.html", "org.matrix.msc1767.html");
+
+/**
+ * The content for an m.html event
+ */
+export type HtmlEventContent = EitherAnd<{ [M_HTML.name]: string }, { [M_HTML.altName]: string }>;
+
+/**
+ * The content for an m.message, m.text, or m.html event
+ */
+export type ExtensibleAnyMessageEventContent = ExtensibleMessageEventContent | TextEventContent | HtmlEventContent;
+
+/**
+ * The namespaced value for an m.reference relation
+ */
+export const REFERENCE_RELATION = new NamespacedValue("m.reference");
+
+/**
+ * Represents any relation type
+ */
+export type AnyRelation = TSNamespace<typeof REFERENCE_RELATION> | string;
+
+/**
+ * An m.relates_to relationship
+ */
+export type RelatesToRelationship<R = never, C = never> = {
+    "m.relates_to": {
+        // See https://github.com/microsoft/TypeScript/issues/23182#issuecomment-379091887 for array syntax
+        rel_type: [R] extends [never] ? AnyRelation : TSNamespace<R>;
+        event_id: string;
+    } & DefaultNever<C, {}>;
+};
+
+/**
+ * Partial types for a Matrix Event.
+ */
+export interface IPartialEvent<TContent> {
+    type: string;
+    content: TContent;
+}
+
+/**
+ * Represents a potentially namespaced event type.
+ */
+export type ExtensibleEventType = NamespacedValue<string, string> | string;
+
+/**
+ * Determines if two event types are the same, including namespaces.
+ * @param given - The given event type. This will be compared
+ * against the expected type.
+ * @param expected - The expected event type.
+ * @returns True if the given type matches the expected type.
+ */
+export function isEventTypeSame(
+    given: Optional<ExtensibleEventType>,
+    expected: Optional<ExtensibleEventType>,
+): boolean {
+    if (typeof given === "string") {
+        if (typeof expected === "string") {
+            return expected === given;
+        } else {
+            return (expected as NamespacedValue<string, string>).matches(given as string);
+        }
+    } else {
+        if (typeof expected === "string") {
+            return (given as NamespacedValue<string, string>).matches(expected as string);
+        } else {
+            const expectedNs = expected as NamespacedValue<string, string>;
+            const givenNs = given as NamespacedValue<string, string>;
+            return (
+                expectedNs.matches(givenNs.name) ||
+                (isProvided(givenNs.altName) && expectedNs.matches(givenNs.altName!))
+            );
+        }
+    }
+}

src/@types/location.ts

@@ -18,7 +18,7 @@ limitations under the License.
 import { EitherAnd } from "matrix-events-sdk";
 
 import { UnstableValue } from "../NamespacedValue";
-import { TEXT_NODE_TYPE } from "./extensible_events";
+import { M_TEXT } from "./extensible_events";
 
 export enum LocationAssetType {
     Self = "m.self",
@@ -50,7 +50,7 @@ export type MLocationEvent = EitherAnd<
     { [M_LOCATION.altName]: MLocationContent }
 >;
 
-export type MTextEvent = EitherAnd<{ [TEXT_NODE_TYPE.name]: string }, { [TEXT_NODE_TYPE.altName]: string }>;
+export type MTextEvent = EitherAnd<{ [M_TEXT.name]: string }, { [M_TEXT.altName]: string }>;
 
 /* From the spec at:
  * https://github.com/matrix-org/matrix-doc/blob/matthew/location/proposals/3488-location.md

src/@types/polls.ts

@@ -0,0 +1,119 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { EitherAnd, UnstableValue } from "matrix-events-sdk";
+
+import {
+    ExtensibleAnyMessageEventContent,
+    REFERENCE_RELATION,
+    RelatesToRelationship,
+    TSNamespace,
+} from "./extensible_events";
+
+/**
+ * Identifier for a disclosed poll.
+ */
+export const M_POLL_KIND_DISCLOSED = new UnstableValue("m.poll.disclosed", "org.matrix.msc3381.poll.disclosed");
+
+/**
+ * Identifier for an undisclosed poll.
+ */
+export const M_POLL_KIND_UNDISCLOSED = new UnstableValue("m.poll.undisclosed", "org.matrix.msc3381.poll.undisclosed");
+
+/**
+ * Any poll kind.
+ */
+export type PollKind = TSNamespace<typeof M_POLL_KIND_DISCLOSED> | TSNamespace<typeof M_POLL_KIND_UNDISCLOSED> | string;
+
+/**
+ * Known poll kind namespaces.
+ */
+export type KnownPollKind = typeof M_POLL_KIND_DISCLOSED | typeof M_POLL_KIND_UNDISCLOSED;
+
+/**
+ * The namespaced value for m.poll.start
+ */
+export const M_POLL_START = new UnstableValue("m.poll.start", "org.matrix.msc3381.poll.start");
+
+/**
+ * The m.poll.start type within event content
+ */
+export type PollStartSubtype = {
+    question: ExtensibleAnyMessageEventContent;
+    kind: PollKind;
+    max_selections?: number; // default 1, always positive
+    answers: PollAnswer[];
+};
+
+/**
+ * A poll answer.
+ */
+export type PollAnswer = ExtensibleAnyMessageEventContent & { id: string };
+
+/**
+ * The event definition for an m.poll.start event (in content)
+ */
+export type PollStartEvent = EitherAnd<
+    { [M_POLL_START.name]: PollStartSubtype },
+    { [M_POLL_START.altName]: PollStartSubtype }
+>;
+
+/**
+ * The content for an m.poll.start event
+ */
+export type PollStartEventContent = PollStartEvent & ExtensibleAnyMessageEventContent;
+
+/**
+ * The namespaced value for m.poll.response
+ */
+export const M_POLL_RESPONSE = new UnstableValue("m.poll.response", "org.matrix.msc3381.poll.response");
+
+/**
+ * The m.poll.response type within event content
+ */
+export type PollResponseSubtype = {
+    answers: string[];
+};
+
+/**
+ * The event definition for an m.poll.response event (in content)
+ */
+export type PollResponseEvent = EitherAnd<
+    { [M_POLL_RESPONSE.name]: PollResponseSubtype },
+    { [M_POLL_RESPONSE.altName]: PollResponseSubtype }
+>;
+
+/**
+ * The content for an m.poll.response event
+ */
+export type PollResponseEventContent = PollResponseEvent & RelatesToRelationship<typeof REFERENCE_RELATION>;
+
+/**
+ * The namespaced value for m.poll.end
+ */
+export const M_POLL_END = new UnstableValue("m.poll.end", "org.matrix.msc3381.poll.end");
+
+/**
+ * The event definition for an m.poll.end event (in content)
+ */
+export type PollEndEvent = EitherAnd<{ [M_POLL_END.name]: {} }, { [M_POLL_END.altName]: {} }>;
+
+/**
+ * The content for an m.poll.end event
+ */
+export type PollEndEventContent = PollEndEvent &
+    RelatesToRelationship<typeof REFERENCE_RELATION> &
+    ExtensibleAnyMessageEventContent;

src/@types/topic.ts

@@ -14,9 +14,10 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { EitherAnd, IMessageRendering } from "matrix-events-sdk";
+import { EitherAnd } from "matrix-events-sdk";
 
 import { UnstableValue } from "../NamespacedValue";
+import { IMessageRendering } from "./extensible_events";
 
 /**
  * Extensible topic event type based on MSC3765

src/autodiscovery.ts

@@ -47,7 +47,7 @@ interface WellKnownConfig extends Omit<IWellKnownConfig, "error"> {
     error?: IWellKnownConfig["error"] | null;
 }
 
-interface ClientConfig extends Omit<IClientWellKnown, "m.homeserver" | "m.identity_server"> {
+export interface ClientConfig extends Omit<IClientWellKnown, "m.homeserver" | "m.identity_server"> {
     "m.homeserver": WellKnownConfig;
     "m.identity_server": WellKnownConfig;
 }

src/client.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2015-2022 The Matrix.org Foundation C.I.C.
+Copyright 2015-2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -209,7 +209,6 @@ import { ToDeviceBatch } from "./models/ToDeviceMessage";
 import { IgnoredInvites } from "./models/invites-ignorer";
 import { UIARequest, UIAResponse } from "./@types/uia";
 import { LocalNotificationSettings } from "./@types/local_notifications";
-import { UNREAD_THREAD_NOTIFICATIONS } from "./@types/sync";
 import { buildFeatureSupportMap, Feature, ServerSupport } from "./feature";
 import { CryptoBackend } from "./common-crypto/CryptoBackend";
 import { RUST_SDK_STORE_PREFIX } from "./rust-crypto/constants";
@@ -446,10 +445,16 @@ export interface IStartClientOpts {
     clientWellKnownPollPeriod?: number;
 
     /**
-     * @experimental
+     * @deprecated use `threadSupport` instead
      */
     experimentalThreadSupport?: boolean;
 
+    /**
+     * Will organises events in threaded conversations when
+     * a thread relation is encountered
+     */
+    threadSupport?: boolean;
+
     /**
      * @experimental
      */
@@ -568,6 +573,8 @@ export interface IWellKnownConfig {
     error?: Error | string;
     // eslint-disable-next-line
     base_url?: string | null;
+    // XXX: this is undocumented
+    server_name?: string;
 }
 
 export interface IDelegatedAuthConfig {
@@ -855,6 +862,7 @@ export enum ClientEvent {
     SyncUnexpectedError = "sync.unexpectedError",
     ClientWellKnown = "WellKnown.client",
     ReceivedVoipEvent = "received_voip_event",
+    UndecryptableToDeviceEvent = "toDeviceEvent.undecryptable",
     TurnServers = "turnServers",
     TurnServersError = "turnServers.error",
 }
@@ -1063,6 +1071,18 @@ export type ClientEventHandlerMap = {
      * ```
      */
     [ClientEvent.ToDeviceEvent]: (event: MatrixEvent) => void;
+    /**
+     * Fires if a to-device event is received that cannot be decrypted.
+     * Encrypted to-device events will (generally) use plain Olm encryption,
+     * in which case decryption failures are fatal: the event will never be
+     * decryptable, unlike Megolm encrypted events where the key may simply
+     * arrive later.
+     *
+     * An undecryptable to-device event is therefore likley to indicate problems.
+     *
+     * @param event - The undecyptable to-device event
+     */
+    [ClientEvent.UndecryptableToDeviceEvent]: (event: MatrixEvent) => void;
     /**
      * Fires whenever new user-scoped account_data is added.
      * @param event - The event describing the account_data just added
@@ -1435,6 +1455,19 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             this.syncApi = new SyncApi(this, this.clientOpts, this.buildSyncApiOptions());
         }
 
+        if (this.clientOpts.hasOwnProperty("experimentalThreadSupport")) {
+            logger.warn("`experimentalThreadSupport` has been deprecated, use `threadSupport` instead");
+        }
+
+        // If `threadSupport` is omitted and the deprecated `experimentalThreadSupport` has been passed
+        // We should fallback to that value for backwards compatibility purposes
+        if (
+            !this.clientOpts.hasOwnProperty("threadSupport") &&
+            this.clientOpts.hasOwnProperty("experimentalThreadSupport")
+        ) {
+            this.clientOpts.threadSupport = this.clientOpts.experimentalThreadSupport;
+        }
+
         this.syncApi.sync();
 
         if (this.clientOpts.clientWellKnownPollPeriod !== undefined) {
@@ -2152,7 +2185,11 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         // importing rust-crypto will download the webassembly, so we delay it until we know it will be
         // needed.
         const RustCrypto = await import("./rust-crypto");
-        this.cryptoBackend = await RustCrypto.initRustCrypto(this.http, userId, deviceId);
+        const rustCrypto = await RustCrypto.initRustCrypto(this.http, userId, deviceId);
+        this.cryptoBackend = rustCrypto;
+
+        // attach the event listeners needed by RustCrypto
+        this.on(RoomMemberEvent.Membership, rustCrypto.onRoomMembership.bind(rustCrypto));
     }
 
     /**
@@ -2494,10 +2531,10 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns
      */
     public checkUserTrust(userId: string): UserTrustLevel {
-        if (!this.crypto) {
+        if (!this.cryptoBackend) {
             throw new Error("End-to-end encryption disabled");
         }
-        return this.crypto.checkUserTrust(userId);
+        return this.cryptoBackend.checkUserTrust(userId);
     }
 
     /**
@@ -2509,10 +2546,10 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @param deviceId - The ID of the device to check
      */
     public checkDeviceTrust(userId: string, deviceId: string): DeviceTrustLevel {
-        if (!this.crypto) {
+        if (!this.cryptoBackend) {
             throw new Error("End-to-end encryption disabled");
         }
-        return this.crypto.checkDeviceTrust(userId, deviceId);
+        return this.cryptoBackend.checkDeviceTrust(userId, deviceId);
     }
 
     /**
@@ -2575,10 +2612,10 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @param room - the room the event is in
      */
     public prepareToEncrypt(room: Room): void {
-        if (!this.crypto) {
+        if (!this.cryptoBackend) {
             throw new Error("End-to-end encryption disabled");
         }
-        this.crypto.prepareToEncrypt(room);
+        this.cryptoBackend.prepareToEncrypt(room);
     }
 
     /**
@@ -2676,10 +2713,10 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns The event information.
      */
     public getEventEncryptionInfo(event: MatrixEvent): IEncryptedEventInfo {
-        if (!this.crypto) {
+        if (!this.cryptoBackend) {
             throw new Error("End-to-end encryption disabled");
         }
-        return this.crypto.getEventEncryptionInfo(event);
+        return this.cryptoBackend.getEventEncryptionInfo(event);
     }
 
     /**
@@ -3767,14 +3804,18 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * This is essentially getRooms() with some rooms filtered out, eg. old versions
      * of rooms that have been replaced or (in future) other rooms that have been
      * marked at the protocol level as not to be displayed to the user.
+     *
+     * @param msc3946ProcessDynamicPredecessor - if true, look for an
+     *                                           m.room.predecessor state event and
+     *                                           use it if found (MSC3946).
      * @returns A list of rooms, or an empty list if there is no data store.
      */
-    public getVisibleRooms(): Room[] {
+    public getVisibleRooms(msc3946ProcessDynamicPredecessor = false): Room[] {
         const allRooms = this.store.getRooms();
 
         const replacedRooms = new Set();
         for (const r of allRooms) {
-            const predecessor = r.findPredecessorRoomId();
+            const predecessor = r.findPredecessor(msc3946ProcessDynamicPredecessor)?.roomId;
             if (predecessor) {
                 replacedRooms.add(predecessor);
             }
@@ -4355,11 +4396,11 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             return null;
         }
 
-        if (!this.isRoomEncrypted(event.getRoomId()!)) {
+        if (!room || !this.isRoomEncrypted(event.getRoomId()!)) {
             return null;
         }
 
-        if (!this.crypto && this.usingExternalCrypto) {
+        if (!this.cryptoBackend && this.usingExternalCrypto) {
             // The client has opted to allow sending messages to encrypted
             // rooms even if the room is encrypted, and we haven't setup
             // crypto. This is useful for users of matrix-org/pantalaimon
@@ -4380,13 +4421,11 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             return null;
         }
 
-        if (!this.crypto) {
-            throw new Error(
-                "This room is configured to use encryption, but your client does " + "not support encryption.",
-            );
+        if (!this.cryptoBackend) {
+            throw new Error("This room is configured to use encryption, but your client does not support encryption.");
         }
 
-        return this.crypto.encryptEvent(event, room);
+        return this.cryptoBackend.encryptEvent(event, room);
     }
 
     /**
@@ -4804,8 +4843,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             $eventId: event.getId()!,
         });
 
-        const supportsThreadRR = this.canSupport.get(Feature.ThreadUnreadNotifications) !== ServerSupport.Unsupported;
-        if (supportsThreadRR && !unthreaded) {
+        if (!unthreaded) {
             const isThread = !!event.threadRootId;
             body = {
                 ...body,
@@ -4973,70 +5011,83 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * which can be proven to be linked. For example, rooms which have a create
      * event pointing to an old room which the client is not aware of or doesn't
      * have a matching tombstone would not be returned.
+     * @param msc3946ProcessDynamicPredecessor - if true, look for
+     * m.room.predecessor state events as well as create events, and prefer
+     * predecessor events where they exist (MSC3946).
      * @returns An array of rooms representing the upgrade
      * history.
      */
-    public getRoomUpgradeHistory(roomId: string, verifyLinks = false): Room[] {
-        let currentRoom = this.getRoom(roomId);
+    public getRoomUpgradeHistory(
+        roomId: string,
+        verifyLinks = false,
+        msc3946ProcessDynamicPredecessor = false,
+    ): Room[] {
+        const currentRoom = this.getRoom(roomId);
         if (!currentRoom) return [];
 
-        const upgradeHistory = [currentRoom];
+        const before = this.findPredecessorRooms(currentRoom, verifyLinks, msc3946ProcessDynamicPredecessor);
+        const after = this.findSuccessorRooms(currentRoom, verifyLinks, msc3946ProcessDynamicPredecessor);
 
-        // Work backwards first, looking at create events.
-        let createEvent = currentRoom.currentState.getStateEvents(EventType.RoomCreate, "");
-        while (createEvent) {
-            const predecessor = createEvent.getContent()["predecessor"];
-            if (predecessor && predecessor["room_id"]) {
-                const refRoom = this.getRoom(predecessor["room_id"]);
-                if (!refRoom) break; // end of the chain
+        return [...before, currentRoom, ...after];
+    }
 
-                if (verifyLinks) {
-                    const tombstone = refRoom.currentState.getStateEvents(EventType.RoomTombstone, "");
+    private findPredecessorRooms(room: Room, verifyLinks: boolean, msc3946ProcessDynamicPredecessor: boolean): Room[] {
+        const ret: Room[] = [];
 
-                    if (!tombstone || tombstone.getContent()["replacement_room"] !== refRoom.roomId) {
-                        break;
-                    }
-                }
-
-                // Insert at the front because we're working backwards from the currentRoom
-                upgradeHistory.splice(0, 0, refRoom);
-                createEvent = refRoom.currentState.getStateEvents(EventType.RoomCreate, "");
-            } else {
-                // No further create events to look at
+        // Work backwards from newer to older rooms
+        let predecessorRoomId = room.findPredecessor(msc3946ProcessDynamicPredecessor)?.roomId;
+        while (predecessorRoomId !== null) {
+            const predecessorRoom = this.getRoom(predecessorRoomId);
+            if (predecessorRoom === null) {
                 break;
             }
-        }
+            if (verifyLinks) {
+                const tombstone = predecessorRoom.currentState.getStateEvents(EventType.RoomTombstone, "");
+                if (!tombstone || tombstone.getContent()["replacement_room"] !== room.roomId) {
+                    break;
+                }
+            }
 
-        // Work forwards next, looking at tombstone events
-        let tombstoneEvent = currentRoom.currentState.getStateEvents(EventType.RoomTombstone, "");
+            // Insert at the front because we're working backwards from the currentRoom
+            ret.splice(0, 0, predecessorRoom);
+
+            room = predecessorRoom;
+            predecessorRoomId = room.findPredecessor(msc3946ProcessDynamicPredecessor)?.roomId;
+        }
+        return ret;
+    }
+
+    private findSuccessorRooms(room: Room, verifyLinks: boolean, msc3946ProcessDynamicPredecessor: boolean): Room[] {
+        const ret: Room[] = [];
+
+        // Work forwards, looking at tombstone events
+        let tombstoneEvent = room.currentState.getStateEvents(EventType.RoomTombstone, "");
         while (tombstoneEvent) {
-            const refRoom = this.getRoom(tombstoneEvent.getContent()["replacement_room"]);
-            if (!refRoom) break; // end of the chain
-            if (refRoom.roomId === currentRoom.roomId) break; // Tombstone is referencing it's own room
+            const successorRoom = this.getRoom(tombstoneEvent.getContent()["replacement_room"]);
+            if (!successorRoom) break; // end of the chain
+            if (successorRoom.roomId === room.roomId) break; // Tombstone is referencing its own room
 
             if (verifyLinks) {
-                createEvent = refRoom.currentState.getStateEvents(EventType.RoomCreate, "");
-                if (!createEvent || !createEvent.getContent()["predecessor"]) break;
-
-                const predecessor = createEvent.getContent()["predecessor"];
-                if (predecessor["room_id"] !== currentRoom.roomId) break;
+                const predecessorRoomId = successorRoom.findPredecessor(msc3946ProcessDynamicPredecessor)?.roomId;
+                if (!predecessorRoomId || predecessorRoomId !== room.roomId) {
+                    break;
+                }
             }
 
             // Push to the end because we're looking forwards
-            upgradeHistory.push(refRoom);
-            const roomIds = new Set(upgradeHistory.map((ref) => ref.roomId));
-            if (roomIds.size < upgradeHistory.length) {
+            ret.push(successorRoom);
+            const roomIds = new Set(ret.map((ref) => ref.roomId));
+            if (roomIds.size < ret.length) {
                 // The last room added to the list introduced a previous roomId
                 // To avoid recursion, return the last rooms - 1
-                return upgradeHistory.slice(0, upgradeHistory.length - 1);
+                return ret.slice(0, ret.length - 1);
             }
 
             // Set the current room to the reference room so we know where we're at
-            currentRoom = refRoom;
-            tombstoneEvent = currentRoom.currentState.getStateEvents(EventType.RoomTombstone, "");
+            room = successorRoom;
+            tombstoneEvent = room.currentState.getStateEvents(EventType.RoomTombstone, "");
         }
-
-        return upgradeHistory;
+        return ret;
     }
 
     /**
@@ -5407,7 +5458,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
                     const [timelineEvents, threadedEvents] = room.partitionThreadedEvents(matrixEvents);
 
-                    this.processBeaconEvents(room, timelineEvents);
+                    this.processAggregatedTimelineEvents(room, timelineEvents);
                     room.addEventsToTimeline(timelineEvents, true, room.getLiveTimeline());
                     this.processThreadEvents(room, threadedEvents, true);
 
@@ -5468,7 +5519,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             return timelineSet.getTimelineForEvent(eventId);
         }
 
-        if (timelineSet.thread && this.supportsExperimentalThreads()) {
+        if (timelineSet.thread && this.supportsThreads()) {
             return this.getThreadTimeline(timelineSet, eventId);
         }
 
@@ -5522,7 +5573,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         timelineSet.addEventsToTimeline(timelineEvents, true, timeline, res.start);
         // The target event is not in a thread but process the contextual events, so we can show any threads around it.
         this.processThreadEvents(timelineSet.room, threadedEvents, true);
-        this.processBeaconEvents(timelineSet.room, timelineEvents);
+        this.processAggregatedTimelineEvents(timelineSet.room, timelineEvents);
 
         // There is no guarantee that the event ended up in "timeline" (we might have switched to a neighbouring
         // timeline) - so check the room's index again. On the other hand, there's no guarantee the event ended up
@@ -5535,7 +5586,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     }
 
     public async getThreadTimeline(timelineSet: EventTimelineSet, eventId: string): Promise<EventTimeline | undefined> {
-        if (!this.supportsExperimentalThreads()) {
+        if (!this.supportsThreads()) {
             throw new Error("could not get thread timeline: no client support");
         }
 
@@ -5617,7 +5668,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                 }
                 timeline.setPaginationToken(resOlder.next_batch ?? null, Direction.Backward);
                 timeline.setPaginationToken(resNewer.next_batch ?? null, Direction.Forward);
-                this.processBeaconEvents(timelineSet.room, events);
+                this.processAggregatedTimelineEvents(timelineSet.room, events);
 
                 // There is no guarantee that the event ended up in "timeline" (we might have switched to a neighbouring
                 // timeline) - so check the room's index again. On the other hand, there's no guarantee the event ended up
@@ -5674,7 +5725,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                 }
                 timeline.setPaginationToken(resOlder.next_batch ?? null, Direction.Backward);
                 timeline.setPaginationToken(null, Direction.Forward);
-                this.processBeaconEvents(timelineSet.room, events);
+                this.processAggregatedTimelineEvents(timelineSet.room, events);
 
                 return timeline;
             }
@@ -5927,7 +5978,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                     // in the notification timeline set
                     const timelineSet = eventTimeline.getTimelineSet();
                     timelineSet.addEventsToTimeline(matrixEvents, backwards, eventTimeline, token);
-                    this.processBeaconEvents(timelineSet.room, matrixEvents);
+                    this.processAggregatedTimelineEvents(timelineSet.room, matrixEvents);
 
                     // if we've hit the end of the timeline, we need to stop trying to
                     // paginate. We need to keep the 'forwards' token though, to make sure
@@ -5969,7 +6020,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
                     const timelineSet = eventTimeline.getTimelineSet();
                     timelineSet.addEventsToTimeline(matrixEvents, backwards, eventTimeline, token);
-                    this.processBeaconEvents(room, matrixEvents);
+                    this.processAggregatedTimelineEvents(room, matrixEvents);
                     this.processThreadRoots(room, matrixEvents, backwards);
 
                     // if we've hit the end of the timeline, we need to stop trying to
@@ -6016,7 +6067,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                         const originalEvent = await this.fetchRoomEvent(eventTimeline.getRoomId() ?? "", thread.id);
                         timelineSet.addEventsToTimeline([mapper(originalEvent)], true, eventTimeline, null);
                     }
-                    this.processBeaconEvents(timelineSet.room, matrixEvents);
+                    this.processAggregatedTimelineEvents(timelineSet.room, matrixEvents);
 
                     // if we've hit the end of the timeline, we need to stop trying to
                     // paginate. We need to keep the 'forwards' token though, to make sure
@@ -6054,7 +6105,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                     const timelineSet = eventTimeline.getTimelineSet();
                     const [timelineEvents] = room.partitionThreadedEvents(matrixEvents);
                     timelineSet.addEventsToTimeline(timelineEvents, backwards, eventTimeline, token);
-                    this.processBeaconEvents(room, timelineEvents);
+                    this.processAggregatedTimelineEvents(room, timelineEvents);
                     this.processThreadRoots(
                         room,
                         timelineEvents.filter((it) => it.getServerAggregatedRelation(THREAD_RELATION_TYPE.name)),
@@ -6996,10 +7047,6 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         const serverVersions = await this.serverVersionsPromise;
         this.canSupport = await buildFeatureSupportMap(serverVersions);
 
-        // We can set flag values to use their stable or unstable version
-        const support = this.canSupport.get(Feature.ThreadUnreadNotifications);
-        UNREAD_THREAD_NOTIFICATIONS.setPreferUnstable(support === ServerSupport.Unstable);
-
         return this.serverVersionsPromise;
     }
 
@@ -9307,12 +9354,21 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     }
 
     /**
-     * @experimental
+     * @deprecated use supportsThreads() instead
      */
     public supportsExperimentalThreads(): boolean {
+        logger.warn(`supportsExperimentalThreads() is deprecated, use supportThreads() instead`);
         return this.clientOpts?.experimentalThreadSupport || false;
     }
 
+    /**
+     * A helper to determine thread support
+     * @returns a boolean to determine if threads are enabled
+     */
+    public supportsThreads(): boolean {
+        return this.clientOpts?.threadSupport || false;
+    }
+
     /**
      * Fetches the summary of a room as defined by an initial version of MSC3266 and implemented in Synapse
      * Proposed at https://github.com/matrix-org/matrix-doc/pull/3266
@@ -9327,24 +9383,42 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     }
 
     /**
-     * @experimental
+     * Processes a list of threaded events and adds them to their respective timelines
+     * @param room - the room the adds the threaded events
+     * @param threadedEvents - an array of the threaded events
+     * @param toStartOfTimeline - the direction in which we want to add the events
      */
     public processThreadEvents(room: Room, threadedEvents: MatrixEvent[], toStartOfTimeline: boolean): void {
         room.processThreadedEvents(threadedEvents, toStartOfTimeline);
     }
 
     /**
-     * @experimental
+     * Processes a list of thread roots and creates a thread model
+     * @param room - the room to create the threads in
+     * @param threadedEvents - an array of thread roots
+     * @param toStartOfTimeline - the direction
      */
     public processThreadRoots(room: Room, threadedEvents: MatrixEvent[], toStartOfTimeline: boolean): void {
         room.processThreadRoots(threadedEvents, toStartOfTimeline);
     }
 
     public processBeaconEvents(room?: Room, events?: MatrixEvent[]): void {
+        this.processAggregatedTimelineEvents(room, events);
+    }
+
+    /**
+     * Calls aggregation functions for event types that are aggregated
+     * Polls and location beacons
+     * @param room - room the events belong to
+     * @param events - timeline events to be processed
+     * @returns
+     */
+    public processAggregatedTimelineEvents(room?: Room, events?: MatrixEvent[]): void {
         if (!events?.length) return;
         if (!room) return;
 
         room.currentState.processBeaconEvents(events, this);
+        room.processPollEvents(events);
     }
 
     /**

src/common-crypto/CryptoBackend.ts

@@ -16,7 +16,10 @@ limitations under the License.
 
 import type { IEventDecryptionResult, IMegolmSessionData } from "../@types/crypto";
 import type { IToDeviceEvent } from "../sync-accumulator";
+import type { DeviceTrustLevel, UserTrustLevel } from "../crypto/CrossSigning";
 import { MatrixEvent } from "../models/event";
+import { Room } from "../models/room";
+import { IEncryptedEventInfo } from "../crypto/api";
 
 /**
  * Common interface for the crypto implementations
@@ -54,6 +57,45 @@ export interface CryptoBackend extends SyncCryptoCallbacks {
      */
     userHasCrossSigningKeys(): Promise<boolean>;
 
+    /**
+     * Get the verification level for a given user
+     *
+     * TODO: define this better
+     *
+     * @param userId - user to be checked
+     */
+    checkUserTrust(userId: string): UserTrustLevel;
+
+    /**
+     * Get the verification level for a given device
+     *
+     * TODO: define this better
+     *
+     * @param userId - user to be checked
+     * @param deviceId - device to be checked
+     */
+    checkDeviceTrust(userId: string, deviceId: string): DeviceTrustLevel;
+
+    /**
+     * Perform any background tasks that can be done before a message is ready to
+     * send, in order to speed up sending of the message.
+     *
+     * @param room - the room the event is in
+     */
+    prepareToEncrypt(room: Room): void;
+
+    /**
+     * Encrypt an event according to the configuration of the room.
+     *
+     * @param event -  event to be sent
+     *
+     * @param room - destination room.
+     *
+     * @returns Promise which resolves when the event has been
+     *     encrypted, or null if nothing was needed
+     */
+    encryptEvent(event: MatrixEvent, room: Room): Promise<void>;
+
     /**
      * Decrypt a received event
      *
@@ -62,6 +104,13 @@ export interface CryptoBackend extends SyncCryptoCallbacks {
      */
     decryptEvent(event: MatrixEvent): Promise<IEventDecryptionResult>;
 
+    /**
+     * Get information about the encryption of an event
+     *
+     * @param event - event to be checked
+     */
+    getEventEncryptionInfo(event: MatrixEvent): IEncryptedEventInfo;
+
     /**
      * Get a list containing all of the room keys
      *
@@ -89,6 +138,20 @@ export interface SyncCryptoCallbacks {
      */
     preprocessToDeviceMessages(events: IToDeviceEvent[]): Promise<IToDeviceEvent[]>;
 
+    /**
+     * Called by the /sync loop whenever an m.room.encryption event is received.
+     *
+     * This is called before RoomStateEvents are emitted for any of the events in the /sync
+     * response (even if the other events technically happened first). This works around a problem
+     * if the client uses a RoomStateEvent (typically a membership event) as a trigger to send a message
+     * in a new room (or one where encryption has been newly enabled): that would otherwise leave the
+     * crypto layer confused because it expects crypto to be set up, but it has not yet been.
+     *
+     * @param room - in which the event was received
+     * @param event - encryption event to be processed
+     */
+    onCryptoEvent(room: Room, event: MatrixEvent): Promise<void>;
+
     /**
      * Called by the /sync loop after each /sync response is processed.
      *

src/content-helpers.ts

@@ -14,11 +14,10 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { isProvided, REFERENCE_RELATION } from "matrix-events-sdk";
-
 import { MBeaconEventContent, MBeaconInfoContent, MBeaconInfoEventContent } from "./@types/beacon";
 import { MsgType } from "./@types/event";
-import { TEXT_NODE_TYPE } from "./@types/extensible_events";
+import { M_TEXT, REFERENCE_RELATION } from "./@types/extensible_events";
+import { isProvided } from "./extensible_events_v1/utilities";
 import {
     M_ASSET,
     LocationAssetType,
@@ -160,7 +159,7 @@ export const makeLocationContent = (
         [M_ASSET.name]: {
             type: assetType || LocationAssetType.Self,
         },
-        [TEXT_NODE_TYPE.name]: defaultedText,
+        [M_TEXT.name]: defaultedText,
         ...timestampEvent,
     } as LegacyLocationEventContent & MLocationEventContent;
 };
@@ -173,7 +172,7 @@ export const parseLocationEvent = (wireEventContent: LocationEventWireContent):
     const location = M_LOCATION.findIn<MLocationContent>(wireEventContent);
     const asset = M_ASSET.findIn<MAssetContent>(wireEventContent);
     const timestamp = M_TIMESTAMP.findIn<number>(wireEventContent);
-    const text = TEXT_NODE_TYPE.findIn<string>(wireEventContent);
+    const text = M_TEXT.findIn<string>(wireEventContent);
 
     const geoUri = location?.uri ?? wireEventContent?.geo_uri;
     const description = location?.description;

src/crypto/OlmDevice.ts

@@ -368,6 +368,11 @@ export class OlmDevice {
      */
     private saveSession(deviceKey: string, sessionInfo: IUnpickledSessionInfo, txn: unknown): void {
         const sessionId = sessionInfo.session.session_id();
+        logger.debug(`Saving Olm session ${sessionId} with device ${deviceKey}: ${sessionInfo.session.describe()}`);
+
+        // Why do we re-use the input object for this, overwriting the same key with a different
+        // type? Is it because we want to erase the unpickled session to enforce that it's no longer
+        // used? A comment would be great.
         const pickledSessionInfo = Object.assign(sessionInfo, {
             session: sessionInfo.session.pickle(this.pickleKey),
         });

src/crypto/algorithms/megolm.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2015 - 2021 The Matrix.org Foundation C.I.C.
+Copyright 2015 - 2021, 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -21,7 +21,7 @@ limitations under the License.
 import { v4 as uuidv4 } from "uuid";
 
 import type { IEventDecryptionResult, IMegolmSessionData } from "../../@types/crypto";
-import { logger } from "../../logger";
+import { logger, PrefixedLogger } from "../../logger";
 import * as olmlib from "../olmlib";
 import {
     DecryptionAlgorithm,
@@ -43,6 +43,7 @@ import { IMegolmEncryptedContent, IncomingRoomKeyRequest, IEncryptedContent } fr
 import { RoomKeyRequestState } from "../OutgoingRoomKeyRequestManager";
 import { OlmGroupSessionExtraData } from "../../@types/crypto";
 import { MatrixError } from "../../http-api";
+import { immediate } from "../../utils";
 
 // determine whether the key can be shared with invitees
 export function isRoomSharedHistory(room: Room): boolean {
@@ -73,7 +74,6 @@ export interface IOlmDevice<T = DeviceInfo> {
     deviceInfo: T;
 }
 
-/* eslint-disable camelcase */
 export interface IOutboundGroupSessionKey {
     chain_index: number;
     key: string;
@@ -106,7 +106,6 @@ interface IPayload extends Partial<IMessage> {
     algorithm?: string;
     sender_key?: string;
 }
-/* eslint-enable camelcase */
 
 interface SharedWithData {
     // The identity key of the device we shared with
@@ -223,13 +222,16 @@ export class MegolmEncryption extends EncryptionAlgorithm {
     private encryptionPreparation?: {
         promise: Promise<void>;
         startTime: number;
+        cancel: () => void;
     };
 
     protected readonly roomId: string;
+    private readonly prefixedLogger: PrefixedLogger;
 
     public constructor(params: IParams & Required<Pick<IParams, "roomId">>) {
         super(params);
         this.roomId = params.roomId;
+        this.prefixedLogger = logger.withPrefix(`[${this.roomId} encryption]`);
 
         this.sessionRotationPeriodMsgs = params.config?.rotation_period_msgs ?? 100;
         this.sessionRotationPeriodMs = params.config?.rotation_period_ms ?? 7 * 24 * 3600 * 1000;
@@ -291,7 +293,7 @@ export class MegolmEncryption extends EncryptionAlgorithm {
         // setupPromise resolves to `null` or the `OutboundSessionInfo` whether
         // or not the share succeeds
         this.setupPromise = fallible.catch((e) => {
-            logger.error(`Failed to setup outbound session in ${this.roomId}`, e);
+            this.prefixedLogger.error(`Failed to setup outbound session`, e);
             return null;
         });
 
@@ -311,7 +313,7 @@ export class MegolmEncryption extends EncryptionAlgorithm {
 
         // need to make a brand new session?
         if (session?.needsRotation(this.sessionRotationPeriodMsgs, this.sessionRotationPeriodMs)) {
-            logger.log("Starting new megolm session because we need to rotate.");
+            this.prefixedLogger.log("Starting new megolm session because we need to rotate.");
             session = null;
         }
 
@@ -321,9 +323,9 @@ export class MegolmEncryption extends EncryptionAlgorithm {
         }
 
         if (!session) {
-            logger.log(`Starting new megolm session for room ${this.roomId}`);
+            this.prefixedLogger.log("Starting new megolm session");
             session = await this.prepareNewSession(sharedHistory);
-            logger.log(`Started new megolm session ${session.sessionId} ` + `for room ${this.roomId}`);
+            this.prefixedLogger.log(`Started new megolm session ${session.sessionId}`);
             this.outboundSessions[session.sessionId] = session;
         }
 
@@ -376,14 +378,24 @@ export class MegolmEncryption extends EncryptionAlgorithm {
         await Promise.all([
             (async (): Promise<void> => {
                 // share keys with devices that we already have a session for
-                logger.debug(`Sharing keys with existing Olm sessions in ${this.roomId}`, olmSessions);
+                const olmSessionList = Object.entries(olmSessions)
+                    .map(([userId, sessionsByUser]) =>
+                        Object.entries(sessionsByUser).map(
+                            ([deviceId, session]) => `${userId}/${deviceId}: ${session.sessionId}`,
+                        ),
+                    )
+                    .flat(1);
+                this.prefixedLogger.debug("Sharing keys with devices with existing Olm sessions:", olmSessionList);
                 await this.shareKeyWithOlmSessions(session, key, payload, olmSessions);
-                logger.debug(`Shared keys with existing Olm sessions in ${this.roomId}`);
+                this.prefixedLogger.debug("Shared keys with existing Olm sessions");
             })(),
             (async (): Promise<void> => {
-                logger.debug(
-                    `Sharing keys (start phase 1) with new Olm sessions in ${this.roomId}`,
-                    devicesWithoutSession,
+                const deviceList = Object.entries(devicesWithoutSession)
+                    .map(([userId, devicesByUser]) => devicesByUser.map((device) => `${userId}/${device.deviceId}`))
+                    .flat(1);
+                this.prefixedLogger.debug(
+                    "Sharing keys (start phase 1) with devices without existing Olm sessions:",
+                    deviceList,
                 );
                 const errorDevices: IOlmDevice[] = [];
 
@@ -403,7 +415,7 @@ export class MegolmEncryption extends EncryptionAlgorithm {
                     singleOlmCreationPhase ? 10000 : 2000,
                     failedServers,
                 );
-                logger.debug(`Shared keys (end phase 1) with new Olm sessions in ${this.roomId}`);
+                this.prefixedLogger.debug("Shared keys (end phase 1) with devices without existing Olm sessions");
 
                 if (!singleOlmCreationPhase && Date.now() - start < 10000) {
                     // perform the second phase of olm session creation if requested,
@@ -432,25 +444,40 @@ export class MegolmEncryption extends EncryptionAlgorithm {
                             }
                         }
 
-                        logger.debug(`Sharing keys (start phase 2) with new Olm sessions in ${this.roomId}`);
-                        await this.shareKeyWithDevices(session, key, payload, retryDevices, failedDevices, 30000);
-                        logger.debug(`Shared keys (end phase 2) with new Olm sessions in ${this.roomId}`);
+                        const retryDeviceList = Object.entries(retryDevices)
+                            .map(([userId, devicesByUser]) =>
+                                devicesByUser.map((device) => `${userId}/${device.deviceId}`),
+                            )
+                            .flat(1);
+
+                        if (retryDeviceList.length > 0) {
+                            this.prefixedLogger.debug(
+                                "Sharing keys (start phase 2) with devices without existing Olm sessions:",
+                                retryDeviceList,
+                            );
+                            await this.shareKeyWithDevices(session, key, payload, retryDevices, failedDevices, 30000);
+                            this.prefixedLogger.debug(
+                                "Shared keys (end phase 2) with devices without existing Olm sessions",
+                            );
+                        }
 
                         await this.notifyFailedOlmDevices(session, key, failedDevices);
                     })();
                 } else {
                     await this.notifyFailedOlmDevices(session, key, errorDevices);
                 }
-                logger.debug(`Shared keys (all phases done) with new Olm sessions in ${this.roomId}`);
             })(),
             (async (): Promise<void> => {
-                logger.debug(
-                    `There are ${Object.entries(blocked).length} blocked devices in ${this.roomId}`,
-                    Object.entries(blocked),
+                this.prefixedLogger.debug(
+                    `There are ${Object.entries(blocked).length} blocked devices:`,
+                    Object.entries(blocked)
+                        .map(([userId, blockedByUser]) =>
+                            Object.entries(blockedByUser).map(([deviceId, _deviceInfo]) => `${userId}/${deviceId}`),
+                        )
+                        .flat(1),
                 );
 
                 // also, notify newly blocked devices that they're blocked
-                logger.debug(`Notifying newly blocked devices in ${this.roomId}`);
                 const blockedMap: Record<string, Record<string, { device: IBlockedDevice }>> = {};
                 let blockedCount = 0;
                 for (const [userId, userBlockedDevices] of Object.entries(blocked)) {
@@ -466,8 +493,18 @@ export class MegolmEncryption extends EncryptionAlgorithm {
                     }
                 }
 
-                await this.notifyBlockedDevices(session, blockedMap);
-                logger.debug(`Notified ${blockedCount} newly blocked devices in ${this.roomId}`, blockedMap);
+                if (blockedCount) {
+                    this.prefixedLogger.debug(
+                        `Notifying ${blockedCount} newly blocked devices:`,
+                        Object.entries(blockedMap)
+                            .map(([userId, blockedByUser]) =>
+                                Object.entries(blockedByUser).map(([deviceId, _deviceInfo]) => `${userId}/${deviceId}`),
+                            )
+                            .flat(1),
+                    );
+                    await this.notifyBlockedDevices(session, blockedMap);
+                    this.prefixedLogger.debug(`Notified ${blockedCount} newly blocked devices`);
+                }
             })(),
         ]);
     }
@@ -620,7 +657,7 @@ export class MegolmEncryption extends EncryptionAlgorithm {
                 }
             })
             .catch((error) => {
-                logger.error("failed to encryptAndSendToDevices", error);
+                this.prefixedLogger.error("failed to encryptAndSendToDevices", error);
                 throw error;
             });
     }
@@ -694,25 +731,25 @@ export class MegolmEncryption extends EncryptionAlgorithm {
     ): Promise<void> {
         const obSessionInfo = this.outboundSessions[sessionId];
         if (!obSessionInfo) {
-            logger.debug(`megolm session ${senderKey}|${sessionId} not found: not re-sharing keys`);
+            this.prefixedLogger.debug(`megolm session ${senderKey}|${sessionId} not found: not re-sharing keys`);
             return;
         }
 
         // The chain index of the key we previously sent this device
         if (obSessionInfo.sharedWithDevices[userId] === undefined) {
-            logger.debug(`megolm session ${senderKey}|${sessionId} never shared with user ${userId}`);
+            this.prefixedLogger.debug(`megolm session ${senderKey}|${sessionId} never shared with user ${userId}`);
             return;
         }
         const sessionSharedData = obSessionInfo.sharedWithDevices[userId][device.deviceId];
         if (sessionSharedData === undefined) {
-            logger.debug(
+            this.prefixedLogger.debug(
                 `megolm session ${senderKey}|${sessionId} never shared with device ${userId}:${device.deviceId}`,
             );
             return;
         }
 
         if (sessionSharedData.deviceKey !== device.getIdentityKey()) {
-            logger.warn(
+            this.prefixedLogger.warn(
                 `Megolm session ${senderKey}|${sessionId} has been shared with device ${device.deviceId} but ` +
                     `with identity key ${sessionSharedData.deviceKey}. Key is now ${device.getIdentityKey()}!`,
             );
@@ -729,7 +766,7 @@ export class MegolmEncryption extends EncryptionAlgorithm {
         );
 
         if (!key) {
-            logger.warn(
+            this.prefixedLogger.warn(
                 `No inbound session key found for megolm session ${senderKey}|${sessionId}: not re-sharing keys`,
             );
             return;
@@ -775,7 +812,9 @@ export class MegolmEncryption extends EncryptionAlgorithm {
                 [device.deviceId]: encryptedContent,
             },
         });
-        logger.debug(`Re-shared key for megolm session ${senderKey}|${sessionId} with ${userId}:${device.deviceId}`);
+        this.prefixedLogger.debug(
+            `Re-shared key for megolm session ${senderKey}|${sessionId} with ${userId}:${device.deviceId}`,
+        );
     }
 
     /**
@@ -807,7 +846,6 @@ export class MegolmEncryption extends EncryptionAlgorithm {
         otkTimeout: number,
         failedServers?: string[],
     ): Promise<void> {
-        logger.debug(`Ensuring Olm sessions for devices in ${this.roomId}`);
         const devicemap = await olmlib.ensureOlmSessionsForDevices(
             this.olmDevice,
             this.baseApis,
@@ -815,15 +853,10 @@ export class MegolmEncryption extends EncryptionAlgorithm {
             false,
             otkTimeout,
             failedServers,
-            logger.withPrefix?.(`[${this.roomId}]`),
+            this.prefixedLogger,
         );
-        logger.debug(`Ensured Olm sessions for devices in ${this.roomId}`);
-
         this.getDevicesWithoutSessions(devicemap, devicesByUser, errorDevices);
-
-        logger.debug(`Sharing keys with newly created Olm sessions in ${this.roomId}`);
         await this.shareKeyWithOlmSessions(session, key, payload, devicemap);
-        logger.debug(`Shared keys with newly created Olm sessions in ${this.roomId}`);
     }
 
     private async shareKeyWithOlmSessions(
@@ -835,17 +868,16 @@ export class MegolmEncryption extends EncryptionAlgorithm {
         const userDeviceMaps = this.splitDevices(devicemap);
 
         for (let i = 0; i < userDeviceMaps.length; i++) {
-            const taskDetail =
-                `megolm keys for ${session.sessionId} ` + `in ${this.roomId} (slice ${i + 1}/${userDeviceMaps.length})`;
+            const taskDetail = `megolm keys for ${session.sessionId} (slice ${i + 1}/${userDeviceMaps.length})`;
             try {
-                logger.debug(
+                this.prefixedLogger.debug(
                     `Sharing ${taskDetail}`,
                     userDeviceMaps[i].map((d) => `${d.userId}/${d.deviceInfo.deviceId}`),
                 );
                 await this.encryptAndSendKeysToDevices(session, key.chain_index, userDeviceMaps[i], payload);
-                logger.debug(`Shared ${taskDetail}`);
+                this.prefixedLogger.debug(`Shared ${taskDetail}`);
             } catch (e) {
-                logger.error(`Failed to share ${taskDetail}`);
+                this.prefixedLogger.error(`Failed to share ${taskDetail}`);
                 throw e;
             }
         }
@@ -864,9 +896,7 @@ export class MegolmEncryption extends EncryptionAlgorithm {
         key: IOutboundGroupSessionKey,
         failedDevices: IOlmDevice[],
     ): Promise<void> {
-        logger.debug(
-            `Notifying ${failedDevices.length} devices we failed to ` + `create Olm sessions in ${this.roomId}`,
-        );
+        this.prefixedLogger.debug(`Notifying ${failedDevices.length} devices we failed to create Olm sessions`);
 
         // mark the devices that failed as "handled" because we don't want to try
         // to claim a one-time-key for dead devices on every message.
@@ -877,9 +907,8 @@ export class MegolmEncryption extends EncryptionAlgorithm {
         }
 
         const unnotifiedFailedDevices = await this.olmDevice.filterOutNotifiedErrorDevices(failedDevices);
-        logger.debug(
-            `Need to notify ${unnotifiedFailedDevices.length} failed devices ` +
-                `which haven't been notified before in ${this.roomId}`,
+        this.prefixedLogger.debug(
+            `Need to notify ${unnotifiedFailedDevices.length} failed devices which haven't been notified before`,
         );
         const blockedMap: Record<string, Record<string, { device: IBlockedDevice }>> = {};
         for (const { userId, deviceInfo } of unnotifiedFailedDevices) {
@@ -898,9 +927,8 @@ export class MegolmEncryption extends EncryptionAlgorithm {
 
         // send the notifications
         await this.notifyBlockedDevices(session, blockedMap);
-        logger.debug(
-            `Notified ${unnotifiedFailedDevices.length} devices we failed to ` +
-                `create Olm sessions in ${this.roomId}`,
+        this.prefixedLogger.debug(
+            `Notified ${unnotifiedFailedDevices.length} devices we failed to create Olm sessions`,
         );
     }
 
@@ -926,14 +954,14 @@ export class MegolmEncryption extends EncryptionAlgorithm {
         for (let i = 0; i < userDeviceMaps.length; i++) {
             try {
                 await this.sendBlockedNotificationsToDevices(session, userDeviceMaps[i], payload);
-                logger.log(
+                this.prefixedLogger.log(
                     `Completed blacklist notification for ${session.sessionId} ` +
-                        `in ${this.roomId} (slice ${i + 1}/${userDeviceMaps.length})`,
+                        `(slice ${i + 1}/${userDeviceMaps.length})`,
                 );
             } catch (e) {
-                logger.log(
-                    `blacklist notification for ${session.sessionId} in ` +
-                        `${this.roomId} (slice ${i + 1}/${userDeviceMaps.length}) failed`,
+                this.prefixedLogger.log(
+                    `blacklist notification for ${session.sessionId} ` +
+                        `(slice ${i + 1}/${userDeviceMaps.length}) failed`,
                 );
 
                 throw e;
@@ -946,27 +974,36 @@ export class MegolmEncryption extends EncryptionAlgorithm {
      * send, in order to speed up sending of the message.
      *
      * @param room - the room the event is in
+     * @returns A function that, when called, will stop the preparation
      */
-    public prepareToEncrypt(room: Room): void {
-        if (this.encryptionPreparation != null) {
-            // We're already preparing something, so don't do anything else.
-            // FIXME: check if we need to restart
-            // (https://github.com/matrix-org/matrix-js-sdk/issues/1255)
-            const elapsedTime = Date.now() - this.encryptionPreparation.startTime;
-            logger.debug(
-                `Already started preparing to encrypt for ${this.roomId} ` + `${elapsedTime} ms ago, skipping`,
-            );
-            return;
+    public prepareToEncrypt(room: Room): () => void {
+        if (room.roomId !== this.roomId) {
+            throw new Error("MegolmEncryption.prepareToEncrypt called on unexpected room");
         }
 
-        logger.debug(`Preparing to encrypt events for ${this.roomId}`);
+        if (this.encryptionPreparation != null) {
+            // We're already preparing something, so don't do anything else.
+            const elapsedTime = Date.now() - this.encryptionPreparation.startTime;
+            this.prefixedLogger.debug(
+                `Already started preparing to encrypt for this room ${elapsedTime}ms ago, skipping`,
+            );
+            return this.encryptionPreparation.cancel;
+        }
+
+        this.prefixedLogger.debug("Preparing to encrypt events");
+
+        let cancelled = false;
+        const isCancelled = (): boolean => cancelled;
 
         this.encryptionPreparation = {
             startTime: Date.now(),
             promise: (async (): Promise<void> => {
                 try {
-                    logger.debug(`Getting devices in ${this.roomId}`);
-                    const [devicesInRoom, blocked] = await this.getDevicesInRoom(room);
+                    // Attempt to enumerate the devices in room, and gracefully
+                    // handle cancellation if it occurs.
+                    const getDevicesResult = await this.getDevicesInRoom(room, false, isCancelled);
+                    if (getDevicesResult === null) return;
+                    const [devicesInRoom, blocked] = getDevicesResult;
 
                     if (this.crypto.globalErrorOnUnknownDevices) {
                         // Drop unknown devices for now.  When the message gets sent, we'll
@@ -975,17 +1012,26 @@ export class MegolmEncryption extends EncryptionAlgorithm {
                         this.removeUnknownDevices(devicesInRoom);
                     }
 
-                    logger.debug(`Ensuring outbound session in ${this.roomId}`);
+                    this.prefixedLogger.debug("Ensuring outbound megolm session");
                     await this.ensureOutboundSession(room, devicesInRoom, blocked, true);
 
-                    logger.debug(`Ready to encrypt events for ${this.roomId}`);
+                    this.prefixedLogger.debug("Ready to encrypt events");
                 } catch (e) {
-                    logger.error(`Failed to prepare to encrypt events for ${this.roomId}`, e);
+                    this.prefixedLogger.error("Failed to prepare to encrypt events", e);
                 } finally {
                     delete this.encryptionPreparation;
                 }
             })(),
+
+            cancel: (): void => {
+                // The caller has indicated that the process should be cancelled,
+                // so tell the promise that we'd like to halt, and reset the preparation state.
+                cancelled = true;
+                delete this.encryptionPreparation;
+            },
         };
+
+        return this.encryptionPreparation.cancel;
     }
 
     /**
@@ -994,7 +1040,7 @@ export class MegolmEncryption extends EncryptionAlgorithm {
      * @returns Promise which resolves to the new event body
      */
     public async encryptMessage(room: Room, eventType: string, content: IContent): Promise<IMegolmEncryptedContent> {
-        logger.log(`Starting to encrypt event for ${this.roomId}`);
+        this.prefixedLogger.log("Starting to encrypt event");
 
         if (this.encryptionPreparation != null) {
             // If we started sending keys, wait for it to be done.
@@ -1134,18 +1180,38 @@ export class MegolmEncryption extends EncryptionAlgorithm {
      *
      * @param forceDistributeToUnverified - if set to true will include the unverified devices
      * even if setting is set to block them (useful for verification)
+     * @param isCancelled - will cause the procedure to abort early if and when it starts
+     * returning `true`. If omitted, cancellation won't happen.
      *
-     * @returns Promise which resolves to an array whose
-     *     first element is a map from userId to deviceId to deviceInfo indicating
+     * @returns Promise which resolves to `null`, or an array whose
+     *     first element is a {@link DeviceInfoMap} indicating
      *     the devices that messages should be encrypted to, and whose second
      *     element is a map from userId to deviceId to data indicating the devices
-     *     that are in the room but that have been blocked
+     *     that are in the room but that have been blocked.
+     *     If `isCancelled` is provided and returns `true` while processing, `null`
+     *     will be returned.
+     *     If `isCancelled` is not provided, the Promise will never resolve to `null`.
      */
+    private async getDevicesInRoom(
+        room: Room,
+        forceDistributeToUnverified?: boolean,
+    ): Promise<[DeviceInfoMap, IBlockedMap]>;
+    private async getDevicesInRoom(
+        room: Room,
+        forceDistributeToUnverified?: boolean,
+        isCancelled?: () => boolean,
+    ): Promise<null | [DeviceInfoMap, IBlockedMap]>;
     private async getDevicesInRoom(
         room: Room,
         forceDistributeToUnverified = false,
-    ): Promise<[DeviceInfoMap, IBlockedMap]> {
+        isCancelled?: () => boolean,
+    ): Promise<null | [DeviceInfoMap, IBlockedMap]> {
         const members = await room.getEncryptionTargetMembers();
+        this.prefixedLogger.debug(
+            `Encrypting for users (shouldEncryptForInvitedMembers: ${room.shouldEncryptForInvitedMembers()}):`,
+            members.map((u) => `${u.userId} (${u.membership})`),
+        );
+
         const roomMembers = members.map(function (u) {
             return u.userId;
         });
@@ -1165,6 +1231,11 @@ export class MegolmEncryption extends EncryptionAlgorithm {
         // See https://github.com/vector-im/element-web/issues/2305 for details.
         const devices = await this.crypto.downloadKeys(roomMembers, false);
         const blocked: IBlockedMap = {};
+
+        if (isCancelled?.() === true) {
+            return null;
+        }
+
         // remove any blocked devices
         for (const userId in devices) {
             if (!devices.hasOwnProperty(userId)) {
@@ -1177,6 +1248,11 @@ export class MegolmEncryption extends EncryptionAlgorithm {
                     continue;
                 }
 
+                // Yield prior to checking each device so that we don't block
+                // updating/rendering for too long.
+                // See https://github.com/vector-im/element-web/issues/21612
+                if (isCancelled !== undefined) await immediate();
+                if (isCancelled?.() === true) return null;
                 const deviceTrust = this.crypto.checkDeviceTrust(userId, deviceId);
 
                 if (
@@ -1216,10 +1292,12 @@ export class MegolmDecryption extends DecryptionAlgorithm {
     private olmlib = olmlib;
 
     protected readonly roomId: string;
+    private readonly prefixedLogger: PrefixedLogger;
 
     public constructor(params: DecryptionClassParams<IParams & Required<Pick<IParams, "roomId">>>) {
         super(params);
         this.roomId = params.roomId;
+        this.prefixedLogger = logger.withPrefix(`[${this.roomId} decryption]`);
     }
 
     /**
@@ -1266,7 +1344,7 @@ export class MegolmDecryption extends DecryptionAlgorithm {
                 errorCode = "OLM_UNKNOWN_MESSAGE_INDEX";
             }
 
-            throw new DecryptionError(errorCode, e ? e.toString() : "Unknown Error: Error is undefined", {
+            throw new DecryptionError(errorCode, e instanceof Error ? e.message : "Unknown Error: Error is undefined", {
                 session: content.sender_key + "|" + content.session_id,
             });
         }
@@ -1287,9 +1365,10 @@ export class MegolmDecryption extends DecryptionAlgorithm {
             // event was sent.  Use a fuzz factor of 2 minutes.
             const problem = await this.olmDevice.sessionMayHaveProblems(content.sender_key, event.getTs() - 120000);
             if (problem) {
-                logger.info(
+                this.prefixedLogger.info(
                     `When handling UISI from ${event.getSender()} (sender key ${content.sender_key}): ` +
-                        `recent session problem with that sender: ${problem}`,
+                        `recent session problem with that sender:`,
+                    problem,
                 );
                 let problemDescription = PROBLEM_DESCRIPTIONS[problem.type as "no_olm"] || PROBLEM_DESCRIPTIONS.unknown;
                 if (problem.fixed) {
@@ -1406,12 +1485,12 @@ export class MegolmDecryption extends DecryptionAlgorithm {
         const extraSessionData: OlmGroupSessionExtraData = {};
 
         if (!content.room_id || !content.session_key || !content.session_id || !content.algorithm) {
-            logger.error("key event is missing fields");
+            this.prefixedLogger.error("key event is missing fields");
             return;
         }
 
         if (!olmlib.isOlmEncrypted(event)) {
-            logger.error("key event not properly encrypted");
+            this.prefixedLogger.error("key event not properly encrypted");
             return;
         }
 
@@ -1426,7 +1505,7 @@ export class MegolmDecryption extends DecryptionAlgorithm {
                 senderKey,
             );
             if (senderKeyUser !== event.getSender()) {
-                logger.error("sending device does not belong to the user it claims to be from");
+                this.prefixedLogger.error("sending device does not belong to the user it claims to be from");
                 return;
             }
             const outgoingRequests = deviceInfo
@@ -1453,7 +1532,7 @@ export class MegolmDecryption extends DecryptionAlgorithm {
                 // not one of our other devices and it's not shared
                 // history, ignore it
                 if (!extraSessionData.sharedHistory) {
-                    logger.log("forwarded key not shared history - ignoring");
+                    this.prefixedLogger.log("forwarded key not shared history - ignoring");
                     return;
                 }
 
@@ -1461,7 +1540,7 @@ export class MegolmDecryption extends DecryptionAlgorithm {
                 // we're already in, and they're not one of our other
                 // devices or the one who invited us, ignore it
                 if (room && !fromInviter) {
-                    logger.log("forwarded key not from inviter or from us - ignoring");
+                    this.prefixedLogger.log("forwarded key not from inviter or from us - ignoring");
                     return;
                 }
             }
@@ -1476,13 +1555,13 @@ export class MegolmDecryption extends DecryptionAlgorithm {
             forwardingKeyChain.push(senderKey);
 
             if (!content.sender_key) {
-                logger.error("forwarded_room_key event is missing sender_key field");
+                this.prefixedLogger.error("forwarded_room_key event is missing sender_key field");
                 return;
             }
 
             const ed25519Key = content.sender_claimed_ed25519_key;
             if (!ed25519Key) {
-                logger.error(`forwarded_room_key_event is missing sender_claimed_ed25519_key field`);
+                this.prefixedLogger.error(`forwarded_room_key_event is missing sender_claimed_ed25519_key field`);
                 return;
             }
 
@@ -1506,7 +1585,7 @@ export class MegolmDecryption extends DecryptionAlgorithm {
                     "readwrite",
                     ["parked_shared_history"],
                     (txn) => this.crypto.cryptoStore.addParkedSharedHistory(content.room_id!, parkedData, txn),
-                    logger.withPrefix("[addParkedSharedHistory]"),
+                    this.prefixedLogger.withPrefix("[addParkedSharedHistory]"),
                 );
                 return;
             }
@@ -1563,7 +1642,7 @@ export class MegolmDecryption extends DecryptionAlgorithm {
             // don't wait for the keys to be backed up for the server
             await this.crypto.backupManager.backupGroupSession(senderKey, content.session_id);
         } catch (e) {
-            logger.error(`Error handling m.room_key_event: ${e}`);
+            this.prefixedLogger.error(`Error handling m.room_key_event: ${e}`);
         }
     }
 
@@ -1575,65 +1654,10 @@ export class MegolmDecryption extends DecryptionAlgorithm {
         const senderKey = content.sender_key;
 
         if (content.code === "m.no_olm") {
-            const sender = event.getSender()!;
-            logger.warn(`${sender}:${senderKey} was unable to establish an olm session with us`);
-            // if the sender says that they haven't been able to establish an olm
-            // session, let's proactively establish one
-
-            // Note: after we record that the olm session has had a problem, we
-            // trigger retrying decryption for all the messages from the sender's
-            // key, so that we can update the error message to indicate the olm
-            // session problem.
-
-            if (await this.olmDevice.getSessionIdForDevice(senderKey)) {
-                // a session has already been established, so we don't need to
-                // create a new one.
-                logger.debug("New session already created.  Not creating a new one.");
-                await this.olmDevice.recordSessionProblem(senderKey, "no_olm", true);
-                this.retryDecryptionFromSender(senderKey);
-                return;
-            }
-            let device = this.crypto.deviceList.getDeviceByIdentityKey(content.algorithm, senderKey);
-            if (!device) {
-                // if we don't know about the device, fetch the user's devices again
-                // and retry before giving up
-                await this.crypto.downloadKeys([sender], false);
-                device = this.crypto.deviceList.getDeviceByIdentityKey(content.algorithm, senderKey);
-                if (!device) {
-                    logger.info("Couldn't find device for identity key " + senderKey + ": not establishing session");
-                    await this.olmDevice.recordSessionProblem(senderKey, "no_olm", false);
-                    this.retryDecryptionFromSender(senderKey);
-                    return;
-                }
-            }
-
-            // XXX: switch this to use encryptAndSendToDevices() rather than duplicating it?
-
-            await olmlib.ensureOlmSessionsForDevices(this.olmDevice, this.baseApis, { [sender]: [device] }, false);
-            const encryptedContent: IEncryptedContent = {
-                algorithm: olmlib.OLM_ALGORITHM,
-                sender_key: this.olmDevice.deviceCurve25519Key!,
-                ciphertext: {},
-                [ToDeviceMessageId]: uuidv4(),
-            };
-            await olmlib.encryptMessageForDevice(
-                encryptedContent.ciphertext,
-                this.userId,
-                undefined,
-                this.olmDevice,
-                sender,
-                device,
-                { type: "m.dummy" },
-            );
-
-            await this.olmDevice.recordSessionProblem(senderKey, "no_olm", true);
-            this.retryDecryptionFromSender(senderKey);
-
-            await this.baseApis.sendToDevice("m.room.encrypted", {
-                [sender]: {
-                    [device.deviceId]: encryptedContent,
-                },
-            });
+            await this.onNoOlmWithheldEvent(event);
+        } else if (content.code === "m.unavailable") {
+            // this simply means that the other device didn't have the key, which isn't very useful information. Don't
+            // record it in the storage
         } else {
             await this.olmDevice.addInboundGroupSessionWithheld(
                 content.room_id,
@@ -1643,6 +1667,78 @@ export class MegolmDecryption extends DecryptionAlgorithm {
                 content.reason,
             );
         }
+
+        // Having recorded the problem, retry decryption on any affected messages.
+        // It's unlikely we'll be able to decrypt sucessfully now, but this will
+        // update the error message.
+        //
+        if (content.session_id) {
+            await this.retryDecryption(senderKey, content.session_id);
+        } else {
+            // no_olm messages aren't specific to a given megolm session, so
+            // we trigger retrying decryption for all the messages from the sender's
+            // key, so that we can update the error message to indicate the olm
+            // session problem.
+            await this.retryDecryptionFromSender(senderKey);
+        }
+    }
+
+    private async onNoOlmWithheldEvent(event: MatrixEvent): Promise<void> {
+        const content = event.getContent();
+        const senderKey = content.sender_key;
+        const sender = event.getSender()!;
+        this.prefixedLogger.warn(`${sender}:${senderKey} was unable to establish an olm session with us`);
+        // if the sender says that they haven't been able to establish an olm
+        // session, let's proactively establish one
+
+        if (await this.olmDevice.getSessionIdForDevice(senderKey)) {
+            // a session has already been established, so we don't need to
+            // create a new one.
+            this.prefixedLogger.debug("New session already created.  Not creating a new one.");
+            await this.olmDevice.recordSessionProblem(senderKey, "no_olm", true);
+            return;
+        }
+        let device = this.crypto.deviceList.getDeviceByIdentityKey(content.algorithm, senderKey);
+        if (!device) {
+            // if we don't know about the device, fetch the user's devices again
+            // and retry before giving up
+            await this.crypto.downloadKeys([sender], false);
+            device = this.crypto.deviceList.getDeviceByIdentityKey(content.algorithm, senderKey);
+            if (!device) {
+                this.prefixedLogger.info(
+                    "Couldn't find device for identity key " + senderKey + ": not establishing session",
+                );
+                await this.olmDevice.recordSessionProblem(senderKey, "no_olm", false);
+                return;
+            }
+        }
+
+        // XXX: switch this to use encryptAndSendToDevices() rather than duplicating it?
+
+        await olmlib.ensureOlmSessionsForDevices(this.olmDevice, this.baseApis, { [sender]: [device] }, false);
+        const encryptedContent: IEncryptedContent = {
+            algorithm: olmlib.OLM_ALGORITHM,
+            sender_key: this.olmDevice.deviceCurve25519Key!,
+            ciphertext: {},
+            [ToDeviceMessageId]: uuidv4(),
+        };
+        await olmlib.encryptMessageForDevice(
+            encryptedContent.ciphertext,
+            this.userId,
+            undefined,
+            this.olmDevice,
+            sender,
+            device,
+            { type: "m.dummy" },
+        );
+
+        await this.olmDevice.recordSessionProblem(senderKey, "no_olm", true);
+
+        await this.baseApis.sendToDevice("m.room.encrypted", {
+            [sender]: {
+                [device.deviceId]: encryptedContent,
+            },
+        });
     }
 
     public hasKeysForKeyRequest(keyRequest: IncomingRoomKeyRequest): Promise<boolean> {
@@ -1679,7 +1775,7 @@ export class MegolmDecryption extends DecryptionAlgorithm {
                     return null;
                 }
 
-                logger.log(
+                this.prefixedLogger.log(
                     "sharing keys for session " +
                         body.sender_key +
                         "|" +
@@ -1778,7 +1874,7 @@ export class MegolmDecryption extends DecryptionAlgorithm {
                     this.crypto.backupManager.backupGroupSession(session.sender_key, session.session_id).catch((e) => {
                         // This throws if the upload failed, but this is fine
                         // since it will have written it to the db and will retry.
-                        logger.log("Failed to back up megolm session", e);
+                        this.prefixedLogger.log("Failed to back up megolm session", e);
                     });
                 }
                 // have another go at decrypting events sent with this session.
@@ -1812,10 +1908,14 @@ export class MegolmDecryption extends DecryptionAlgorithm {
             return true;
         }
 
-        logger.debug("Retrying decryption on events", [...pending]);
+        const pendingList = [...pending];
+        this.prefixedLogger.debug(
+            "Retrying decryption on events:",
+            pendingList.map((e) => `${e.getId()}`),
+        );
 
         await Promise.all(
-            [...pending].map(async (ev) => {
+            pendingList.map(async (ev) => {
                 try {
                     await ev.attemptDecryption(this.crypto, { isRetry: true, forceRedecryptIfUntrusted });
                 } catch (e) {
@@ -1858,8 +1958,8 @@ export class MegolmDecryption extends DecryptionAlgorithm {
         await olmlib.ensureOlmSessionsForDevices(this.olmDevice, this.baseApis, devicesByUser);
 
         const sharedHistorySessions = await this.olmDevice.getSharedHistoryInboundGroupSessions(this.roomId);
-        logger.log(
-            `Sharing history in ${this.roomId} with users ${Object.keys(devicesByUser)}`,
+        this.prefixedLogger.log(
+            `Sharing history in with users ${Object.keys(devicesByUser)}`,
             sharedHistorySessions.map(([senderKey, sessionId]) => `${senderKey}|${sessionId}`),
         );
         for (const [senderKey, sessionId] of sharedHistorySessions) {
@@ -1900,20 +2000,20 @@ export class MegolmDecryption extends DecryptionAlgorithm {
             for (const userId of Object.keys(contentMap)) {
                 for (const deviceId of Object.keys(contentMap[userId])) {
                     if (Object.keys(contentMap[userId][deviceId].ciphertext).length === 0) {
-                        logger.log("No ciphertext for device " + userId + ":" + deviceId + ": pruning");
+                        this.prefixedLogger.log("No ciphertext for device " + userId + ":" + deviceId + ": pruning");
                         delete contentMap[userId][deviceId];
                     }
                 }
                 // No devices left for that user? Strip that too.
                 if (Object.keys(contentMap[userId]).length === 0) {
-                    logger.log("Pruned all devices for user " + userId);
+                    this.prefixedLogger.log("Pruned all devices for user " + userId);
                     delete contentMap[userId];
                 }
             }
 
             // Is there anything left?
             if (Object.keys(contentMap).length === 0) {
-                logger.log("No users left to send to: aborting");
+                this.prefixedLogger.log("No users left to send to: aborting");
                 return;
             }
 

src/crypto/index.ts

@@ -1202,6 +1202,7 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
      */
     public async storeSessionBackupPrivateKey(key: ArrayLike<number>): Promise<void> {
         if (!(key instanceof Uint8Array)) {
+            // eslint-disable-next-line @typescript-eslint/no-base-to-string
             throw new Error(`storeSessionBackupPrivateKey expects Uint8Array, got ${key}`);
         }
         const pickleKey = Buffer.from(this.olmDevice.pickleKey);
@@ -2808,11 +2809,7 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
      * @returns Promise which resolves when the event has been
      *     encrypted, or null if nothing was needed
      */
-    public async encryptEvent(event: MatrixEvent, room?: Room): Promise<void> {
-        if (!room) {
-            throw new Error("Cannot send encrypted messages in unknown rooms");
-        }
-
+    public async encryptEvent(event: MatrixEvent, room: Room): Promise<void> {
         const roomId = event.getRoomId()!;
 
         const alg = this.roomEncryptors.get(roomId);
@@ -3433,6 +3430,8 @@ export class Crypto extends TypedEventEmitter<CryptoEvent, CryptoEventHandlerMap
         const algorithm = content.algorithm;
         const deviceKey = content.sender_key;
 
+        this.baseApis.emit(ClientEvent.UndecryptableToDeviceEvent, event);
+
         // retry decryption for all events sent by the sender_key.  This will
         // update the events to show a message indicating that the olm session was
         // wedged.

src/crypto/verification/SAS.ts

@@ -159,6 +159,7 @@ function generateSas(sasBytes: Uint8Array, methods: string[]): IGeneratedSas {
 const macMethods = {
     "hkdf-hmac-sha256": "calculate_mac",
     "org.matrix.msc3783.hkdf-hmac-sha256": "calculate_mac_fixed_base64",
+    "hkdf-hmac-sha256.v2": "calculate_mac_fixed_base64",
     "hmac-sha256": "calculate_mac_long_kdf",
 } as const;
 
@@ -202,7 +203,12 @@ type KeyAgreement = keyof typeof calculateKeyAgreement;
  */
 const KEY_AGREEMENT_LIST: KeyAgreement[] = ["curve25519-hkdf-sha256", "curve25519"];
 const HASHES_LIST = ["sha256"];
-const MAC_LIST: MacMethod[] = ["org.matrix.msc3783.hkdf-hmac-sha256", "hkdf-hmac-sha256", "hmac-sha256"];
+const MAC_LIST: MacMethod[] = [
+    "hkdf-hmac-sha256.v2",
+    "org.matrix.msc3783.hkdf-hmac-sha256",
+    "hkdf-hmac-sha256",
+    "hmac-sha256",
+];
 const SAS_LIST = Object.keys(sasGenerators);
 
 const KEY_AGREEMENT_SET = new Set(KEY_AGREEMENT_LIST);

src/event-mapper.ts

@@ -16,6 +16,7 @@ limitations under the License.
 
 import { MatrixClient } from "./client";
 import { IEvent, MatrixEvent, MatrixEventEvent } from "./models/event";
+import { RelationType } from "./@types/event";
 
 export type EventMapper = (obj: Partial<IEvent>) => MatrixEvent;
 
@@ -55,6 +56,19 @@ export function eventMapperFor(client: MatrixClient, options: MapperOpts): Event
             preventReEmit = true;
         }
 
+        // if there is a complete edit bundled alongside the event, perform the replacement.
+        // (prior to MSC3925, events were automatically replaced on the server-side. MSC3925 proposes that that doesn't
+        // happen automatically but the server does provide us with the whole content of the edit event.)
+        const bundledEdit = event.getServerAggregatedRelation<Partial<IEvent>>(RelationType.Replace);
+        if (bundledEdit?.content) {
+            const replacement = mapper(bundledEdit);
+            // XXX: it's worth noting that the spec says we should only respect encrypted edits if, once decrypted, the
+            //   replacement has a `m.new_content` property. The problem is that we haven't yet decrypted the replacement
+            //   (it should be happening in the background), so we can't enforce this. Possibly we should for decryption
+            //   to complete, but that sounds a bit racy. For now, we just assume it's ok.
+            event.makeReplaced(replacement);
+        }
+
         const thread = room?.findThreadForEvent(event);
         if (thread) {
             event.setThread(thread);

src/extensible_events_v1/ExtensibleEvent.ts

@@ -0,0 +1,58 @@
+/*
+Copyright 2021 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { ExtensibleEventType, IPartialEvent } from "../@types/extensible_events";
+
+/**
+ * Represents an Extensible Event in Matrix.
+ */
+export abstract class ExtensibleEvent<TContent extends object = object> {
+    protected constructor(public readonly wireFormat: IPartialEvent<TContent>) {}
+
+    /**
+     * Shortcut to wireFormat.content
+     */
+    public get wireContent(): TContent {
+        return this.wireFormat.content;
+    }
+
+    /**
+     * Serializes the event into a format which can be used to send the
+     * event to the room.
+     * @returns The serialized event.
+     */
+    public abstract serialize(): IPartialEvent<object>;
+
+    /**
+     * Determines if this event is equivalent to the provided event type.
+     * This is recommended over `instanceof` checks due to issues in the JS
+     * runtime (and layering of dependencies in some projects).
+     *
+     * Implementations should pass this check off to their super classes
+     * if their own checks fail. Some primary implementations do not extend
+     * fallback classes given they support the primary type first. Thus,
+     * those classes may return false if asked about their fallback
+     * representation.
+     *
+     * Note that this only checks primary event types: legacy events, like
+     * m.room.message, should/will fail this check.
+     * @param primaryEventType - The (potentially namespaced) event
+     * type.
+     * @returns True if this event *could* be represented as the
+     * given type.
+     */
+    public abstract isEquivalentTo(primaryEventType: ExtensibleEventType): boolean;
+}

src/extensible_events_v1/InvalidEventError.ts

@@ -0,0 +1,24 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/**
+ * Thrown when an event is unforgivably unparsable.
+ */
+export class InvalidEventError extends Error {
+    public constructor(message: string) {
+        super(message);
+    }
+}

src/extensible_events_v1/MessageEvent.ts

@@ -0,0 +1,145 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { Optional } from "matrix-events-sdk";
+
+import { ExtensibleEvent } from "./ExtensibleEvent";
+import {
+    ExtensibleEventType,
+    IMessageRendering,
+    IPartialEvent,
+    isEventTypeSame,
+    M_HTML,
+    M_MESSAGE,
+    ExtensibleAnyMessageEventContent,
+    M_TEXT,
+} from "../@types/extensible_events";
+import { isOptionalAString, isProvided } from "./utilities";
+import { InvalidEventError } from "./InvalidEventError";
+
+/**
+ * Represents a message event. Message events are the simplest form of event with
+ * just text (optionally of different mimetypes, like HTML).
+ *
+ * Message events can additionally be an Emote or Notice, though typically those
+ * are represented as EmoteEvent and NoticeEvent respectively.
+ */
+export class MessageEvent extends ExtensibleEvent<ExtensibleAnyMessageEventContent> {
+    /**
+     * The default text for the event.
+     */
+    public readonly text: string;
+
+    /**
+     * The default HTML for the event, if provided.
+     */
+    public readonly html: Optional<string>;
+
+    /**
+     * All the different renderings of the message. Note that this is the same
+     * format as an m.message body but may contain elements not found directly
+     * in the event content: this is because this is interpreted based off the
+     * other information available in the event.
+     */
+    public readonly renderings: IMessageRendering[];
+
+    /**
+     * Creates a new MessageEvent from a pure format. Note that the event is
+     * *not* parsed here: it will be treated as a literal m.message primary
+     * typed event.
+     * @param wireFormat - The event.
+     */
+    public constructor(wireFormat: IPartialEvent<ExtensibleAnyMessageEventContent>) {
+        super(wireFormat);
+
+        const mmessage = M_MESSAGE.findIn(this.wireContent);
+        const mtext = M_TEXT.findIn<string>(this.wireContent);
+        const mhtml = M_HTML.findIn<string>(this.wireContent);
+        if (isProvided(mmessage)) {
+            if (!Array.isArray(mmessage)) {
+                throw new InvalidEventError("m.message contents must be an array");
+            }
+            const text = mmessage.find((r) => !isProvided(r.mimetype) || r.mimetype === "text/plain");
+            const html = mmessage.find((r) => r.mimetype === "text/html");
+
+            if (!text) throw new InvalidEventError("m.message is missing a plain text representation");
+
+            this.text = text.body;
+            this.html = html?.body;
+            this.renderings = mmessage;
+        } else if (isOptionalAString(mtext)) {
+            this.text = mtext;
+            this.html = mhtml;
+            this.renderings = [{ body: mtext, mimetype: "text/plain" }];
+            if (this.html) {
+                this.renderings.push({ body: this.html, mimetype: "text/html" });
+            }
+        } else {
+            throw new InvalidEventError("Missing textual representation for event");
+        }
+    }
+
+    public isEquivalentTo(primaryEventType: ExtensibleEventType): boolean {
+        return isEventTypeSame(primaryEventType, M_MESSAGE);
+    }
+
+    protected serializeMMessageOnly(): ExtensibleAnyMessageEventContent {
+        let messageRendering: ExtensibleAnyMessageEventContent = {
+            [M_MESSAGE.name]: this.renderings,
+        };
+
+        // Use the shorthand if it's just a simple text event
+        if (this.renderings.length === 1) {
+            const mime = this.renderings[0].mimetype;
+            if (mime === undefined || mime === "text/plain") {
+                messageRendering = {
+                    [M_TEXT.name]: this.renderings[0].body,
+                };
+            }
+        }
+
+        return messageRendering;
+    }
+
+    public serialize(): IPartialEvent<object> {
+        return {
+            type: "m.room.message",
+            content: {
+                ...this.serializeMMessageOnly(),
+                body: this.text,
+                msgtype: "m.text",
+                format: this.html ? "org.matrix.custom.html" : undefined,
+                formatted_body: this.html ?? undefined,
+            },
+        };
+    }
+
+    /**
+     * Creates a new MessageEvent from text and HTML.
+     * @param text - The text.
+     * @param html - Optional HTML.
+     * @returns The representative message event.
+     */
+    public static from(text: string, html?: string): MessageEvent {
+        return new MessageEvent({
+            type: M_MESSAGE.name,
+            content: {
+                [M_TEXT.name]: text,
+                [M_HTML.name]: html,
+            },
+        });
+    }
+}

src/extensible_events_v1/PollEndEvent.ts

@@ -0,0 +1,97 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import {
+    ExtensibleEventType,
+    IPartialEvent,
+    isEventTypeSame,
+    M_TEXT,
+    REFERENCE_RELATION,
+} from "../@types/extensible_events";
+import { M_POLL_END, PollEndEventContent } from "../@types/polls";
+import { ExtensibleEvent } from "./ExtensibleEvent";
+import { InvalidEventError } from "./InvalidEventError";
+import { MessageEvent } from "./MessageEvent";
+
+/**
+ * Represents a poll end/closure event.
+ */
+export class PollEndEvent extends ExtensibleEvent<PollEndEventContent> {
+    /**
+     * The poll start event ID referenced by the response.
+     */
+    public readonly pollEventId: string;
+
+    /**
+     * The closing message for the event.
+     */
+    public readonly closingMessage: MessageEvent;
+
+    /**
+     * Creates a new PollEndEvent from a pure format. Note that the event is *not*
+     * parsed here: it will be treated as a literal m.poll.response primary typed event.
+     * @param wireFormat - The event.
+     */
+    public constructor(wireFormat: IPartialEvent<PollEndEventContent>) {
+        super(wireFormat);
+
+        const rel = this.wireContent["m.relates_to"];
+        if (!REFERENCE_RELATION.matches(rel?.rel_type) || typeof rel?.event_id !== "string") {
+            throw new InvalidEventError("Relationship must be a reference to an event");
+        }
+
+        this.pollEventId = rel.event_id;
+        this.closingMessage = new MessageEvent(this.wireFormat);
+    }
+
+    public isEquivalentTo(primaryEventType: ExtensibleEventType): boolean {
+        return isEventTypeSame(primaryEventType, M_POLL_END);
+    }
+
+    public serialize(): IPartialEvent<object> {
+        return {
+            type: M_POLL_END.name,
+            content: {
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                    event_id: this.pollEventId,
+                },
+                [M_POLL_END.name]: {},
+                ...this.closingMessage.serialize().content,
+            },
+        };
+    }
+
+    /**
+     * Creates a new PollEndEvent from a poll event ID.
+     * @param pollEventId - The poll start event ID.
+     * @param message - A closing message, typically revealing the top answer.
+     * @returns The representative poll closure event.
+     */
+    public static from(pollEventId: string, message: string): PollEndEvent {
+        return new PollEndEvent({
+            type: M_POLL_END.name,
+            content: {
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                    event_id: pollEventId,
+                },
+                [M_POLL_END.name]: {},
+                [M_TEXT.name]: message,
+            },
+        });
+    }
+}

src/extensible_events_v1/PollResponseEvent.ts

@@ -0,0 +1,143 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { ExtensibleEvent } from "./ExtensibleEvent";
+import { M_POLL_RESPONSE, PollResponseEventContent, PollResponseSubtype } from "../@types/polls";
+import { ExtensibleEventType, IPartialEvent, isEventTypeSame, REFERENCE_RELATION } from "../@types/extensible_events";
+import { InvalidEventError } from "./InvalidEventError";
+import { PollStartEvent } from "./PollStartEvent";
+
+/**
+ * Represents a poll response event.
+ */
+export class PollResponseEvent extends ExtensibleEvent<PollResponseEventContent> {
+    private internalAnswerIds: string[] = [];
+    private internalSpoiled = false;
+
+    /**
+     * The provided answers for the poll. Note that this may be falsy/unpredictable if
+     * the `spoiled` property is true.
+     */
+    public get answerIds(): string[] {
+        return this.internalAnswerIds;
+    }
+
+    /**
+     * The poll start event ID referenced by the response.
+     */
+    public readonly pollEventId: string;
+
+    /**
+     * Whether the vote is spoiled.
+     */
+    public get spoiled(): boolean {
+        return this.internalSpoiled;
+    }
+
+    /**
+     * Creates a new PollResponseEvent from a pure format. Note that the event is *not*
+     * parsed here: it will be treated as a literal m.poll.response primary typed event.
+     *
+     * To validate the response against a poll, call `validateAgainst` after creation.
+     * @param wireFormat - The event.
+     */
+    public constructor(wireFormat: IPartialEvent<PollResponseEventContent>) {
+        super(wireFormat);
+
+        const rel = this.wireContent["m.relates_to"];
+        if (!REFERENCE_RELATION.matches(rel?.rel_type) || typeof rel?.event_id !== "string") {
+            throw new InvalidEventError("Relationship must be a reference to an event");
+        }
+
+        this.pollEventId = rel.event_id;
+        this.validateAgainst(null);
+    }
+
+    /**
+     * Validates the poll response using the poll start event as a frame of reference. This
+     * is used to determine if the vote is spoiled, whether the answers are valid, etc.
+     * @param poll - The poll start event.
+     */
+    public validateAgainst(poll: PollStartEvent | null): void {
+        const response = M_POLL_RESPONSE.findIn<PollResponseSubtype>(this.wireContent);
+        if (!Array.isArray(response?.answers)) {
+            this.internalSpoiled = true;
+            this.internalAnswerIds = [];
+            return;
+        }
+
+        let answers = response?.answers ?? [];
+        if (answers.some((a) => typeof a !== "string") || answers.length === 0) {
+            this.internalSpoiled = true;
+            this.internalAnswerIds = [];
+            return;
+        }
+
+        if (poll) {
+            if (answers.some((a) => !poll.answers.some((pa) => pa.id === a))) {
+                this.internalSpoiled = true;
+                this.internalAnswerIds = [];
+                return;
+            }
+
+            answers = answers.slice(0, poll.maxSelections);
+        }
+
+        this.internalAnswerIds = answers;
+        this.internalSpoiled = false;
+    }
+
+    public isEquivalentTo(primaryEventType: ExtensibleEventType): boolean {
+        return isEventTypeSame(primaryEventType, M_POLL_RESPONSE);
+    }
+
+    public serialize(): IPartialEvent<object> {
+        return {
+            type: M_POLL_RESPONSE.name,
+            content: {
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                    event_id: this.pollEventId,
+                },
+                [M_POLL_RESPONSE.name]: {
+                    answers: this.spoiled ? undefined : this.answerIds,
+                },
+            },
+        };
+    }
+
+    /**
+     * Creates a new PollResponseEvent from a set of answers. To spoil the vote, pass an empty
+     * answers array.
+     * @param answers - The user's answers. Should be valid from a poll's answer IDs.
+     * @param pollEventId - The poll start event ID.
+     * @returns The representative poll response event.
+     */
+    public static from(answers: string[], pollEventId: string): PollResponseEvent {
+        return new PollResponseEvent({
+            type: M_POLL_RESPONSE.name,
+            content: {
+                "m.relates_to": {
+                    rel_type: REFERENCE_RELATION.name,
+                    event_id: pollEventId,
+                },
+                [M_POLL_RESPONSE.name]: {
+                    answers: answers,
+                },
+            },
+        });
+    }
+}

src/extensible_events_v1/PollStartEvent.ts

@@ -0,0 +1,207 @@
+/*
+Copyright 2022 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { NamespacedValue } from "matrix-events-sdk";
+
+import { MessageEvent } from "./MessageEvent";
+import { ExtensibleEventType, IPartialEvent, isEventTypeSame, M_TEXT } from "../@types/extensible_events";
+import {
+    KnownPollKind,
+    M_POLL_KIND_DISCLOSED,
+    M_POLL_KIND_UNDISCLOSED,
+    M_POLL_START,
+    PollStartEventContent,
+    PollStartSubtype,
+    PollAnswer,
+} from "../@types/polls";
+import { InvalidEventError } from "./InvalidEventError";
+import { ExtensibleEvent } from "./ExtensibleEvent";
+
+/**
+ * Represents a poll answer. Note that this is represented as a subtype and is
+ * not registered as a parsable event - it is implied for usage exclusively
+ * within the PollStartEvent parsing.
+ */
+export class PollAnswerSubevent extends MessageEvent {
+    /**
+     * The answer ID.
+     */
+    public readonly id: string;
+
+    public constructor(wireFormat: IPartialEvent<PollAnswer>) {
+        super(wireFormat);
+
+        const id = wireFormat.content.id;
+        if (!id || typeof id !== "string") {
+            throw new InvalidEventError("Answer ID must be a non-empty string");
+        }
+        this.id = id;
+    }
+
+    public serialize(): IPartialEvent<object> {
+        return {
+            type: "org.matrix.sdk.poll.answer",
+            content: {
+                id: this.id,
+                ...this.serializeMMessageOnly(),
+            },
+        };
+    }
+
+    /**
+     * Creates a new PollAnswerSubevent from ID and text.
+     * @param id - The answer ID (unique within the poll).
+     * @param text - The text.
+     * @returns The representative answer.
+     */
+    public static from(id: string, text: string): PollAnswerSubevent {
+        return new PollAnswerSubevent({
+            type: "org.matrix.sdk.poll.answer",
+            content: {
+                id: id,
+                [M_TEXT.name]: text,
+            },
+        });
+    }
+}
+
+/**
+ * Represents a poll start event.
+ */
+export class PollStartEvent extends ExtensibleEvent<PollStartEventContent> {
+    /**
+     * The question being asked, as a MessageEvent node.
+     */
+    public readonly question: MessageEvent;
+
+    /**
+     * The interpreted kind of poll. Note that this will infer a value that is known to the
+     * SDK rather than verbatim - this means unknown types will be represented as undisclosed
+     * polls.
+     *
+     * To get the raw kind, use rawKind.
+     */
+    public readonly kind: KnownPollKind;
+
+    /**
+     * The true kind as provided by the event sender. Might not be valid.
+     */
+    public readonly rawKind: string;
+
+    /**
+     * The maximum number of selections a user is allowed to make.
+     */
+    public readonly maxSelections: number;
+
+    /**
+     * The possible answers for the poll.
+     */
+    public readonly answers: PollAnswerSubevent[];
+
+    /**
+     * Creates a new PollStartEvent from a pure format. Note that the event is *not*
+     * parsed here: it will be treated as a literal m.poll.start primary typed event.
+     * @param wireFormat - The event.
+     */
+    public constructor(wireFormat: IPartialEvent<PollStartEventContent>) {
+        super(wireFormat);
+
+        const poll = M_POLL_START.findIn<PollStartSubtype>(this.wireContent);
+
+        if (!poll?.question) {
+            throw new InvalidEventError("A question is required");
+        }
+
+        this.question = new MessageEvent({ type: "org.matrix.sdk.poll.question", content: poll.question });
+
+        this.rawKind = poll.kind;
+        if (M_POLL_KIND_DISCLOSED.matches(this.rawKind)) {
+            this.kind = M_POLL_KIND_DISCLOSED;
+        } else {
+            this.kind = M_POLL_KIND_UNDISCLOSED; // default & assumed value
+        }
+
+        this.maxSelections =
+            Number.isFinite(poll.max_selections) && poll.max_selections! > 0 ? poll.max_selections! : 1;
+
+        if (!Array.isArray(poll.answers)) {
+            throw new InvalidEventError("Poll answers must be an array");
+        }
+        const answers = poll.answers.slice(0, 20).map(
+            (a) =>
+                new PollAnswerSubevent({
+                    type: "org.matrix.sdk.poll.answer",
+                    content: a,
+                }),
+        );
+        if (answers.length <= 0) {
+            throw new InvalidEventError("No answers available");
+        }
+        this.answers = answers;
+    }
+
+    public isEquivalentTo(primaryEventType: ExtensibleEventType): boolean {
+        return isEventTypeSame(primaryEventType, M_POLL_START);
+    }
+
+    public serialize(): IPartialEvent<object> {
+        return {
+            type: M_POLL_START.name,
+            content: {
+                [M_POLL_START.name]: {
+                    question: this.question.serialize().content,
+                    kind: this.rawKind,
+                    max_selections: this.maxSelections,
+                    answers: this.answers.map((a) => a.serialize().content),
+                },
+                [M_TEXT.name]: `${this.question.text}\n${this.answers.map((a, i) => `${i + 1}. ${a.text}`).join("\n")}`,
+            },
+        };
+    }
+
+    /**
+     * Creates a new PollStartEvent from question, answers, and metadata.
+     * @param question - The question to ask.
+     * @param answers - The answers. Should be unique within each other.
+     * @param kind - The kind of poll.
+     * @param maxSelections - The maximum number of selections. Must be 1 or higher.
+     * @returns The representative poll start event.
+     */
+    public static from(
+        question: string,
+        answers: string[],
+        kind: KnownPollKind | string,
+        maxSelections = 1,
+    ): PollStartEvent {
+        return new PollStartEvent({
+            type: M_POLL_START.name,
+            content: {
+                [M_TEXT.name]: question, // unused by parsing
+                [M_POLL_START.name]: {
+                    question: { [M_TEXT.name]: question },
+                    kind: kind instanceof NamespacedValue ? kind.name : kind,
+                    max_selections: maxSelections,
+                    answers: answers.map((a) => ({ id: makeId(), [M_TEXT.name]: a })),
+                },
+            },
+        });
+    }
+}
+
+const LETTERS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+function makeId(): string {
+    return [...Array(16)].map(() => LETTERS.charAt(Math.floor(Math.random() * LETTERS.length))).join("");
+}

src/extensible_events_v1/utilities.ts

@@ -0,0 +1,35 @@
+/*
+Copyright 2021 - 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { Optional } from "matrix-events-sdk";
+
+/**
+ * Determines if the given optional was provided a value.
+ * @param s - The optional to test.
+ * @returns True if the value is defined.
+ */
+export function isProvided<T>(s: Optional<T>): boolean {
+    return s !== null && s !== undefined;
+}
+
+/**
+ * Determines if the given optional string is a defined string.
+ * @param s - The input string.
+ * @returns True if the input is a defined string.
+ */
+export function isOptionalAString(s: Optional<string>): s is string {
+    return isProvided(s) && typeof s === "string";
+}

src/interactive-auth.ts

@@ -24,7 +24,7 @@ import { MatrixError } from "./http-api";
 const EMAIL_STAGE_TYPE = "m.login.email.identity";
 const MSISDN_STAGE_TYPE = "m.login.msisdn";
 
-interface IFlow {
+export interface UIAFlow {
     stages: AuthType[];
 }
 
@@ -48,8 +48,8 @@ export interface IAuthData {
     session?: string;
     type?: string;
     completed?: string[];
-    flows?: IFlow[];
-    available_flows?: IFlow[];
+    flows?: UIAFlow[];
+    available_flows?: UIAFlow[];
     stages?: string[];
     required_stages?: AuthType[];
     params?: Record<string, Record<string, any>>;
@@ -101,7 +101,7 @@ class NoAuthFlowFoundError extends Error {
     public name = "NoAuthFlowFoundError";
 
     // eslint-disable-next-line @typescript-eslint/naming-convention, camelcase
-    public constructor(m: string, public readonly required_stages: string[], public readonly flows: IFlow[]) {
+    public constructor(m: string, public readonly required_stages: string[], public readonly flows: UIAFlow[]) {
         super(m);
     }
 }
@@ -198,7 +198,7 @@ export class InteractiveAuth {
     private emailSid?: string;
     private requestingEmailToken = false;
     private attemptAuthDeferred: IDeferred<IAuthData> | null = null;
-    private chosenFlow: IFlow | null = null;
+    private chosenFlow: UIAFlow | null = null;
     private currentStage: string | null = null;
 
     private emailAttempt = 1;
@@ -320,7 +320,7 @@ export class InteractiveAuth {
         return this.data.params?.[loginType];
     }
 
-    public getChosenFlow(): IFlow | null {
+    public getChosenFlow(): UIAFlow | null {
         return this.chosenFlow;
     }
 
@@ -573,7 +573,7 @@ export class InteractiveAuth {
      * @returns flow
      * @throws {@link NoAuthFlowFoundError} If no suitable authentication flow can be found
      */
-    private chooseFlow(): IFlow {
+    private chooseFlow(): UIAFlow {
         const flows = this.data.flows || [];
 
         // we've been given an email or we've already done an email part
@@ -610,7 +610,7 @@ export class InteractiveAuth {
      * @internal
      * @returns login type
      */
-    private firstUncompletedStage(flow: IFlow): AuthType | undefined {
+    private firstUncompletedStage(flow: UIAFlow): AuthType | undefined {
         const completed = this.data.completed || [];
         return flow.stages.find((stageType) => !completed.includes(stageType));
     }

src/matrix.ts

@@ -34,6 +34,7 @@ export * from "./models/event";
 export * from "./models/room";
 export * from "./models/event-timeline";
 export * from "./models/event-timeline-set";
+export * from "./models/poll";
 export * from "./models/room-member";
 export * from "./models/room-state";
 export * from "./models/user";

src/models/event.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2015 - 2022 The Matrix.org Foundation C.I.C.
+Copyright 2015 - 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -267,7 +267,6 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
     private txnId?: string;
 
     /**
-     * @experimental
      * A reference to the thread this event belongs to
      */
     private thread?: Thread;
@@ -546,7 +545,6 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
     }
 
     /**
-     * @experimental
      * Get the event ID of the thread head
      */
     public get threadRootId(): string | undefined {
@@ -559,7 +557,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
     }
 
     /**
-     * @experimental
+     * A helper to check if an event is a thread's head or not
      */
     public get isThreadRoot(): boolean {
         const threadDetails = this.getServerAggregatedRelation<IThreadBundledRelationship>(THREAD_RELATION_TYPE.name);
@@ -1557,7 +1555,8 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
     }
 
     /**
-     * @experimental
+     * Set the instance of a thread associated with the current event
+     * @param thread - the thread
      */
     public setThread(thread?: Thread): void {
         if (this.thread) {
@@ -1571,7 +1570,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
     }
 
     /**
-     * @experimental
+     * Get the instance of the thread associated with the current event
      */
     public getThread(): Thread | undefined {
         return this.thread;

src/models/poll.ts

@@ -0,0 +1,234 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { M_POLL_END, M_POLL_RESPONSE } from "../@types/polls";
+import { MatrixClient } from "../client";
+import { PollStartEvent } from "../extensible_events_v1/PollStartEvent";
+import { MatrixEvent } from "./event";
+import { Relations } from "./relations";
+import { Room } from "./room";
+import { TypedEventEmitter } from "./typed-event-emitter";
+
+export enum PollEvent {
+    New = "Poll.new",
+    End = "Poll.end",
+    Update = "Poll.update",
+    Responses = "Poll.Responses",
+    Destroy = "Poll.Destroy",
+}
+
+export type PollEventHandlerMap = {
+    [PollEvent.Update]: (event: MatrixEvent, poll: Poll) => void;
+    [PollEvent.Destroy]: (pollIdentifier: string) => void;
+    [PollEvent.End]: () => void;
+    [PollEvent.Responses]: (responses: Relations) => void;
+};
+
+const filterResponseRelations = (
+    relationEvents: MatrixEvent[],
+    pollEndTimestamp: number,
+): {
+    responseEvents: MatrixEvent[];
+} => {
+    const responseEvents = relationEvents.filter((event) => {
+        if (event.isDecryptionFailure()) {
+            // @TODO(kerrya) PSG-1023 track and return these
+            return;
+        }
+        return (
+            M_POLL_RESPONSE.matches(event.getType()) &&
+            // From MSC3381:
+            // "Votes sent on or before the end event's timestamp are valid votes"
+            event.getTs() <= pollEndTimestamp
+        );
+    });
+
+    return { responseEvents };
+};
+
+export class Poll extends TypedEventEmitter<Exclude<PollEvent, PollEvent.New>, PollEventHandlerMap> {
+    public readonly roomId: string;
+    public readonly pollEvent: PollStartEvent;
+    private _isFetchingResponses = false;
+    private relationsNextBatch: string | undefined;
+    private responses: null | Relations = null;
+    private endEvent: MatrixEvent | undefined;
+
+    public constructor(public readonly rootEvent: MatrixEvent, private matrixClient: MatrixClient, private room: Room) {
+        super();
+        if (!this.rootEvent.getRoomId() || !this.rootEvent.getId()) {
+            throw new Error("Invalid poll start event.");
+        }
+        this.roomId = this.rootEvent.getRoomId()!;
+        this.pollEvent = this.rootEvent.unstableExtensibleEvent as unknown as PollStartEvent;
+    }
+
+    public get pollId(): string {
+        return this.rootEvent.getId()!;
+    }
+
+    public get isEnded(): boolean {
+        return !!this.endEvent;
+    }
+
+    public get isFetchingResponses(): boolean {
+        return this._isFetchingResponses;
+    }
+
+    public async getResponses(): Promise<Relations> {
+        // if we have already fetched some responses
+        // just return them
+        if (this.responses) {
+            return this.responses;
+        }
+
+        // if there is no fetching in progress
+        // start fetching
+        if (!this.isFetchingResponses) {
+            await this.fetchResponses();
+        }
+        // return whatever responses we got from the first page
+        return this.responses!;
+    }
+
+    /**
+     *
+     * @param event - event with a relation to the rootEvent
+     * @returns void
+     */
+    public onNewRelation(event: MatrixEvent): void {
+        if (M_POLL_END.matches(event.getType()) && this.validateEndEvent(event)) {
+            this.endEvent = event;
+            this.refilterResponsesOnEnd();
+            this.emit(PollEvent.End);
+        }
+
+        // wait for poll responses to be initialised
+        if (!this.responses) {
+            return;
+        }
+
+        const pollEndTimestamp = this.endEvent?.getTs() || Number.MAX_SAFE_INTEGER;
+        const { responseEvents } = filterResponseRelations([event], pollEndTimestamp);
+
+        if (responseEvents.length) {
+            responseEvents.forEach((event) => {
+                this.responses!.addEvent(event);
+            });
+            this.emit(PollEvent.Responses, this.responses);
+        }
+    }
+
+    private async fetchResponses(): Promise<void> {
+        this._isFetchingResponses = true;
+
+        // we want:
+        // - stable and unstable M_POLL_RESPONSE
+        // - stable and unstable M_POLL_END
+        // so make one api call and filter by event type client side
+        const allRelations = await this.matrixClient.relations(
+            this.roomId,
+            this.rootEvent.getId()!,
+            "m.reference",
+            undefined,
+            {
+                from: this.relationsNextBatch || undefined,
+            },
+        );
+
+        const responses =
+            this.responses ||
+            new Relations("m.reference", M_POLL_RESPONSE.name, this.matrixClient, [M_POLL_RESPONSE.altName!]);
+
+        const pollEndEvent = allRelations.events.find((event) => M_POLL_END.matches(event.getType()));
+        if (this.validateEndEvent(pollEndEvent)) {
+            this.endEvent = pollEndEvent;
+            this.refilterResponsesOnEnd();
+            this.emit(PollEvent.End);
+        }
+
+        const pollCloseTimestamp = this.endEvent?.getTs() || Number.MAX_SAFE_INTEGER;
+
+        const { responseEvents } = filterResponseRelations(allRelations.events, pollCloseTimestamp);
+
+        responseEvents.forEach((event) => {
+            responses.addEvent(event);
+        });
+
+        this.relationsNextBatch = allRelations.nextBatch ?? undefined;
+        this.responses = responses;
+
+        // while there are more pages of relations
+        // fetch them
+        if (this.relationsNextBatch) {
+            // don't await
+            // we want to return the first page as soon as possible
+            this.fetchResponses();
+        } else {
+            // no more pages
+            this._isFetchingResponses = false;
+        }
+
+        // emit after updating _isFetchingResponses state
+        this.emit(PollEvent.Responses, this.responses);
+    }
+
+    /**
+     * Only responses made before the poll ended are valid
+     * Refilter after an end event is recieved
+     * To ensure responses are valid
+     */
+    private refilterResponsesOnEnd(): void {
+        if (!this.responses) {
+            return;
+        }
+
+        const pollEndTimestamp = this.endEvent?.getTs() || Number.MAX_SAFE_INTEGER;
+        this.responses.getRelations().forEach((event) => {
+            if (event.getTs() > pollEndTimestamp) {
+                this.responses?.removeEvent(event);
+            }
+        });
+
+        this.emit(PollEvent.Responses, this.responses);
+    }
+
+    private validateEndEvent(endEvent?: MatrixEvent): boolean {
+        if (!endEvent) {
+            return false;
+        }
+        /**
+         * Repeated end events are ignored -
+         * only the first (valid) closure event by origin_server_ts is counted.
+         */
+        if (this.endEvent && this.endEvent.getTs() < endEvent.getTs()) {
+            return false;
+        }
+
+        /**
+         * MSC3381
+         * If a m.poll.end event is received from someone other than the poll creator or user with permission to redact
+         * others' messages in the room, the event must be ignored by clients due to being invalid.
+         */
+        const roomCurrentState = this.room.currentState;
+        const endEventSender = endEvent.getSender();
+        return (
+            !!endEventSender &&
+            (endEventSender === this.rootEvent.getSender() ||
+                roomCurrentState.maySendRedactionForEvent(this.rootEvent, endEventSender))
+        );
+    }
+}

src/models/relations.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2019, 2021 The Matrix.org Foundation C.I.C.
+Copyright 2019, 2021, 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -122,7 +122,7 @@ export class Relations extends TypedEventEmitter<RelationsEvent, EventHandlerMap
      *
      * @param event - The relation event to remove.
      */
-    private async removeEvent(event: MatrixEvent): Promise<void> {
+    public async removeEvent(event: MatrixEvent): Promise<void> {
         if (!this.relations.has(event)) {
             return;
         }

src/models/room-state.ts

@@ -964,6 +964,55 @@ export class RoomState extends TypedEventEmitter<EmittedEvents, EventHandlerMap>
         return guestAccessContent["guest_access"] || GuestAccess.Forbidden;
     }
 
+    /**
+     * Find the predecessor room based on this room state.
+     *
+     * @param msc3946ProcessDynamicPredecessor - if true, look for an
+     * m.room.predecessor state event and use it if found (MSC3946).
+     * @returns null if this room has no predecessor. Otherwise, returns
+     * the roomId and last eventId of the predecessor room.
+     * If msc3946ProcessDynamicPredecessor is true, use m.predecessor events
+     * as well as m.room.create events to find predecessors.
+     * Note: if an m.predecessor event is used, eventId is null since those
+     * events do not include an event_id property.
+     */
+    public findPredecessor(
+        msc3946ProcessDynamicPredecessor = false,
+    ): { roomId: string; eventId: string | null } | null {
+        // Note: the tests for this function are against Room.findPredecessor,
+        // which just calls through to here.
+
+        if (msc3946ProcessDynamicPredecessor) {
+            const predecessorEvent = this.getStateEvents(EventType.RoomPredecessor, "");
+            if (predecessorEvent) {
+                const roomId = predecessorEvent.getContent()["predecessor_room_id"];
+                let eventId = predecessorEvent.getContent()["last_known_event_id"];
+                if (typeof eventId !== "string") {
+                    eventId = null;
+                }
+                if (typeof roomId === "string") {
+                    return { roomId, eventId };
+                }
+            }
+        }
+
+        const createEvent = this.getStateEvents(EventType.RoomCreate, "");
+        if (createEvent) {
+            const predecessor = createEvent.getContent()["predecessor"];
+            if (predecessor) {
+                const roomId = predecessor["room_id"];
+                if (typeof roomId === "string") {
+                    let eventId = predecessor["event_id"];
+                    if (typeof eventId !== "string" || eventId === "") {
+                        eventId = null;
+                    }
+                    return { roomId, eventId };
+                }
+            }
+        }
+        return null;
+    }
+
     private updateThirdPartyTokenCache(memberEvent: MatrixEvent): void {
         if (!memberEvent.getContent().third_party_invite) {
             return;

src/models/room.ts

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { Optional } from "matrix-events-sdk";
+import { M_POLL_START, Optional } from "matrix-events-sdk";
 
 import {
     EventTimelineSet,
@@ -64,7 +64,7 @@ import {
 import { IStateEventWithRoomId } from "../@types/search";
 import { RelationsContainer } from "./relations-container";
 import { ReadReceipt, synthesizeReceipt } from "./read-receipt";
-import { Feature, ServerSupport } from "../feature";
+import { Poll, PollEvent } from "./poll";
 
 // These constants are used as sane defaults when the homeserver doesn't support
 // the m.room_versions capability. In practice, KNOWN_SAFE_ROOM_VERSION should be
@@ -162,7 +162,8 @@ export type RoomEmittedEvents =
     | BeaconEvent.New
     | BeaconEvent.Update
     | BeaconEvent.Destroy
-    | BeaconEvent.LivenessChange;
+    | BeaconEvent.LivenessChange
+    | PollEvent.New;
 
 export type RoomEventHandlerMap = {
     /**
@@ -289,6 +290,11 @@ export type RoomEventHandlerMap = {
     [RoomEvent.UnreadNotifications]: (unreadNotifications?: NotificationCount, threadId?: string) => void;
     [RoomEvent.TimelineRefresh]: (room: Room, eventTimelineSet: EventTimelineSet) => void;
     [ThreadEvent.New]: (thread: Thread, toStartOfTimeline: boolean) => void;
+    /**
+     * Fires when a new poll instance is added to the room state
+     * @param poll - the new poll
+     */
+    [PollEvent.New]: (poll: Poll) => void;
 } & Pick<ThreadHandlerMap, ThreadEvent.Update | ThreadEvent.NewReply | ThreadEvent.Delete> &
     EventTimelineSetHandlerMap &
     Pick<MatrixEventHandlerMap, MatrixEventEvent.BeforeRedaction> &
@@ -317,6 +323,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      */
     private unthreadedReceipts = new Map<string, Receipt>();
     private readonly timelineSets: EventTimelineSet[];
+    public readonly polls: Map<string, Poll> = new Map<string, Poll>();
     public readonly threadsTimelineSets: EventTimelineSet[] = [];
     // any filtered timeline sets we're maintaining for this room
     private readonly filteredTimelineSets: Record<string, EventTimelineSet> = {}; // filter_id: timelineSet
@@ -375,7 +382,8 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
     public readonly relations = new RelationsContainer(this.client, this);
 
     /**
-     * @experimental
+     * A collection of events known by the client
+     * This is not a comprehensive list of the threads that exist in this room
      */
     private threads = new Map<string, Thread>();
     public lastThread?: Thread;
@@ -475,7 +483,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
             return this.threadTimelineSetsPromise;
         }
 
-        if (this.client?.supportsExperimentalThreads()) {
+        if (this.client?.supportsThreads()) {
             try {
                 this.threadTimelineSetsPromise = Promise.all([
                     this.createThreadTimelineSet(),
@@ -1290,10 +1298,8 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      */
     public getUnreadNotificationCount(type = NotificationCountType.Total): number {
         let count = this.getRoomUnreadNotificationCount(type);
-        if (this.client.canSupport.get(Feature.ThreadUnreadNotifications) !== ServerSupport.Unsupported) {
-            for (const threadNotification of this.threadNotifications.values()) {
-                count += threadNotification[type] ?? 0;
-            }
+        for (const threadNotification of this.threadNotifications.values()) {
+            count += threadNotification[type] ?? 0;
         }
         return count;
     }
@@ -1322,7 +1328,6 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
     }
 
     /**
-     * @experimental
      * Get one of the notification counts for a thread
      * @param threadId - the root event ID
      * @param type - The type of notification count to get. default: 'total'
@@ -1334,7 +1339,6 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
     }
 
     /**
-     * @experimental
      * Checks if the current room has unread thread notifications
      * @returns
      */
@@ -1348,7 +1352,6 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
     }
 
     /**
-     * @experimental
      * Swet one of the notification count for a thread
      * @param threadId - the root event ID
      * @param type - The type of notification count to get. default: 'total'
@@ -1369,7 +1372,6 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
     }
 
     /**
-     * @experimental
      * @returns the notification count type for all the threads in the room
      */
     public get threadsAggregateNotificationType(): NotificationCountType | null {
@@ -1385,7 +1387,6 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
     }
 
     /**
-     * @experimental
      * Resets the thread notifications for this room
      */
     public resetThreadUnreadNotificationCount(notificationsToKeep?: string[]): void {
@@ -1545,14 +1546,16 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
     }
 
     /**
-     * @experimental
+     * Get the instance of the thread associated with the current event
+     * @param eventId - the ID of the current event
+     * @returns a thread instance if known
      */
     public getThread(eventId: string): Thread | null {
         return this.threads.get(eventId) ?? null;
     }
 
     /**
-     * @experimental
+     * Get all the known threads in the room
      */
     public getThreads(): Thread[] {
         return Array.from(this.threads.values());
@@ -1819,7 +1822,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      * Without server support that means fetching as much at once as the server allows us to.
      */
     public async fetchRoomThreads(): Promise<void> {
-        if (this.threadsReady || !this.client.supportsExperimentalThreads()) {
+        if (this.threadsReady || !this.client.supportsThreads()) {
             return;
         }
 
@@ -1890,6 +1893,38 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
         this.threadsReady = true;
     }
 
+    public async processPollEvents(events: MatrixEvent[]): Promise<void> {
+        const processPollStartEvent = (event: MatrixEvent): void => {
+            if (!M_POLL_START.matches(event.getType())) return;
+            try {
+                const poll = new Poll(event, this.client, this);
+                this.polls.set(event.getId()!, poll);
+                this.emit(PollEvent.New, poll);
+            } catch {}
+            // poll creation can fail for malformed poll start events
+        };
+
+        const processPollRelationEvent = (event: MatrixEvent): void => {
+            const relationEventId = event.relationEventId;
+            if (relationEventId && this.polls.has(relationEventId)) {
+                const poll = this.polls.get(relationEventId);
+                poll?.onNewRelation(event);
+            }
+        };
+
+        const processPollEvent = (event: MatrixEvent): void => {
+            processPollStartEvent(event);
+            processPollRelationEvent(event);
+        };
+
+        for (const event of events) {
+            try {
+                await this.client.decryptEventIfNeeded(event);
+                processPollEvent(event);
+            } catch {}
+        }
+    }
+
     /**
      * Fetch a single page of threadlist messages for the specific thread filter
      * @internal
@@ -1964,7 +1999,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
         shouldLiveInThread: boolean;
         threadId?: string;
     } {
-        if (!this.client?.supportsExperimentalThreads()) {
+        if (!this.client?.supportsThreads()) {
             return {
                 shouldLiveInRoom: true,
                 shouldLiveInThread: false,
@@ -2033,7 +2068,6 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
 
     /**
      * Adds events to a thread's timeline. Will fire "Thread.update"
-     * @experimental
      */
     public processThreadedEvents(events: MatrixEvent[], toStartOfTimeline: boolean): void {
         events.forEach(this.applyRedaction);
@@ -2662,7 +2696,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
         // Indices to the events array, for readability
         const ROOM = 0;
         const THREAD = 1;
-        if (this.client.supportsExperimentalThreads()) {
+        if (this.client.supportsThreads()) {
             const threadRoots = this.findThreadRoots(events);
             return events.reduce(
                 (memo, event: MatrixEvent) => {
@@ -2991,26 +3025,25 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
     }
 
     /**
-     * @returns the ID of the room that was this room's predecessor, or null if
-     *          this room has no predecessor.
+     * Find the predecessor of this room.
+     *
+     * @param msc3946ProcessDynamicPredecessor - if true, look for an
+     * m.room.predecessor state event and use it if found (MSC3946).
+     * @returns null if this room has no predecessor. Otherwise, returns
+     * the roomId and last eventId of the predecessor room.
+     * If msc3946ProcessDynamicPredecessor is true, use m.predecessor events
+     * as well as m.room.create events to find predecessors.
+     * Note: if an m.predecessor event is used, eventId is null since those
+     * events do not include an event_id property.
      */
-    public findPredecessorRoomId(): string | null {
+    public findPredecessor(
+        msc3946ProcessDynamicPredecessor = false,
+    ): { roomId: string; eventId: string | null } | null {
         const currentState = this.getLiveTimeline().getState(EventTimeline.FORWARDS);
         if (!currentState) {
             return null;
         }
-
-        const createEvent = currentState.getStateEvents(EventType.RoomCreate, "");
-        if (createEvent) {
-            const predecessor = createEvent.getContent()["predecessor"];
-            if (predecessor) {
-                const roomId = predecessor["room_id"];
-                if (roomId) {
-                    return roomId;
-                }
-            }
-        }
-        return null;
+        return currentState.findPredecessor(msc3946ProcessDynamicPredecessor);
     }
 
     private roomNameGenerator(state: RoomNameState): string {

src/models/thread.ts

@@ -69,9 +69,6 @@ export function determineFeatureSupport(stable: boolean, unstable: boolean): Fea
     }
 }
 
-/**
- * @experimental
- */
 export class Thread extends ReadReceipt<EmittedEvents, EventHandlerMap> {
     public static hasServerSideSupport = FeatureSupport.None;
     public static hasServerSideListSupport = FeatureSupport.None;
@@ -572,7 +569,7 @@ export class Thread extends ReadReceipt<EmittedEvents, EventHandlerMap> {
      */
     public getEventReadUpTo(userId: string, ignoreSynthesized?: boolean): string | null {
         const isCurrentUser = userId === this.client.getUserId();
-        const lastReply = this.timeline.at(-1);
+        const lastReply = this.timeline[this.timeline.length - 1];
         if (isCurrentUser && lastReply) {
             // If the last activity in a thread is prior to the first threaded read receipt
             // sent in the room (suggesting that it was sent before the user started

src/rust-crypto/KeyClaimManager.ts

@@ -0,0 +1,72 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { OlmMachine, UserId } from "@matrix-org/matrix-sdk-crypto-js";
+
+import { OutgoingRequestProcessor } from "./OutgoingRequestProcessor";
+
+/**
+ * KeyClaimManager: linearises calls to OlmMachine.getMissingSessions to avoid races
+ *
+ * We have one of these per `RustCrypto` (and hence per `MatrixClient`).
+ */
+export class KeyClaimManager {
+    private currentClaimPromise: Promise<void>;
+    private stopped = false;
+
+    public constructor(
+        private readonly olmMachine: OlmMachine,
+        private readonly outgoingRequestProcessor: OutgoingRequestProcessor,
+    ) {
+        this.currentClaimPromise = Promise.resolve();
+    }
+
+    /**
+     * Tell the KeyClaimManager to immediately stop processing requests.
+     *
+     * Any further calls, and any still in the queue, will fail with an error.
+     */
+    public stop(): void {
+        this.stopped = true;
+    }
+
+    /**
+     * Given a list of users, attempt to ensure that we have Olm Sessions active with each of their devices
+     *
+     * If we don't have an active olm session, we will claim a one-time key and start one.
+     *
+     * @param userList - list of userIDs to claim
+     */
+    public ensureSessionsForUsers(userList: Array<UserId>): Promise<void> {
+        // The Rust-SDK requires that we only have one getMissingSessions process in flight at once. This little dance
+        // ensures that, by only having one call to ensureSessionsForUsersInner active at once (and making them
+        // queue up in order).
+        const prom = this.currentClaimPromise.finally(() => this.ensureSessionsForUsersInner(userList));
+        this.currentClaimPromise = prom;
+        return prom;
+    }
+
+    private async ensureSessionsForUsersInner(userList: Array<UserId>): Promise<void> {
+        // bail out quickly if we've been stopped.
+        if (this.stopped) {
+            throw new Error(`Cannot ensure Olm sessions: shutting down`);
+        }
+        const claimRequest = await this.olmMachine.getMissingSessions(userList);
+        if (claimRequest) {
+            await this.outgoingRequestProcessor.makeOutgoingRequest(claimRequest);
+        }
+    }
+}

src/rust-crypto/OutgoingRequestProcessor.ts

@@ -0,0 +1,116 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import {
+    OlmMachine,
+    KeysBackupRequest,
+    KeysClaimRequest,
+    KeysQueryRequest,
+    KeysUploadRequest,
+    RoomMessageRequest,
+    SignatureUploadRequest,
+    ToDeviceRequest,
+} from "@matrix-org/matrix-sdk-crypto-js";
+
+import { logger } from "../logger";
+import { IHttpOpts, MatrixHttpApi, Method } from "../http-api";
+import { QueryDict } from "../utils";
+
+/**
+ * Common interface for all the request types returned by `OlmMachine.outgoingRequests`.
+ */
+export interface OutgoingRequest {
+    readonly id: string | undefined;
+    readonly type: number;
+}
+
+/**
+ * OutgoingRequestManager: turns `OutgoingRequest`s from the rust sdk into HTTP requests
+ *
+ * We have one of these per `RustCrypto` (and hence per `MatrixClient`), not that it does anything terribly complicated.
+ * It's responsible for:
+ *
+ *   * holding the reference to the `MatrixHttpApi`
+ *   * turning `OutgoingRequest`s from the rust backend into HTTP requests, and sending them
+ *   * sending the results of such requests back to the rust backend.
+ */
+export class OutgoingRequestProcessor {
+    public constructor(
+        private readonly olmMachine: OlmMachine,
+        private readonly http: MatrixHttpApi<IHttpOpts & { onlyData: true }>,
+    ) {}
+
+    public async makeOutgoingRequest(msg: OutgoingRequest): Promise<void> {
+        let resp: string;
+
+        /* refer https://docs.rs/matrix-sdk-crypto/0.6.0/matrix_sdk_crypto/requests/enum.OutgoingRequests.html
+         * for the complete list of request types
+         */
+        if (msg instanceof KeysUploadRequest) {
+            resp = await this.rawJsonRequest(Method.Post, "/_matrix/client/v3/keys/upload", {}, msg.body);
+        } else if (msg instanceof KeysQueryRequest) {
+            resp = await this.rawJsonRequest(Method.Post, "/_matrix/client/v3/keys/query", {}, msg.body);
+        } else if (msg instanceof KeysClaimRequest) {
+            resp = await this.rawJsonRequest(Method.Post, "/_matrix/client/v3/keys/claim", {}, msg.body);
+        } else if (msg instanceof SignatureUploadRequest) {
+            resp = await this.rawJsonRequest(Method.Post, "/_matrix/client/v3/keys/signatures/upload", {}, msg.body);
+        } else if (msg instanceof KeysBackupRequest) {
+            resp = await this.rawJsonRequest(Method.Put, "/_matrix/client/v3/room_keys/keys", {}, msg.body);
+        } else if (msg instanceof ToDeviceRequest) {
+            const path =
+                `/_matrix/client/v3/sendToDevice/${encodeURIComponent(msg.event_type)}/` +
+                encodeURIComponent(msg.txn_id);
+            resp = await this.rawJsonRequest(Method.Put, path, {}, msg.body);
+        } else if (msg instanceof RoomMessageRequest) {
+            const path =
+                `/_matrix/client/v3/room/${encodeURIComponent(msg.room_id)}/send/` +
+                `${encodeURIComponent(msg.event_type)}/${encodeURIComponent(msg.txn_id)}`;
+            resp = await this.rawJsonRequest(Method.Put, path, {}, msg.body);
+        } else {
+            logger.warn("Unsupported outgoing message", Object.getPrototypeOf(msg));
+            resp = "";
+        }
+
+        if (msg.id) {
+            await this.olmMachine.markRequestAsSent(msg.id, msg.type, resp);
+        }
+    }
+
+    private async rawJsonRequest(method: Method, path: string, queryParams: QueryDict, body: string): Promise<string> {
+        const opts = {
+            // inhibit the JSON stringification and parsing within HttpApi.
+            json: false,
+
+            // nevertheless, we are sending, and accept, JSON.
+            headers: {
+                "Content-Type": "application/json",
+                "Accept": "application/json",
+            },
+
+            // we use the full prefix
+            prefix: "",
+        };
+
+        try {
+            const response = await this.http.authedRequest<string>(method, path, queryParams, body, opts);
+            logger.info(`rust-crypto: successfully made HTTP request: ${method} ${path}`);
+            return response;
+        } catch (e) {
+            logger.warn(`rust-crypto: error making HTTP request: ${method} ${path}: ${e}`);
+            throw e;
+        }
+    }
+}

src/rust-crypto/RoomEncryptor.ts

@@ -0,0 +1,130 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { EncryptionSettings, OlmMachine, RoomId, UserId } from "@matrix-org/matrix-sdk-crypto-js";
+
+import { EventType } from "../@types/event";
+import { IContent, MatrixEvent } from "../models/event";
+import { Room } from "../models/room";
+import { logger, PrefixedLogger } from "../logger";
+import { KeyClaimManager } from "./KeyClaimManager";
+import { RoomMember } from "../models/room-member";
+
+/**
+ * RoomEncryptor: responsible for encrypting messages to a given room
+ */
+export class RoomEncryptor {
+    private readonly prefixedLogger: PrefixedLogger;
+
+    /**
+     * @param olmMachine - The rust-sdk's OlmMachine
+     * @param keyClaimManager - Our KeyClaimManager, which manages the queue of one-time-key claim requests
+     * @param room - The room we want to encrypt for
+     * @param encryptionSettings - body of the m.room.encryption event currently in force in this room
+     */
+    public constructor(
+        private readonly olmMachine: OlmMachine,
+        private readonly keyClaimManager: KeyClaimManager,
+        private readonly room: Room,
+        private encryptionSettings: IContent,
+    ) {
+        this.prefixedLogger = logger.withPrefix(`[${room.roomId} encryption]`);
+    }
+
+    /**
+     * Handle a new `m.room.encryption` event in this room
+     *
+     * @param config - The content of the encryption event
+     */
+    public onCryptoEvent(config: IContent): void {
+        if (JSON.stringify(this.encryptionSettings) != JSON.stringify(config)) {
+            this.prefixedLogger.error(`Ignoring m.room.encryption event which requests a change of config`);
+        }
+    }
+
+    /**
+     * Handle a new `m.room.member` event in this room
+     *
+     * @param member - new membership state
+     */
+    public onRoomMembership(member: RoomMember): void {
+        this.prefixedLogger.debug(`${member.membership} event for ${member.userId}`);
+
+        if (
+            member.membership == "join" ||
+            (member.membership == "invite" && this.room.shouldEncryptForInvitedMembers())
+        ) {
+            // make sure we are tracking the deviceList for this user
+            this.prefixedLogger.debug(`starting to track devices for: ${member.userId}`);
+            this.olmMachine.updateTrackedUsers([new UserId(member.userId)]);
+        }
+
+        // TODO: handle leaves (including our own)
+    }
+
+    /**
+     * Prepare to encrypt events in this room.
+     *
+     * This ensures that we have a megolm session ready to use and that we have shared its key with all the devices
+     * in the room.
+     */
+    public async ensureEncryptionSession(): Promise<void> {
+        if (this.encryptionSettings.algorithm !== "m.megolm.v1.aes-sha2") {
+            throw new Error(
+                `Cannot encrypt in ${this.room.roomId} for unsupported algorithm '${this.encryptionSettings.algorithm}'`,
+            );
+        }
+
+        const members = await this.room.getEncryptionTargetMembers();
+        this.prefixedLogger.debug(
+            `Encrypting for users (shouldEncryptForInvitedMembers: ${this.room.shouldEncryptForInvitedMembers()}):`,
+            members.map((u) => `${u.userId} (${u.membership})`),
+        );
+
+        const userList = members.map((u) => new UserId(u.userId));
+        await this.keyClaimManager.ensureSessionsForUsers(userList);
+
+        const rustEncryptionSettings = new EncryptionSettings();
+        /* FIXME historyVisibility, rotation, etc */
+
+        await this.olmMachine.shareRoomKey(new RoomId(this.room.roomId), userList, rustEncryptionSettings);
+    }
+
+    /**
+     * Encrypt an event for this room
+     *
+     * This will ensure that we have a megolm session for this room, share it with the devices in the room, and
+     * then encrypt the event using the session.
+     *
+     * @param event - Event to be encrypted.
+     */
+    public async encryptEvent(event: MatrixEvent): Promise<void> {
+        await this.ensureEncryptionSession();
+
+        const encryptedContent = await this.olmMachine.encryptRoomEvent(
+            new RoomId(this.room.roomId),
+            event.getType(),
+            JSON.stringify(event.getContent()),
+        );
+
+        event.makeEncrypted(
+            EventType.RoomMessageEncrypted,
+            JSON.parse(encryptedContent),
+            this.olmMachine.identityKeys.curve25519.toBase64(),
+            this.olmMachine.identityKeys.ed25519.toBase64(),
+        );
+    }
+}

src/rust-crypto/index.ts

@@ -18,7 +18,6 @@ import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-js";
 
 import { RustCrypto } from "./rust-crypto";
 import { logger } from "../logger";
-import { CryptoBackend } from "../common-crypto/CryptoBackend";
 import { RUST_SDK_STORE_PREFIX } from "./constants";
 import { IHttpOpts, MatrixHttpApi } from "../http-api";
 
@@ -26,7 +25,7 @@ export async function initRustCrypto(
     http: MatrixHttpApi<IHttpOpts & { onlyData: true }>,
     userId: string,
     deviceId: string,
-): Promise<CryptoBackend> {
+): Promise<RustCrypto> {
     // initialise the rust matrix-sdk-crypto-js, if it hasn't already been done
     await RustSdkCryptoJs.initAsync();
 

src/rust-crypto/rust-crypto.ts

@@ -15,29 +15,20 @@ limitations under the License.
 */
 
 import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-js";
-import {
-    KeysBackupRequest,
-    KeysClaimRequest,
-    KeysQueryRequest,
-    KeysUploadRequest,
-    SignatureUploadRequest,
-} from "@matrix-org/matrix-sdk-crypto-js";
 
 import type { IEventDecryptionResult, IMegolmSessionData } from "../@types/crypto";
 import type { IToDeviceEvent } from "../sync-accumulator";
+import type { IEncryptedEventInfo } from "../crypto/api";
 import { MatrixEvent } from "../models/event";
+import { Room } from "../models/room";
+import { RoomMember } from "../models/room-member";
 import { CryptoBackend, OnSyncCompletedData } from "../common-crypto/CryptoBackend";
 import { logger } from "../logger";
-import { IHttpOpts, MatrixHttpApi, Method } from "../http-api";
-import { QueryDict } from "../utils";
-
-/**
- * Common interface for all the request types returned by `OlmMachine.outgoingRequests`.
- */
-interface OutgoingRequest {
-    readonly id: string | undefined;
-    readonly type: number;
-}
+import { IHttpOpts, MatrixHttpApi } from "../http-api";
+import { DeviceTrustLevel, UserTrustLevel } from "../crypto/CrossSigning";
+import { RoomEncryptor } from "./RoomEncryptor";
+import { OutgoingRequest, OutgoingRequestProcessor } from "./OutgoingRequestProcessor";
+import { KeyClaimManager } from "./KeyClaimManager";
 
 /**
  * An implementation of {@link CryptoBackend} using the Rust matrix-sdk-crypto.
@@ -52,12 +43,27 @@ export class RustCrypto implements CryptoBackend {
     /** whether {@link outgoingRequestLoop} is currently running */
     private outgoingRequestLoopRunning = false;
 
+    /** mapping of roomId → encryptor class */
+    private roomEncryptors: Record<string, RoomEncryptor> = {};
+
+    private keyClaimManager: KeyClaimManager;
+    private outgoingRequestProcessor: OutgoingRequestProcessor;
+
     public constructor(
         private readonly olmMachine: RustSdkCryptoJs.OlmMachine,
-        private readonly http: MatrixHttpApi<IHttpOpts & { onlyData: true }>,
+        http: MatrixHttpApi<IHttpOpts & { onlyData: true }>,
         _userId: string,
         _deviceId: string,
-    ) {}
+    ) {
+        this.outgoingRequestProcessor = new OutgoingRequestProcessor(olmMachine, http);
+        this.keyClaimManager = new KeyClaimManager(olmMachine, this.outgoingRequestProcessor);
+    }
+
+    ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    //
+    // CryptoBackend implementation
+    //
+    ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
     public stop(): void {
         // stop() may be called multiple times, but attempting to close() the OlmMachine twice
@@ -67,15 +73,78 @@ export class RustCrypto implements CryptoBackend {
         }
         this.stopped = true;
 
+        this.keyClaimManager.stop();
+
         // make sure we close() the OlmMachine; doing so means that all the Rust objects will be
         // cleaned up; in particular, the indexeddb connections will be closed, which means they
         // can then be deleted.
         this.olmMachine.close();
     }
 
+    public prepareToEncrypt(room: Room): void {
+        const encryptor = this.roomEncryptors[room.roomId];
+
+        if (encryptor) {
+            encryptor.ensureEncryptionSession();
+        }
+    }
+
+    public async encryptEvent(event: MatrixEvent, _room: Room): Promise<void> {
+        const roomId = event.getRoomId()!;
+        const encryptor = this.roomEncryptors[roomId];
+
+        if (!encryptor) {
+            throw new Error(`Cannot encrypt event in unconfigured room ${roomId}`);
+        }
+
+        await encryptor.encryptEvent(event);
+    }
+
     public async decryptEvent(event: MatrixEvent): Promise<IEventDecryptionResult> {
-        await this.olmMachine.decryptRoomEvent("event", new RustSdkCryptoJs.RoomId("room"));
-        throw new Error("not implemented");
+        const roomId = event.getRoomId();
+        if (!roomId) {
+            // presumably, a to-device message. These are normally decrypted in preprocessToDeviceMessages
+            // so the fact it has come back here suggests that decryption failed.
+            //
+            // once we drop support for the libolm crypto implementation, we can stop passing to-device messages
+            // through decryptEvent and hence get rid of this case.
+            throw new Error("to-device event was not decrypted in preprocessToDeviceMessages");
+        }
+        const res = (await this.olmMachine.decryptRoomEvent(
+            JSON.stringify({
+                event_id: event.getId(),
+                type: event.getWireType(),
+                sender: event.getSender(),
+                state_key: event.getStateKey(),
+                content: event.getWireContent(),
+                origin_server_ts: event.getTs(),
+            }),
+            new RustSdkCryptoJs.RoomId(event.getRoomId()!),
+        )) as RustSdkCryptoJs.DecryptedRoomEvent;
+        return {
+            clearEvent: JSON.parse(res.event),
+            claimedEd25519Key: res.senderClaimedEd25519Key,
+            senderCurve25519Key: res.senderCurve25519Key,
+            forwardingCurve25519KeyChain: res.forwardingCurve25519KeyChain,
+        };
+    }
+
+    public getEventEncryptionInfo(event: MatrixEvent): IEncryptedEventInfo {
+        // TODO: make this work properly. Or better, replace it.
+
+        const ret: Partial<IEncryptedEventInfo> = {};
+
+        ret.senderKey = event.getSenderKey() ?? undefined;
+        ret.algorithm = event.getWireContent().algorithm;
+
+        if (!ret.senderKey || !ret.algorithm) {
+            ret.encrypted = false;
+            return ret as IEncryptedEventInfo;
+        }
+        ret.encrypted = true;
+        ret.authenticated = true;
+        ret.mismatchedSender = true;
+        return ret as IEncryptedEventInfo;
     }
 
     public async userHasCrossSigningKeys(): Promise<boolean> {
@@ -88,6 +157,16 @@ export class RustCrypto implements CryptoBackend {
         return [];
     }
 
+    public checkUserTrust(userId: string): UserTrustLevel {
+        // TODO
+        return new UserTrustLevel(false, false, false);
+    }
+
+    public checkDeviceTrust(userId: string, deviceId: string): DeviceTrustLevel {
+        // TODO
+        return new DeviceTrustLevel(false, false, false, false);
+    }
+
     ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     //
     // SyncCryptoCallbacks implementation
@@ -113,6 +192,30 @@ export class RustCrypto implements CryptoBackend {
         return JSON.parse(result);
     }
 
+    /** called by the sync loop on m.room.encrypted events
+     *
+     * @param room - in which the event was received
+     * @param event - encryption event to be processed
+     */
+    public async onCryptoEvent(room: Room, event: MatrixEvent): Promise<void> {
+        const config = event.getContent();
+
+        const existingEncryptor = this.roomEncryptors[room.roomId];
+        if (existingEncryptor) {
+            existingEncryptor.onCryptoEvent(config);
+        } else {
+            this.roomEncryptors[room.roomId] = new RoomEncryptor(this.olmMachine, this.keyClaimManager, room, config);
+        }
+
+        // start tracking devices for any users already known to be in this room.
+        const members = await room.getEncryptionTargetMembers();
+        logger.debug(
+            `[${room.roomId} encryption] starting to track devices for: `,
+            members.map((u) => `${u.userId} (${u.membership})`),
+        );
+        await this.olmMachine.updateTrackedUsers(members.map((u) => new RustSdkCryptoJs.UserId(u.userId)));
+    }
+
     /** called by the sync loop after processing each sync.
      *
      * TODO: figure out something equivalent for sliding sync.
@@ -125,6 +228,27 @@ export class RustCrypto implements CryptoBackend {
         this.outgoingRequestLoop();
     }
 
+    ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    //
+    // Other public functions
+    //
+    ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+
+    /** called by the MatrixClient on a room membership event
+     *
+     * @param event - The matrix event which caused this event to fire.
+     * @param member - The member whose RoomMember.membership changed.
+     * @param oldMembership - The previous membership state. Null if it's a new member.
+     */
+    public onRoomMembership(event: MatrixEvent, member: RoomMember, oldMembership?: string): void {
+        const enc = this.roomEncryptors[event.getRoomId()!];
+        if (!enc) {
+            // not encrypting in this room
+            return;
+        }
+        enc.onRoomMembership(member);
+    }
+
     ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     //
     // Outgoing requests
@@ -144,7 +268,7 @@ export class RustCrypto implements CryptoBackend {
                     return;
                 }
                 for (const msg of outgoingRequests) {
-                    await this.doOutgoingRequest(msg as OutgoingRequest);
+                    await this.outgoingRequestProcessor.makeOutgoingRequest(msg as OutgoingRequest);
                 }
             }
         } catch (e) {
@@ -153,49 +277,4 @@ export class RustCrypto implements CryptoBackend {
             this.outgoingRequestLoopRunning = false;
         }
     }
-
-    private async doOutgoingRequest(msg: OutgoingRequest): Promise<void> {
-        let resp: string;
-
-        /* refer https://docs.rs/matrix-sdk-crypto/0.6.0/matrix_sdk_crypto/requests/enum.OutgoingRequests.html
-         * for the complete list of request types
-         */
-        if (msg instanceof KeysUploadRequest) {
-            resp = await this.rawJsonRequest(Method.Post, "/_matrix/client/v3/keys/upload", {}, msg.body);
-        } else if (msg instanceof KeysQueryRequest) {
-            resp = await this.rawJsonRequest(Method.Post, "/_matrix/client/v3/keys/query", {}, msg.body);
-        } else if (msg instanceof KeysClaimRequest) {
-            resp = await this.rawJsonRequest(Method.Post, "/_matrix/client/v3/keys/claim", {}, msg.body);
-        } else if (msg instanceof SignatureUploadRequest) {
-            resp = await this.rawJsonRequest(Method.Post, "/_matrix/client/v3/keys/signatures/upload", {}, msg.body);
-        } else if (msg instanceof KeysBackupRequest) {
-            resp = await this.rawJsonRequest(Method.Put, "/_matrix/client/v3/room_keys/keys", {}, msg.body);
-        } else {
-            // TODO: ToDeviceRequest, RoomMessageRequest
-            logger.warn("Unsupported outgoing message", Object.getPrototypeOf(msg));
-            resp = "";
-        }
-
-        if (msg.id) {
-            await this.olmMachine.markRequestAsSent(msg.id, msg.type, resp);
-        }
-    }
-
-    private async rawJsonRequest(method: Method, path: string, queryParams: QueryDict, body: string): Promise<string> {
-        const opts = {
-            // inhibit the JSON stringification and parsing within HttpApi.
-            json: false,
-
-            // nevertheless, we are sending, and accept, JSON.
-            headers: {
-                "Content-Type": "application/json",
-                "Accept": "application/json",
-            },
-
-            // we use the full prefix
-            prefix: "",
-        };
-
-        return await this.http.authedRequest<string>(method, path, queryParams, body, opts);
-    }
 }

src/sliding-sync-sdk.ts

@@ -736,8 +736,8 @@ export class SlidingSyncSdk {
 
         const processRoomEvent = async (e: MatrixEvent): Promise<void> => {
             client.emit(ClientEvent.Event, e);
-            if (e.isState() && e.getType() == EventType.RoomEncryption && this.syncOpts.crypto) {
-                await this.syncOpts.crypto.onCryptoEvent(room, e);
+            if (e.isState() && e.getType() == EventType.RoomEncryption && this.syncOpts.cryptoCallbacks) {
+                await this.syncOpts.cryptoCallbacks.onCryptoEvent(room, e);
             }
         };
 

src/sliding-sync.ts

@@ -70,7 +70,7 @@ export interface MSC3575List extends MSC3575RoomSubscription {
  */
 export interface MSC3575SlidingSyncRequest {
     // json body params
-    lists?: MSC3575List[];
+    lists?: Record<string, MSC3575List>;
     unsubscribe_rooms?: string[];
     room_subscriptions?: Record<string, MSC3575RoomSubscription>;
     extensions?: object;
@@ -137,7 +137,7 @@ type Operation = DeleteOperation | InsertOperation | InvalidateOperation | SyncO
 export interface MSC3575SlidingSyncResponse {
     pos: string;
     txn_id?: string;
-    lists: ListResponse[];
+    lists: Record<string, ListResponse>;
     rooms: Record<string, MSC3575RoomData>;
     extensions: Record<string, object>;
 }
@@ -332,11 +332,7 @@ export type SlidingSyncEventHandlerMap = {
         resp: MSC3575SlidingSyncResponse | null,
         err?: Error,
     ) => void;
-    [SlidingSyncEvent.List]: (
-        listIndex: number,
-        joinedCount: number,
-        roomIndexToRoomId: Record<number, string>,
-    ) => void;
+    [SlidingSyncEvent.List]: (listKey: string, joinedCount: number, roomIndexToRoomId: Record<number, string>) => void;
 };
 
 /**
@@ -346,7 +342,7 @@ export type SlidingSyncEventHandlerMap = {
  * To hook this up with the JS SDK, you need to use SlidingSyncSdk.
  */
 export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSyncEventHandlerMap> {
-    private lists: SlidingList[];
+    private lists: Map<string, SlidingList>;
     private listModifiedCount = 0;
     private terminated = false;
     // flag set when resend() is called because we cannot rely on detecting AbortError in JS SDK :(
@@ -380,13 +376,16 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
      */
     public constructor(
         private readonly proxyBaseUrl: string,
-        lists: MSC3575List[],
+        lists: Map<string, MSC3575List>,
         private roomSubscriptionInfo: MSC3575RoomSubscription,
         private readonly client: MatrixClient,
         private readonly timeoutMS: number,
     ) {
         super();
-        this.lists = lists.map((l) => new SlidingList(l));
+        this.lists = new Map<string, SlidingList>();
+        lists.forEach((list, key) => {
+            this.lists.set(key, new SlidingList(list));
+        });
     }
 
     /**
@@ -423,70 +422,70 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
     }
 
     /**
-     * Get the length of the sliding lists.
-     * @returns The number of lists in the sync request
-     */
-    public listLength(): number {
-        return this.lists.length;
-    }
-
-    /**
-     * Get the room data for a list.
-     * @param index - The list index
+     * Get the room index data for a list.
+     * @param key - The list key
      * @returns The list data which contains the rooms in this list
      */
-    public getListData(index: number): { joinedCount: number; roomIndexToRoomId: Record<number, string> } | null {
-        if (!this.lists[index]) {
+    public getListData(key: string): { joinedCount: number; roomIndexToRoomId: Record<number, string> } | null {
+        const data = this.lists.get(key);
+        if (!data) {
             return null;
         }
         return {
-            joinedCount: this.lists[index].joinedCount,
-            roomIndexToRoomId: Object.assign({}, this.lists[index].roomIndexToRoomId),
+            joinedCount: data.joinedCount,
+            roomIndexToRoomId: Object.assign({}, data.roomIndexToRoomId),
         };
     }
 
     /**
-     * Get the full list parameters for a list index. This function is provided for callers to use
+     * Get the full request list parameters for a list index. This function is provided for callers to use
      * in conjunction with setList to update fields on an existing list.
-     * @param index - The list index to get the list for.
-     * @returns A copy of the list or undefined.
+     * @param key - The list key to get the params for.
+     * @returns A copy of the list params or undefined.
      */
-    public getList(index: number): MSC3575List | null {
-        if (!this.lists[index]) {
+    public getListParams(key: string): MSC3575List | null {
+        const params = this.lists.get(key);
+        if (!params) {
             return null;
         }
-        return this.lists[index].getList(true);
+        return params.getList(true);
     }
 
     /**
      * Set new ranges for an existing list. Calling this function when _only_ the ranges have changed
      * is more efficient than calling setList(index,list) as this function won't resend sticky params,
      * whereas setList always will.
-     * @param index - The list index to modify
+     * @param key - The list key to modify
      * @param ranges - The new ranges to apply.
      * @returns A promise which resolves to the transaction ID when it has been received down sync
      * (or rejects with the transaction ID if the action was not applied e.g the request was cancelled
      * immediately after sending, in which case the action will be applied in the subsequent request)
      */
-    public setListRanges(index: number, ranges: number[][]): Promise<string> {
-        this.lists[index].updateListRange(ranges);
+    public setListRanges(key: string, ranges: number[][]): Promise<string> {
+        const list = this.lists.get(key);
+        if (!list) {
+            return Promise.reject(new Error("no list with key " + key));
+        }
+        list.updateListRange(ranges);
         return this.resend();
     }
 
     /**
      * Add or replace a list. Calling this function will interrupt the /sync request to resend new
      * lists.
-     * @param index - The index to modify
+     * @param key - The key to modify
      * @param list - The new list parameters.
      * @returns A promise which resolves to the transaction ID when it has been received down sync
      * (or rejects with the transaction ID if the action was not applied e.g the request was cancelled
      * immediately after sending, in which case the action will be applied in the subsequent request)
      */
-    public setList(index: number, list: MSC3575List): Promise<string> {
-        if (this.lists[index]) {
-            this.lists[index].replaceList(list);
+    public setList(key: string, list: MSC3575List): Promise<string> {
+        const existingList = this.lists.get(key);
+        if (existingList) {
+            existingList.replaceList(list);
+            this.lists.set(key, existingList);
         } else {
-            this.lists[index] = new SlidingList(list);
+            this.lists.set(key, new SlidingList(list));
         }
         this.listModifiedCount += 1;
         return this.resend();
@@ -592,32 +591,44 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
         this.emit(SlidingSyncEvent.Lifecycle, state, resp, err);
     }
 
-    private shiftRight(listIndex: number, hi: number, low: number): void {
+    private shiftRight(listKey: string, hi: number, low: number): void {
+        const list = this.lists.get(listKey);
+        if (!list) {
+            return;
+        }
         //     l   h
         // 0,1,2,3,4 <- before
         // 0,1,2,2,3 <- after, hi is deleted and low is duplicated
         for (let i = hi; i > low; i--) {
-            if (this.lists[listIndex].isIndexInRange(i)) {
-                this.lists[listIndex].roomIndexToRoomId[i] = this.lists[listIndex].roomIndexToRoomId[i - 1];
+            if (list.isIndexInRange(i)) {
+                list.roomIndexToRoomId[i] = list.roomIndexToRoomId[i - 1];
             }
         }
     }
 
-    private shiftLeft(listIndex: number, hi: number, low: number): void {
+    private shiftLeft(listKey: string, hi: number, low: number): void {
+        const list = this.lists.get(listKey);
+        if (!list) {
+            return;
+        }
         //     l   h
         // 0,1,2,3,4 <- before
         // 0,1,3,4,4 <- after, low is deleted and hi is duplicated
         for (let i = low; i < hi; i++) {
-            if (this.lists[listIndex].isIndexInRange(i)) {
-                this.lists[listIndex].roomIndexToRoomId[i] = this.lists[listIndex].roomIndexToRoomId[i + 1];
+            if (list.isIndexInRange(i)) {
+                list.roomIndexToRoomId[i] = list.roomIndexToRoomId[i + 1];
             }
         }
     }
 
-    private removeEntry(listIndex: number, index: number): void {
+    private removeEntry(listKey: string, index: number): void {
+        const list = this.lists.get(listKey);
+        if (!list) {
+            return;
+        }
         // work out the max index
         let max = -1;
-        for (const n in this.lists[listIndex].roomIndexToRoomId) {
+        for (const n in list.roomIndexToRoomId) {
             if (Number(n) > max) {
                 max = Number(n);
             }
@@ -626,14 +637,18 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
             return;
         }
         // Everything higher than the gap needs to be shifted left.
-        this.shiftLeft(listIndex, max, index);
-        delete this.lists[listIndex].roomIndexToRoomId[max];
+        this.shiftLeft(listKey, max, index);
+        delete list.roomIndexToRoomId[max];
     }
 
-    private addEntry(listIndex: number, index: number): void {
+    private addEntry(listKey: string, index: number): void {
+        const list = this.lists.get(listKey);
+        if (!list) {
+            return;
+        }
         // work out the max index
         let max = -1;
-        for (const n in this.lists[listIndex].roomIndexToRoomId) {
+        for (const n in list.roomIndexToRoomId) {
             if (Number(n) > max) {
                 max = Number(n);
             }
@@ -642,30 +657,37 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
             return;
         }
         // Everything higher than the gap needs to be shifted right, +1 so we don't delete the highest element
-        this.shiftRight(listIndex, max + 1, index);
+        this.shiftRight(listKey, max + 1, index);
     }
 
-    private processListOps(list: ListResponse, listIndex: number): void {
+    private processListOps(list: ListResponse, listKey: string): void {
         let gapIndex = -1;
+        const listData = this.lists.get(listKey);
+        if (!listData) {
+            return;
+        }
         list.ops.forEach((op: Operation) => {
+            if (!listData) {
+                return;
+            }
             switch (op.op) {
                 case "DELETE": {
-                    logger.debug("DELETE", listIndex, op.index, ";");
-                    delete this.lists[listIndex].roomIndexToRoomId[op.index];
+                    logger.debug("DELETE", listKey, op.index, ";");
+                    delete listData.roomIndexToRoomId[op.index];
                     if (gapIndex !== -1) {
                         // we already have a DELETE operation to process, so process it.
-                        this.removeEntry(listIndex, gapIndex);
+                        this.removeEntry(listKey, gapIndex);
                     }
                     gapIndex = op.index;
                     break;
                 }
                 case "INSERT": {
-                    logger.debug("INSERT", listIndex, op.index, op.room_id, ";");
-                    if (this.lists[listIndex].roomIndexToRoomId[op.index]) {
+                    logger.debug("INSERT", listKey, op.index, op.room_id, ";");
+                    if (listData.roomIndexToRoomId[op.index]) {
                         // something is in this space, shift items out of the way
                         if (gapIndex < 0) {
                             // we haven't been told where to shift from, so make way for a new room entry.
-                            this.addEntry(listIndex, op.index);
+                            this.addEntry(listKey, op.index);
                         } else if (gapIndex > op.index) {
                             // the gap is further down the list, shift every element to the right
                             // starting at the gap so we can just shift each element in turn:
@@ -674,11 +696,11 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
                             // [A,B,B,C] i=2
                             // [A,A,B,C] i=1
                             // Terminate. We'll assign into op.index next.
-                            this.shiftRight(listIndex, gapIndex, op.index);
+                            this.shiftRight(listKey, gapIndex, op.index);
                         } else if (gapIndex < op.index) {
                             // the gap is further up the list, shift every element to the left
                             // starting at the gap so we can just shift each element in turn
-                            this.shiftLeft(listIndex, op.index, gapIndex);
+                            this.shiftLeft(listKey, op.index, gapIndex);
                         }
                     }
                     // forget the gap, we don't need it anymore. This is outside the check for
@@ -686,15 +708,15 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
                     // forget the gap, not conditionally based on the presence of a room in the INSERT
                     // position. Without this, DELETE 0; INSERT 0; would do the wrong thing.
                     gapIndex = -1;
-                    this.lists[listIndex].roomIndexToRoomId[op.index] = op.room_id;
+                    listData.roomIndexToRoomId[op.index] = op.room_id;
                     break;
                 }
                 case "INVALIDATE": {
                     const startIndex = op.range[0];
                     for (let i = startIndex; i <= op.range[1]; i++) {
-                        delete this.lists[listIndex].roomIndexToRoomId[i];
+                        delete listData.roomIndexToRoomId[i];
                     }
-                    logger.debug("INVALIDATE", listIndex, op.range[0], op.range[1], ";");
+                    logger.debug("INVALIDATE", listKey, op.range[0], op.range[1], ";");
                     break;
                 }
                 case "SYNC": {
@@ -704,9 +726,9 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
                         if (!roomId) {
                             break; // we are at the end of list
                         }
-                        this.lists[listIndex].roomIndexToRoomId[i] = roomId;
+                        listData.roomIndexToRoomId[i] = roomId;
                     }
-                    logger.debug("SYNC", listIndex, op.range[0], op.range[1], (op.room_ids || []).join(" "), ";");
+                    logger.debug("SYNC", listKey, op.range[0], op.range[1], (op.room_ids || []).join(" "), ";");
                     break;
                 }
             }
@@ -714,7 +736,7 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
         if (gapIndex !== -1) {
             // we already have a DELETE operation to process, so process it
             // Everything higher than the gap needs to be shifted left.
-            this.removeEntry(listIndex, gapIndex);
+            this.removeEntry(listKey, gapIndex);
         }
     }
 
@@ -814,10 +836,12 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
             let resp: MSC3575SlidingSyncResponse | undefined;
             try {
                 const listModifiedCount = this.listModifiedCount;
+                const reqLists: Record<string, MSC3575List> = {};
+                this.lists.forEach((l: SlidingList, key: string) => {
+                    reqLists[key] = l.getList(false);
+                });
                 const reqBody: MSC3575SlidingSyncRequest = {
-                    lists: this.lists.map((l) => {
-                        return l.getList(false);
-                    }),
+                    lists: reqLists,
                     pos: currentPos,
                     timeout: this.timeoutMS,
                     clientTimeout: this.timeoutMS + BUFFER_PERIOD_MS,
@@ -866,11 +890,15 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
                     l.setModified(false);
                 });
                 // set default empty values so we don't need to null check
-                resp.lists = resp.lists || [];
+                resp.lists = resp.lists || {};
                 resp.rooms = resp.rooms || {};
                 resp.extensions = resp.extensions || {};
-                resp.lists.forEach((val, i) => {
-                    this.lists[i].joinedCount = val.count;
+                Object.keys(resp.lists).forEach((key: string) => {
+                    const list = this.lists.get(key);
+                    if (!list || !resp) {
+                        return;
+                    }
+                    list.joinedCount = resp.lists[key].count;
                 });
                 this.invokeLifecycleListeners(SlidingSyncState.RequestFinished, resp);
             } catch (err) {
@@ -899,25 +927,24 @@ export class SlidingSync extends TypedEventEmitter<SlidingSyncEvent, SlidingSync
                 this.invokeRoomDataListeners(roomId, resp!.rooms[roomId]);
             });
 
-            const listIndexesWithUpdates: Set<number> = new Set();
+            const listKeysWithUpdates: Set<string> = new Set();
             if (!doNotUpdateList) {
-                resp.lists.forEach((list, listIndex) => {
+                for (const [key, list] of Object.entries(resp.lists)) {
                     list.ops = list.ops || [];
                     if (list.ops.length > 0) {
-                        listIndexesWithUpdates.add(listIndex);
+                        listKeysWithUpdates.add(key);
                     }
-                    this.processListOps(list, listIndex);
-                });
+                    this.processListOps(list, key);
+                }
             }
             this.invokeLifecycleListeners(SlidingSyncState.Complete, resp);
             this.onPostExtensionsResponse(resp.extensions);
-            listIndexesWithUpdates.forEach((i) => {
-                this.emit(
-                    SlidingSyncEvent.List,
-                    i,
-                    this.lists[i].joinedCount,
-                    Object.assign({}, this.lists[i].roomIndexToRoomId),
-                );
+            listKeysWithUpdates.forEach((listKey: string) => {
+                const list = this.lists.get(listKey);
+                if (!list) {
+                    return;
+                }
+                this.emit(SlidingSyncEvent.List, listKey, list.joinedCount, Object.assign({}, list.roomIndexToRoomId));
             });
 
             this.resolveTransactionDefers(resp.txn_id);

src/sync.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2015 - 2022 The Matrix.org Foundation C.I.C.
+Copyright 2015 - 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -198,7 +198,7 @@ export function defaultClientOpts(opts?: IStoredClientOpts): IStoredClientOpts {
         resolveInvitesToProfiles: false,
         pollTimeout: 30 * 1000,
         pendingEventOrdering: PendingEventOrdering.Chronological,
-        experimentalThreadSupport: false,
+        threadSupport: false,
         ...opts,
     };
 }
@@ -1254,11 +1254,12 @@ export class SyncApi {
 
             const inviter = room.currentState.getStateEvents(EventType.RoomMember, client.getUserId()!)?.getSender();
 
-            if (client.isCryptoEnabled()) {
-                const parkedHistory = await client.crypto!.cryptoStore.takeParkedSharedHistory(room.roomId);
+            const crypto = client.crypto;
+            if (crypto) {
+                const parkedHistory = await crypto.cryptoStore.takeParkedSharedHistory(room.roomId);
                 for (const parked of parkedHistory) {
                     if (parked.senderId === inviter) {
-                        await client.crypto!.olmDevice.addInboundGroupSession(
+                        await crypto.olmDevice.addInboundGroupSession(
                             room.roomId,
                             parked.senderKey,
                             parked.forwardingCurve25519KeyChain,
@@ -1408,10 +1409,10 @@ export class SyncApi {
             // avoids a race condition if the application tries to send a message after the
             // state event is processed, but before crypto is enabled, which then causes the
             // crypto layer to complain.
-            if (this.syncOpts.crypto) {
+            if (this.syncOpts.cryptoCallbacks) {
                 for (const e of stateEvents.concat(events)) {
                     if (e.isState() && e.getType() === EventType.RoomEncryption && e.getStateKey() === "") {
-                        await this.syncOpts.crypto.onCryptoEvent(room, e);
+                        await this.syncOpts.cryptoCallbacks.onCryptoEvent(room, e);
                     }
                 }
             }

src/utils.ts

@@ -1,6 +1,5 @@
 /*
-Copyright 2015, 2016 OpenMarket Ltd
-Copyright 2019 The Matrix.org Foundation C.I.C.
+Copyright 2015, 2016, 2019, 2023 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -392,13 +391,22 @@ export function ensureNoTrailingSlash(url?: string): string | undefined {
     }
 }
 
-// Returns a promise which resolves with a given value after the given number of ms
+/**
+ * Returns a promise which resolves with a given value after the given number of ms
+ */
 export function sleep<T>(ms: number, value?: T): Promise<T> {
     return new Promise((resolve) => {
         setTimeout(resolve, ms, value);
     });
 }
 
+/**
+ * Promise/async version of {@link setImmediate}.
+ */
+export function immediate(): Promise<void> {
+    return new Promise(setImmediate);
+}
+
 export function isNullOrUndefined(val: any): boolean {
     return val === null || val === undefined;
 }

src/webrtc/call.ts

@@ -236,7 +236,7 @@ export enum CallErrorCode {
     /**
      * We transferred the call off to somewhere else
      */
-    Transfered = "transferred",
+    Transferred = "transferred",
 
     /**
      * A call from the same user was found with a new session id
@@ -387,6 +387,10 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
     private opponentSessionId?: string;
     public groupCallId?: string;
 
+    // Used to keep the timer for the delay before actually stopping our
+    // video track after muting (see setLocalVideoMuted)
+    private stopVideoTrackTimer?: ReturnType<typeof setTimeout>;
+
     /**
      * Construct a new Matrix Call.
      * @param opts - Config options.
@@ -480,7 +484,9 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
     }
 
     public get type(): CallType {
-        return this.hasLocalUserMediaVideoTrack || this.hasRemoteUserMediaVideoTrack ? CallType.Video : CallType.Voice;
+        // we may want to look for a video receiver here rather than a track to match the
+        // sender behaviour, although in practice they should be the same thing
+        return this.hasUserMediaVideoSender || this.hasRemoteUserMediaVideoTrack ? CallType.Video : CallType.Voice;
     }
 
     public get hasLocalUserMediaVideoTrack(): boolean {
@@ -503,6 +509,14 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
         });
     }
 
+    private get hasUserMediaAudioSender(): boolean {
+        return Boolean(this.transceivers.get(getTransceiverKey(SDPStreamMetadataPurpose.Usermedia, "audio"))?.sender);
+    }
+
+    private get hasUserMediaVideoSender(): boolean {
+        return Boolean(this.transceivers.get(getTransceiverKey(SDPStreamMetadataPurpose.Usermedia, "video"))?.sender);
+    }
+
     public get localUsermediaFeed(): CallFeed | undefined {
         return this.getLocalFeeds().find((feed) => feed.purpose === SDPStreamMetadataPurpose.Usermedia);
     }
@@ -786,9 +800,9 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
                     const newSender = this.peerConn!.addTrack(track, callFeed.stream);
 
                     // now go & fish for the new transceiver
-                    const newTransciever = this.peerConn!.getTransceivers().find((t) => t.sender === newSender);
-                    if (newTransciever) {
-                        this.transceivers.set(tKey, newTransciever);
+                    const newTransceiver = this.peerConn!.getTransceivers().find((t) => t.sender === newSender);
+                    if (newTransceiver) {
+                        this.transceivers.set(tKey, newTransceiver);
                     } else {
                         logger.warn("Didn't find a matching transceiver after adding track!");
                     }
@@ -1292,18 +1306,7 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
             this.localUsermediaStream!.addTrack(track);
         }
 
-        // Secondly, we remove tracks that we no longer need from the peer
-        // connection, if any. This only happens when we mute the video atm.
-        // This will change the transceiver direction to "inactive" and
-        // therefore cause re-negotiation.
-        for (const kind of ["audio", "video"]) {
-            const sender = this.transceivers.get(getTransceiverKey(SDPStreamMetadataPurpose.Usermedia, kind))?.sender;
-            // Only remove the track if we aren't going to immediately replace it
-            if (sender && !stream.getTracks().find((t) => t.kind === kind)) {
-                this.peerConn?.removeTrack(sender);
-            }
-        }
-        // Thirdly, we replace the old tracks, if possible.
+        // Then replace the old tracks, if possible.
         for (const track of stream.getTracks()) {
             const tKey = getTransceiverKey(SDPStreamMetadataPurpose.Usermedia, track.kind);
 
@@ -1344,9 +1347,9 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
                 );
 
                 const newSender = this.peerConn!.addTrack(track, this.localUsermediaStream!);
-                const newTransciever = this.peerConn!.getTransceivers().find((t) => t.sender === newSender);
-                if (newTransciever) {
-                    this.transceivers.set(tKey, newTransciever);
+                const newTransceiver = this.peerConn!.getTransceivers().find((t) => t.sender === newSender);
+                if (newTransceiver) {
+                    this.transceivers.set(tKey, newTransceiver);
                 } else {
                     logger.warn("Couldn't find matching transceiver for newly added track!");
                 }
@@ -1361,22 +1364,51 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
      */
     public async setLocalVideoMuted(muted: boolean): Promise<boolean> {
         logger.log(`call ${this.callId} setLocalVideoMuted ${muted}`);
+
+        // if we were still thinking about stopping and removing the video
+        // track: don't, because we want it back.
+        if (!muted && this.stopVideoTrackTimer !== undefined) {
+            clearTimeout(this.stopVideoTrackTimer);
+            this.stopVideoTrackTimer = undefined;
+        }
+
         if (!(await this.client.getMediaHandler().hasVideoDevice())) {
             return this.isLocalVideoMuted();
         }
 
-        if (!this.hasLocalUserMediaVideoTrack && !muted) {
+        if (!this.hasUserMediaVideoSender && !muted) {
             await this.upgradeCall(false, true);
             return this.isLocalVideoMuted();
         }
-        if (this.opponentSupportsSDPStreamMetadata()) {
-            const stream = await this.client.getMediaHandler().getUserMediaStream(true, !muted);
+
+        // we may not have a video track - if not, re-request usermedia
+        if (!muted && this.localUsermediaStream!.getVideoTracks().length === 0) {
+            const stream = await this.client.getMediaHandler().getUserMediaStream(true, true);
             await this.updateLocalUsermediaStream(stream);
-        } else {
-            this.localUsermediaFeed?.setAudioVideoMuted(null, muted);
         }
+
+        this.localUsermediaFeed?.setAudioVideoMuted(null, muted);
+
         this.updateMuteStatus();
         await this.sendMetadataUpdate();
+
+        // if we're muting video, set a timeout to stop & remove the video track so we release
+        // the camera. We wait a short time to do this because when we disable a track, WebRTC
+        // will send black video for it. If we just stop and remove it straight away, the video
+        // will just freeze which means that when we unmute video, the other side will briefly
+        // get a static frame of us from before we muted. This way, the still frame is just black.
+        // A very small delay is not always enough so the theory here is that it needs to be long
+        // enough for WebRTC to encode a frame: 120ms should be long enough even if we're only
+        // doing 10fps.
+        if (muted) {
+            this.stopVideoTrackTimer = setTimeout(() => {
+                for (const t of this.localUsermediaStream!.getVideoTracks()) {
+                    t.stop();
+                    this.localUsermediaStream!.removeTrack(t);
+                }
+            }, 120);
+        }
+
         return this.isLocalVideoMuted();
     }
 
@@ -1404,7 +1436,7 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
             return this.isMicrophoneMuted();
         }
 
-        if (!this.hasLocalUserMediaAudioTrack && !muted) {
+        if (!muted && (!this.hasUserMediaAudioSender || !this.hasLocalUserMediaAudioTrack)) {
             await this.upgradeCall(true, false);
             return this.isMicrophoneMuted();
         }
@@ -1496,6 +1528,7 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
                 this.localUsermediaStream!.id
             } micShouldBeMuted ${micShouldBeMuted} vidShouldBeMuted ${vidShouldBeMuted}`,
         );
+
         setTracksEnabled(this.localUsermediaStream!.getAudioTracks(), !micShouldBeMuted);
         setTracksEnabled(this.localUsermediaStream!.getVideoTracks(), !vidShouldBeMuted);
     }
@@ -1610,25 +1643,25 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
                     continue;
                 }
 
-                const extraconfig: string[] = [];
+                const extraConfig: string[] = [];
                 if (mod.enableDtx !== undefined) {
-                    extraconfig.push(`usedtx=${mod.enableDtx ? "1" : "0"}`);
+                    extraConfig.push(`usedtx=${mod.enableDtx ? "1" : "0"}`);
                 }
                 if (mod.maxAverageBitrate !== undefined) {
-                    extraconfig.push(`maxaveragebitrate=${mod.maxAverageBitrate}`);
+                    extraConfig.push(`maxaveragebitrate=${mod.maxAverageBitrate}`);
                 }
 
                 let found = false;
                 for (const fmtp of media.fmtp) {
                     if (payloadTypeToCodecMap.get(fmtp.payload) === mod.codec) {
                         found = true;
-                        fmtp.config += ";" + extraconfig.join(";");
+                        fmtp.config += ";" + extraConfig.join(";");
                     }
                 }
                 if (!found) {
                     media.fmtp.push({
                         payload: codecToPayloadTypeMap.get(mod.codec)!,
-                        config: extraconfig.join(";"),
+                        config: extraConfig.join(";"),
                     });
                 }
             }
@@ -2302,11 +2335,16 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
 
             const userId = this.invitee || this.getOpponentMember()!.userId;
             if (this.client.getUseE2eForGroupCall()) {
+                if (!this.opponentDeviceInfo) {
+                    logger.warn(`Call ${this.callId} sendVoipEvent() failed: we do not have opponentDeviceInfo`);
+                    return;
+                }
+
                 await this.client.encryptAndSendToDevices(
                     [
                         {
                             userId,
-                            deviceInfo: this.opponentDeviceInfo!,
+                            deviceInfo: this.opponentDeviceInfo,
                         },
                     ],
                     {
@@ -2417,7 +2455,7 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
 
         await this.sendVoipEvent(EventType.CallReplaces, body);
 
-        await this.terminate(CallParty.Local, CallErrorCode.Transfered, true);
+        await this.terminate(CallParty.Local, CallErrorCode.Transferred, true);
     }
 
     /*
@@ -2458,8 +2496,8 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
 
         await this.sendVoipEvent(EventType.CallReplaces, bodyToTransferee);
 
-        await this.terminate(CallParty.Local, CallErrorCode.Transfered, true);
-        await transferTargetCall.terminate(CallParty.Local, CallErrorCode.Transfered, true);
+        await this.terminate(CallParty.Local, CallErrorCode.Transferred, true);
+        await transferTargetCall.terminate(CallParty.Local, CallErrorCode.Transferred, true);
     }
 
     private async terminate(hangupParty: CallParty, hangupReason: CallErrorCode, shouldEmit: boolean): Promise<void> {
@@ -2477,6 +2515,10 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
             clearInterval(this.callLengthInterval);
             this.callLengthInterval = undefined;
         }
+        if (this.stopVideoTrackTimer !== undefined) {
+            clearTimeout(this.stopVideoTrackTimer);
+            this.stopVideoTrackTimer = undefined;
+        }
 
         for (const [stream, listener] of this.removeTrackListeners) {
             stream.removeEventListener("removetrack", listener);
@@ -2504,7 +2546,7 @@ export class MatrixCall extends TypedEventEmitter<CallEvent, CallEventHandlerMap
 
         for (const feed of this.feeds) {
             // Slightly awkward as local feed need to go via the correct method on
-            // the mediahandler so they get removed from mediahandler (remote tracks
+            // the MediaHandler so they get removed from MediaHandler (remote tracks
             // don't)
             // NB. We clone local streams when passing them to individual calls in a group
             // call, so we can (and should) stop the clones once we no longer need them:

src/webrtc/callFeed.ts

@@ -223,7 +223,7 @@ export class CallFeed extends TypedEventEmitter<CallFeedEvent, EventHandlerMap>
 
     /**
      * Replaces the current MediaStream with a new one.
-     * The stream will be different and new stream as remore parties are
+     * The stream will be different and new stream as remote parties are
      * concerned, but this can be used for convenience locally to set up
      * volume listeners automatically on the new stream etc.
      * @param newStream - new stream with which to replace the current one

src/webrtc/groupCall.ts

@@ -208,6 +208,7 @@ export class GroupCall extends TypedEventEmitter<
     private resendMemberStateTimer: ReturnType<typeof setInterval> | null = null;
     private initWithAudioMuted = false;
     private initWithVideoMuted = false;
+    private initCallFeedPromise?: Promise<void>;
 
     public constructor(
         private client: MatrixClient,
@@ -347,36 +348,43 @@ export class GroupCall extends TypedEventEmitter<
         );
     }
 
-    public async initLocalCallFeed(): Promise<CallFeed> {
-        logger.log(`groupCall ${this.groupCallId} initLocalCallFeed`);
-
+    public async initLocalCallFeed(): Promise<void> {
         if (this.state !== GroupCallState.LocalCallFeedUninitialized) {
             throw new Error(`Cannot initialize local call feed in the "${this.state}" state.`);
         }
-
         this.state = GroupCallState.InitializingLocalCallFeed;
 
-        let stream: MediaStream;
+        // wraps the real method to serialise calls, because we don't want to try starting
+        // multiple call feeds at once
+        if (this.initCallFeedPromise) return this.initCallFeedPromise;
 
-        let disposed = false;
-        const onState = (state: GroupCallState): void => {
-            if (state === GroupCallState.LocalCallFeedUninitialized) {
-                disposed = true;
-            }
-        };
-        this.on(GroupCallEvent.GroupCallStateChanged, onState);
+        try {
+            this.initCallFeedPromise = this.initLocalCallFeedInternal();
+            await this.initCallFeedPromise;
+        } finally {
+            this.initCallFeedPromise = undefined;
+        }
+    }
+
+    private async initLocalCallFeedInternal(): Promise<void> {
+        logger.log(`groupCall ${this.groupCallId} initLocalCallFeed`);
+
+        let stream: MediaStream;
 
         try {
             stream = await this.client.getMediaHandler().getUserMediaStream(true, this.type === GroupCallType.Video);
         } catch (error) {
             this.state = GroupCallState.LocalCallFeedUninitialized;
             throw error;
-        } finally {
-            this.off(GroupCallEvent.GroupCallStateChanged, onState);
         }
 
-        // The call could've been disposed while we were waiting
-        if (disposed) throw new Error("Group call disposed");
+        // The call could've been disposed while we were waiting, and could
+        // also have been started back up again (hello, React 18) so if we're
+        // still in this 'initializing' state, carry on, otherwise bail.
+        if (this._state !== GroupCallState.InitializingLocalCallFeed) {
+            this.client.getMediaHandler().stopUserMediaStream(stream);
+            throw new Error("Group call disposed while gathering media stream");
+        }
 
         const callFeed = new CallFeed({
             client: this.client,
@@ -396,8 +404,6 @@ export class GroupCall extends TypedEventEmitter<
         this.addUserMediaFeed(callFeed);
 
         this.state = GroupCallState.LocalCallFeedInitialized;
-
-        return callFeed;
     }
 
     public async updateLocalUsermediaStream(stream: MediaStream): Promise<void> {
@@ -575,7 +581,7 @@ export class GroupCall extends TypedEventEmitter<
             );
             this.localCallFeed.setAudioVideoMuted(muted, null);
             // I don't believe its actually necessary to enable these tracks: they
-            // are the one on the groupcall's own CallFeed and are cloned before being
+            // are the one on the GroupCall's own CallFeed and are cloned before being
             // given to any of the actual calls, so these tracks don't actually go
             // anywhere. Let's do it anyway to avoid confusion.
             setTracksEnabled(this.localCallFeed.stream.getAudioTracks(), !muted);
@@ -1182,6 +1188,14 @@ export class GroupCall extends TypedEventEmitter<
      * Recalculates and updates the participant map to match the room state.
      */
     private updateParticipants(): void {
+        const localMember = this.room.getMember(this.client.getUserId()!)!;
+        if (!localMember) {
+            // The client hasn't fetched enough of the room state to get our own member
+            // event. This probably shouldn't happen, but sanity check & exit for now.
+            logger.warn("Tried to update participants before local room member is available");
+            return;
+        }
+
         if (this.participantsExpirationTimer !== null) {
             clearTimeout(this.participantsExpirationTimer);
             this.participantsExpirationTimer = null;
@@ -1236,7 +1250,6 @@ export class GroupCall extends TypedEventEmitter<
 
         // Apply local echo for the entered case
         if (entered) {
-            const localMember = this.room.getMember(this.client.getUserId()!)!;
             let deviceMap = participants.get(localMember);
             if (deviceMap === undefined) {
                 deviceMap = new Map();

src/webrtc/mediaHandler.ts

@@ -57,6 +57,9 @@ export class MediaHandler extends TypedEventEmitter<
     public userMediaStreams: MediaStream[] = [];
     public screensharingStreams: MediaStream[] = [];
 
+    // Promise chain to serialise calls to getMediaStream
+    private getMediaStreamPromise?: Promise<MediaStream>;
+
     public constructor(private client: MatrixClient) {
         super();
     }
@@ -196,6 +199,19 @@ export class MediaHandler extends TypedEventEmitter<
      * @returns based on passed parameters
      */
     public async getUserMediaStream(audio: boolean, video: boolean, reusable = true): Promise<MediaStream> {
+        // Serialise calls, othertwise we can't sensibly re-use the stream
+        if (this.getMediaStreamPromise) {
+            this.getMediaStreamPromise = this.getMediaStreamPromise.then(() => {
+                return this.getUserMediaStreamInternal(audio, video, reusable);
+            });
+        } else {
+            this.getMediaStreamPromise = this.getUserMediaStreamInternal(audio, video, reusable);
+        }
+
+        return this.getMediaStreamPromise;
+    }
+
+    private async getUserMediaStreamInternal(audio: boolean, video: boolean, reusable: boolean): Promise<MediaStream> {
         const shouldRequestAudio = audio && (await this.hasAudioDevice());
         const shouldRequestVideo = video && (await this.hasVideoDevice());