v15.5.2

Co-authored-by: Michael Telatynski <7t3chguy@gmail.com>

CHANGELOG.md

@@ -1,3 +1,100 @@
+Changes in [15.5.2](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v15.5.2) (2022-02-17)
+==================================================================================================
+
+## 🐛 Bug Fixes
+ * Fix synthetic read receipt handling
+
+Changes in [15.5.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v15.5.1) (2022-02-14)
+==================================================================================================
+
+## 🐛 Bug Fixes
+ * Fix issue with rooms not getting marked as unread ([\#2163](https://github.com/matrix-org/matrix-js-sdk/pull/2163)). Fixes vector-im/element-web#20971.
+ * Don't store streams that are only used once ([\#2157](https://github.com/matrix-org/matrix-js-sdk/pull/2157)). Fixes vector-im/element-web#20932. Contributed by @SimonBrandner.
+ * Fix edge cases around RR calculations ([\#2160](https://github.com/matrix-org/matrix-js-sdk/pull/2160)). Fixes vector-im/element-web#20922.
+ * Account for encryption in `maySendMessage()` ([\#2159](https://github.com/matrix-org/matrix-js-sdk/pull/2159)). Contributed by @SimonBrandner.
+ * Send references to thread root to threads, even out of order ([\#2156](https://github.com/matrix-org/matrix-js-sdk/pull/2156)).
+ * Fix initial sync fail when event fetching unsuccessful ([\#2150](https://github.com/matrix-org/matrix-js-sdk/pull/2150)). Fixes vector-im/element-web#20862.
+ * Don't decrypt redacted messages ([\#2143](https://github.com/matrix-org/matrix-js-sdk/pull/2143)). Contributed by @SimonBrandner.
+
+Changes in [15.5.1-rc.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v15.5.1-rc.1) (2022-02-08)
+============================================================================================================
+
+## 🐛 Bug Fixes
+ * Fix issue with rooms not getting marked as unread ([\#2163](https://github.com/matrix-org/matrix-js-sdk/pull/2163)). Fixes vector-im/element-web#20971.
+ * Don't store streams that are only used once ([\#2157](https://github.com/matrix-org/matrix-js-sdk/pull/2157)). Fixes vector-im/element-web#20932. Contributed by @SimonBrandner.
+ * Fix edge cases around RR calculations ([\#2160](https://github.com/matrix-org/matrix-js-sdk/pull/2160)). Fixes vector-im/element-web#20922.
+ * Account for encryption in `maySendMessage()` ([\#2159](https://github.com/matrix-org/matrix-js-sdk/pull/2159)). Contributed by @SimonBrandner.
+ * Send references to thread root to threads, even out of order ([\#2156](https://github.com/matrix-org/matrix-js-sdk/pull/2156)).
+ * Fix initial sync fail when event fetching unsuccessful ([\#2150](https://github.com/matrix-org/matrix-js-sdk/pull/2150)). Fixes vector-im/element-web#20862.
+ * Don't decrypt redacted messages ([\#2143](https://github.com/matrix-org/matrix-js-sdk/pull/2143)). Contributed by @SimonBrandner.
+
+Changes in [15.5.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v15.5.0) (2022-01-31)
+==================================================================================================
+
+## ✨ Features
+ * Support m.asset in m.location event content ([\#2109](https://github.com/matrix-org/matrix-js-sdk/pull/2109)).
+ * Send extensible events structure and support on-demand parsing ([\#2091](https://github.com/matrix-org/matrix-js-sdk/pull/2091)).
+ * Support cancelling events whilst they are in status = ENCRYPTING ([\#2095](https://github.com/matrix-org/matrix-js-sdk/pull/2095)).
+
+## 🐛 Bug Fixes
+ * Fix http-api butchering idServer requests ([\#2134](https://github.com/matrix-org/matrix-js-sdk/pull/2134)). Fixes vector-im/element-web#20680.
+ * Don't remove streams that still have tracks ([\#2104](https://github.com/matrix-org/matrix-js-sdk/pull/2104)).
+
+Changes in [15.5.0-rc.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v15.5.0-rc.1) (2022-01-26)
+============================================================================================================
+
+## ✨ Features
+ * Support m.asset in m.location event content ([\#2109](https://github.com/matrix-org/matrix-js-sdk/pull/2109)).
+ * Send extensible events structure and support on-demand parsing ([\#2091](https://github.com/matrix-org/matrix-js-sdk/pull/2091)).
+ * Support cancelling events whilst they are in status = ENCRYPTING ([\#2095](https://github.com/matrix-org/matrix-js-sdk/pull/2095)).
+
+## 🐛 Bug Fixes
+ * Fix http-api butchering idServer requests ([\#2134](https://github.com/matrix-org/matrix-js-sdk/pull/2134)). Fixes vector-im/element-web#20680.
+ * Don't remove streams that still have tracks ([\#2104](https://github.com/matrix-org/matrix-js-sdk/pull/2104)).
+
+Changes in [15.4.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v15.4.0) (2022-01-17)
+==================================================================================================
+
+## ✨ Features
+ * Don't consider alt_aliases when calculating room name ([\#2094](https://github.com/matrix-org/matrix-js-sdk/pull/2094)). Fixes vector-im/element-web#13887.
+ * Load room history if necessary when searching for MSC3089 getFileEvent() ([\#2066](https://github.com/matrix-org/matrix-js-sdk/pull/2066)).
+ * Add support for MSC3030 `/timestamp_to_event` ([\#2072](https://github.com/matrix-org/matrix-js-sdk/pull/2072)).
+
+## 🐛 Bug Fixes
+ * Stop encrypting redactions as it isn't spec compliant ([\#2098](https://github.com/matrix-org/matrix-js-sdk/pull/2098)). Fixes vector-im/element-web#20460.
+ * Fix more function typings relating to key backup ([\#2086](https://github.com/matrix-org/matrix-js-sdk/pull/2086)).
+ * Fix timeline search in MSC3089 getFileEvent() ([\#2085](https://github.com/matrix-org/matrix-js-sdk/pull/2085)).
+ * Set a `deviceId` for VoIP example and use `const`/`let` ([\#2090](https://github.com/matrix-org/matrix-js-sdk/pull/2090)). Fixes #2083. Contributed by @SimonBrandner.
+ * Fix incorrect TS return type for secret storage and key backup functions ([\#2082](https://github.com/matrix-org/matrix-js-sdk/pull/2082)).
+
+Changes in [15.4.0-rc.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v15.4.0-rc.1) (2022-01-11)
+============================================================================================================
+
+## ✨ Features
+ * Don't consider alt_aliases when calculating room name ([\#2094](https://github.com/matrix-org/matrix-js-sdk/pull/2094)). Fixes vector-im/element-web#13887.
+ * Load room history if necessary when searching for MSC3089 getFileEvent() ([\#2066](https://github.com/matrix-org/matrix-js-sdk/pull/2066)).
+ * Add support for MSC3030 `/timestamp_to_event` ([\#2072](https://github.com/matrix-org/matrix-js-sdk/pull/2072)).
+
+## 🐛 Bug Fixes
+ * Stop encrypting redactions as it isn't spec compliant ([\#2098](https://github.com/matrix-org/matrix-js-sdk/pull/2098)). Fixes vector-im/element-web#20460.
+ * Fix more function typings relating to key backup ([\#2086](https://github.com/matrix-org/matrix-js-sdk/pull/2086)).
+ * Fix timeline search in MSC3089 getFileEvent() ([\#2085](https://github.com/matrix-org/matrix-js-sdk/pull/2085)).
+ * Set a `deviceId` for VoIP example and use `const`/`let` ([\#2090](https://github.com/matrix-org/matrix-js-sdk/pull/2090)). Fixes #2083. Contributed by @SimonBrandner.
+ * Fix incorrect TS return type for secret storage and key backup functions ([\#2082](https://github.com/matrix-org/matrix-js-sdk/pull/2082)).
+
+Changes in [15.3.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v15.3.0) (2021-12-20)
+==================================================================================================
+
+## ✨ Features
+ * Improve fallback key behaviour ([\#2037](https://github.com/matrix-org/matrix-js-sdk/pull/2037)).
+ * Add new room event filter fields ([\#2051](https://github.com/matrix-org/matrix-js-sdk/pull/2051)).
+ * Add method to fetch /account/whoami ([\#2046](https://github.com/matrix-org/matrix-js-sdk/pull/2046)).
+
+## 🐛 Bug Fixes
+ * Filter out falsey opts in /relations API hits ([\#2059](https://github.com/matrix-org/matrix-js-sdk/pull/2059)). Fixes vector-im/element-web#20137.
+ * Fix paginateEventTimeline resolve to boolean ([\#2054](https://github.com/matrix-org/matrix-js-sdk/pull/2054)).
+ * Fix incorrect MSC3089 typings and add null checks ([\#2049](https://github.com/matrix-org/matrix-js-sdk/pull/2049)).
+
 Changes in [15.3.0-rc.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v15.3.0-rc.1) (2021-12-14)
 ============================================================================================================
 

examples/voip/browserTest.js

@@ -1,16 +1,17 @@
 console.log("Loading browser sdk");
-var BASE_URL = "https://matrix.org";
-var TOKEN = "accesstokengoeshere";
-var USER_ID = "@username:localhost";
-var ROOM_ID = "!room:id";
+const BASE_URL = "https://matrix.org";
+const TOKEN = "accesstokengoeshere";
+const USER_ID = "@username:localhost";
+const ROOM_ID = "!room:id";
+const DEVICE_ID = "some_device_id";
 
-
-var client = matrixcs.createClient({
+const client = matrixcs.createClient({
     baseUrl: BASE_URL,
     accessToken: TOKEN,
-    userId: USER_ID
+    userId: USER_ID,
+    deviceId: DEVICE_ID
 });
-var call;
+let call;
 
 function disableButtons(place, answer, hangup) {
     document.getElementById("hangup").disabled = hangup;
@@ -19,7 +20,7 @@ function disableButtons(place, answer, hangup) {
 }
 
 function addListeners(call) {
-    var lastError = "";
+    let lastError = "";
     call.on("hangup", function() {
         disableButtons(false, true, true);
         document.getElementById("result").innerHTML = (

package.json

@@ -1,6 +1,6 @@
 {
   "name": "matrix-js-sdk",
-  "version": "15.3.0-rc.1",
+  "version": "15.5.2",
   "description": "Matrix Client-Server SDK for Javascript",
   "scripts": {
     "prepublishOnly": "yarn build",
@@ -15,7 +15,7 @@
     "build:minify-browser": "terser dist/browser-matrix.js --compress --mangle --source-map --output dist/browser-matrix.min.js",
     "gendoc": "jsdoc -c jsdoc.json -P package.json",
     "lint": "yarn lint:types && yarn lint:js",
-    "lint:js": "eslint --max-warnings 4 src spec",
+    "lint:js": "eslint --max-warnings 0 src spec",
     "lint:js-fix": "eslint --fix src spec",
     "lint:types": "tsc --noEmit",
     "test": "jest",
@@ -55,8 +55,8 @@
     "browser-request": "^0.3.3",
     "bs58": "^4.0.1",
     "content-type": "^1.0.4",
-    "eslint-plugin-import": "^2.25.2",
     "loglevel": "^1.7.1",
+    "matrix-events-sdk": "^0.0.1-beta.6",
     "p-retry": "^4.5.0",
     "qs": "^6.9.6",
     "request": "^2.88.2",
@@ -77,6 +77,7 @@
     "@babel/register": "^7.12.10",
     "@matrix-org/olm": "https://gitlab.matrix.org/api/v4/projects/27/packages/npm/@matrix-org/olm/-/@matrix-org/olm-3.2.8.tgz",
     "@types/bs58": "^4.0.1",
+    "@types/content-type": "^1.1.5",
     "@types/jest": "^26.0.20",
     "@types/node": "12",
     "@types/request": "^2.48.5",
@@ -90,7 +91,8 @@
     "docdash": "^1.2.0",
     "eslint": "7.18.0",
     "eslint-config-google": "^0.14.0",
-    "eslint-plugin-matrix-org": "github:matrix-org/eslint-plugin-matrix-org#48ec1e6af2cfb8310b9a6e23edf2dc7a26ddd580",
+    "eslint-plugin-import": "^2.25.4",
+    "eslint-plugin-matrix-org": "^0.4.0",
     "exorcist": "^1.0.1",
     "fake-indexeddb": "^3.1.2",
     "jest": "^26.6.3",

release.sh

@@ -255,6 +255,12 @@ if [ -n "$signing_id" ]; then
     # the easiest way to check the validity of the tarball from git is to unzip
     # it and compare it with our own idea of what the tar should look like.
 
+    # This uses git archive which seems to be what github uses. Specifically,
+    # the header fields are set in the same way: same file mode, uid & gid
+    # both zero and mtime set to the timestamp of the commit that the tag
+    # references. Also note that this puts the commit into the tar headers
+    # and can be extracted with gunzip -c foo.tar.gz | git get-tar-commit-id
+
     # the name of the sig file we want to create
     source_sigfile="${tag}-src.tar.gz.asc"
 

spec/TestClient.js

@@ -86,6 +86,7 @@ TestClient.prototype.toString = function() {
  */
 TestClient.prototype.start = function() {
     logger.log(this + ': starting');
+    this.httpBackend.when("GET", "/capabilities").respond(200, { capabilities: {} });
     this.httpBackend.when("GET", "/pushrules").respond(200, {});
     this.httpBackend.when("POST", "/filter").respond(200, { filter_id: "fid" });
     this.expectDeviceKeyUpload();

spec/browserify/sync-browserify.spec.js

@@ -17,55 +17,34 @@ limitations under the License.
 // load XmlHttpRequest mock
 import "./setupTests";
 import "../../dist/browser-matrix"; // uses browser-matrix instead of the src
-import MockHttpBackend from "matrix-mock-request";
-
-import { MockStorageApi } from "../MockStorageApi";
-import { WebStorageSessionStore } from "../../src/store/session/webstorage";
-import { LocalStorageCryptoStore } from "../../src/crypto/store/localStorage-crypto-store";
 import * as utils from "../test-utils";
+import { TestClient } from "../TestClient";
 
 const USER_ID = "@user:test.server";
 const DEVICE_ID = "device_id";
 const ACCESS_TOKEN = "access_token";
 const ROOM_ID = "!room_id:server.test";
 
-/* global matrixcs */
-
 describe("Browserify Test", function() {
     let client;
     let httpBackend;
 
-    async function createTestClient() {
-        const sessionStoreBackend = new MockStorageApi();
-        const sessionStore = new WebStorageSessionStore(sessionStoreBackend);
-        const httpBackend = new MockHttpBackend();
+    beforeEach(() => {
+        const testClient = new TestClient(USER_ID, DEVICE_ID, ACCESS_TOKEN);
 
-        const options = {
-            baseUrl: "http://" + USER_ID + ".test.server",
-            userId: USER_ID,
-            accessToken: ACCESS_TOKEN,
-            deviceId: DEVICE_ID,
-            sessionStore: sessionStore,
-            request: httpBackend.requestFn,
-            cryptoStore: new LocalStorageCryptoStore(sessionStoreBackend),
-        };
-
-        const client = matrixcs.createClient(options);
+        client = testClient.client;
+        httpBackend = testClient.httpBackend;
 
+        httpBackend.when("GET", "/capabilities").respond(200, { capabilities: {} });
         httpBackend.when("GET", "/pushrules").respond(200, {});
         httpBackend.when("POST", "/filter").respond(200, { filter_id: "fid" });
 
-        return { client, httpBackend };
-    }
-
-    beforeEach(async () => {
-        ({ client, httpBackend } = await createTestClient());
-        await client.startClient();
+        client.startClient();
     });
 
     afterEach(async () => {
         client.stopClient();
-        await httpBackend.stop();
+        httpBackend.stop();
     });
 
     it("Sync", async function() {
@@ -92,10 +71,8 @@ describe("Browserify Test", function() {
         };
 
         httpBackend.when("GET", "/sync").respond(200, syncData);
-        await Promise.race([
-            Promise.all([
-                httpBackend.flushAllExpected(),
-            ]),
+        return await Promise.race([
+            httpBackend.flushAllExpected(),
             new Promise((_, reject) => {
                 client.once("sync.unexpectedError", reject);
             }),

spec/integ/matrix-client-crypto.spec.js

@@ -348,7 +348,7 @@ function recvMessage(httpBackend, client, sender, message) {
         return testUtils.awaitDecryption(event);
     }).then((event) => {
         expect(event.getType()).toEqual("m.room.message");
-        expect(event.getContent()).toEqual({
+        expect(event.getContent()).toMatchObject({
             msgtype: "m.text",
             body: "Hello, World",
         });
@@ -722,6 +722,7 @@ describe("MatrixClient crypto", function() {
         return Promise.resolve()
             .then(() => {
                 logger.log(aliTestClient + ': starting');
+                httpBackend.when("GET", "/capabilities").respond(200, {});
                 httpBackend.when("GET", "/pushrules").respond(200, {});
                 httpBackend.when("POST", "/filter").respond(200, { filter_id: "fid" });
                 aliTestClient.expectDeviceKeyUpload();

spec/integ/matrix-client-event-emitter.spec.js

@@ -13,6 +13,7 @@ describe("MatrixClient events", function() {
         httpBackend = testClient.httpBackend;
         httpBackend.when("GET", "/pushrules").respond(200, {});
         httpBackend.when("POST", "/filter").respond(200, { filter_id: "a filter id" });
+        httpBackend.when("GET", "/capabilities").respond(200, { capabilities: {} });
     });
 
     afterEach(function() {

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

@@ -71,6 +71,7 @@ const EVENTS = [
 
 // start the client, and wait for it to initialise
 function startClient(httpBackend, client) {
+    httpBackend.when("GET", "/capabilities").respond(200, { capabilities: {} });
     httpBackend.when("GET", "/pushrules").respond(200, {});
     httpBackend.when("POST", "/filter").respond(200, { filter_id: "fid" });
     httpBackend.when("GET", "/sync").respond(200, INITIAL_SYNC_DATA);
@@ -502,7 +503,7 @@ describe("MatrixClient event timelines", function() {
                     const params = req.queryParams;
                     expect(params.dir).toEqual("b");
                     expect(params.from).toEqual("start_token0");
-                    expect(params.limit).toEqual(30);
+                    expect(params.limit).toEqual("30");
                 }).respond(200, function() {
                     return {
                         chunk: [EVENTS[1], EVENTS[2]],
@@ -553,7 +554,7 @@ describe("MatrixClient event timelines", function() {
                     const params = req.queryParams;
                     expect(params.dir).toEqual("f");
                     expect(params.from).toEqual("end_token0");
-                    expect(params.limit).toEqual(20);
+                    expect(params.limit).toEqual("20");
                 }).respond(200, function() {
                     return {
                         chunk: [EVENTS[1], EVENTS[2]],

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

@@ -1,7 +1,9 @@
 import * as utils from "../test-utils";
 import { CRYPTO_ENABLED } from "../../src/client";
+import { MatrixEvent } from "../../src/models/event";
 import { Filter, MemoryStore, Room } from "../../src/matrix";
 import { TestClient } from "../TestClient";
+import { Thread } from "../../src/models/thread";
 
 describe("MatrixClient", function() {
     let client = null;
@@ -392,6 +394,492 @@ describe("MatrixClient", function() {
             return prom;
         });
     });
+
+    describe("partitionThreadedEvents", function() {
+        it("returns empty arrays when given an empty arrays", function() {
+            const events = [];
+            const [timeline, threaded] = client.partitionThreadedEvents(events);
+            expect(timeline).toEqual([]);
+            expect(threaded).toEqual([]);
+        });
+
+        it("copies pre-thread in-timeline vote events onto both timelines", function() {
+            client.clientOpts = { experimentalThreadSupport: true };
+            const events = [
+                eventMessageInThread,
+                eventPollResponseReference,
+                eventPollStartThreadRoot,
+            ];
+            // Vote has no threadId yet
+            expect(eventPollResponseReference.threadId).toBeFalsy();
+
+            const [timeline, threaded] = client.partitionThreadedEvents(events);
+
+            expect(timeline).toEqual([
+                // The message that was sent in a thread is missing
+                eventPollResponseReference,
+                eventPollStartThreadRoot,
+            ]);
+
+            // The vote event has been copied into the thread
+            const eventRefWithThreadId = withThreadId(
+                eventPollResponseReference, eventPollStartThreadRoot.getId());
+            expect(eventRefWithThreadId.threadId).toBeTruthy();
+
+            expect(threaded).toEqual([
+                eventMessageInThread,
+                eventRefWithThreadId,
+                // Thread does not see thread root
+            ]);
+        });
+
+        it("copies pre-thread in-timeline reactions onto both timelines", function() {
+            client.clientOpts = { experimentalThreadSupport: true };
+            const events = [
+                eventMessageInThread,
+                eventReaction,
+                eventPollStartThreadRoot,
+            ];
+
+            const [timeline, threaded] = client.partitionThreadedEvents(events);
+
+            expect(timeline).toEqual([
+                eventReaction,
+                eventPollStartThreadRoot,
+            ]);
+
+            expect(threaded).toEqual([
+                eventMessageInThread,
+                withThreadId(eventReaction, eventPollStartThreadRoot.getId()),
+            ]);
+        });
+
+        it("copies post-thread in-timeline vote events onto both timelines", function() {
+            client.clientOpts = { experimentalThreadSupport: true };
+            const events = [
+                eventPollResponseReference,
+                eventMessageInThread,
+                eventPollStartThreadRoot,
+            ];
+
+            const [timeline, threaded] = client.partitionThreadedEvents(events);
+
+            expect(timeline).toEqual([
+                eventPollResponseReference,
+                eventPollStartThreadRoot,
+            ]);
+
+            expect(threaded).toEqual([
+                withThreadId(eventPollResponseReference, eventPollStartThreadRoot.getId()),
+                eventMessageInThread,
+            ]);
+        });
+
+        it("copies post-thread in-thread vote events onto both timelines", function() {
+            client.clientOpts = { experimentalThreadSupport: true };
+
+            // Events for this test only, because we hack around with them
+            const eventMessageInThread2 = new MatrixEvent({
+                "age": 80098509,
+                "content": {
+                    "algorithm": "m.megolm.v1.aes-sha2",
+                    "ciphertext": "ENCRYPTEDSTUFF",
+                    "device_id": "XISFUZSKHH",
+                    "m.relates_to": {
+                        "event_id": "$AAA2ojbPmxb6x8ECetn45hmND6cRDcjgv-j-to9m7Vo",
+                        "m.in_reply_to": {
+                            "event_id": "$AAA2ojbPmxb6x8ECetn45hmND6cRDcjgv-j-to9m7Vo",
+                        },
+                        "rel_type": "io.element.thread",
+                    },
+                    "sender_key": "i3N3CtG/CD2bGB8rA9fW6adLYSDvlUhf2iuU73L65Vg",
+                    "session_id": "Ja11R/KG6ua0wdk8zAzognrxjio1Gm/RK2Gn6lFL804",
+                },
+                "event_id": "$AAAhKIGYowtBblVLkRimeIg8TcdjETnxhDPGfi6NpDg",
+                "origin_server_ts": 1643815466378,
+                "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+                "sender": "@andybalaam-test1:matrix.org",
+                "type": "m.room.encrypted",
+                "unsigned": { "age": 80098509 },
+                "user_id": "@andybalaam-test1:matrix.org",
+            });
+
+            const eventPollStartThreadRoot2 = new MatrixEvent({
+                "age": 80108647,
+                "content": {
+                    "algorithm": "m.megolm.v1.aes-sha2",
+                    "ciphertext": "ENCRYPTEDSTUFF",
+                    "device_id": "XISFUZSKHH",
+                    "sender_key": "i3N3CtG/CD2bGB8rA9fW6adLYSDvlUhf2iuU73L65Vg",
+                    "session_id": "Ja11R/KG6ua0wdk8zAzognrxjio1Gm/RK2Gn6lFL804",
+                },
+                "event_id": "$AAA2ojbPmxb6x8ECetn45hmND6cRDcjgv-j-to9m7Vo",
+                "origin_server_ts": 1643815456240,
+                "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+                "sender": "@andybalaam-test1:matrix.org",
+                "type": "m.room.encrypted",
+                "unsigned": { "age": 80108647 },
+                "user_id": "@andybalaam-test1:matrix.org",
+            });
+
+            const eventPollResponseReference2 = new MatrixEvent({
+                "age": 80098509,
+                "content": {
+                    "algorithm": "m.megolm.v1.aes-sha2",
+                    "ciphertext": "ENCRYPTEDSTUFF",
+                    "device_id": "XISFUZSKHH",
+                    "m.relates_to": {
+                        "event_id": "$AAA2ojbPmxb6x8ECetn45hmND6cRDcjgv-j-to9m7Vo",
+                        "rel_type": "m.reference",
+                    },
+                    "sender_key": "i3N3CtG/CD2bGB8rA9fW6adLYSDvlUhf2iuU73L65Vg",
+                    "session_id": "Ja11R/KG6ua0wdk8zAzognrxjio1Gm/RK2Gn6lFL804",
+                },
+                "event_id": "$AAAvpezvsF0cKgav3g8W-uEVS4WkDHgxbJZvL3uMR1g",
+                "origin_server_ts": 1643815458650,
+                "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+                "sender": "@andybalaam-test1:matrix.org",
+                "type": "m.room.encrypted",
+                "unsigned": { "age": 80106237 },
+                "user_id": "@andybalaam-test1:matrix.org",
+            });
+
+            // When we react within a thread, sometimes the thread root
+            // has isThreadRelation === true, because thread is set on it,
+            // but threadId is not.
+            eventPollStartThreadRoot2.setThread(
+                new Thread(
+                    eventPollStartThreadRoot2,
+                    {
+                        client,
+                        room: new Room(),
+                    },
+                ),
+            );
+
+            const events = [
+                eventPollResponseReference2,
+                eventMessageInThread2,
+                eventPollStartThreadRoot2,
+            ];
+
+            const [timeline, threaded] = client.partitionThreadedEvents(events);
+
+            expect(timeline).toEqual([
+                eventPollResponseReference2,
+                // eventPollStartThreadRoot2,
+                // This is weird: by hacking the thread root to have an inconsistency
+                // between thread and threadId (which is what I have observed in the
+                // wild), we have persuaded the code that the thread root is actually
+                // within the thread, so it is not provided to the main timeline.
+                //
+                // This should go away when we fix this inconsistency.  When that
+                // happens, we should probably delete this test.
+            ]);
+
+            expect(threaded).toEqual([
+                withThreadId(
+                    eventPollResponseReference2, eventPollStartThreadRoot2.getId(),
+                ),
+                eventMessageInThread2,
+                eventPollStartThreadRoot2, // See note above for why this appears here.
+            ]);
+        });
+
+        it("copies post-thread in-timeline reactions onto both timelines", function() {
+            client.clientOpts = { experimentalThreadSupport: true };
+            const events = [
+                eventReaction,
+                eventMessageInThread,
+                eventPollStartThreadRoot,
+            ];
+
+            const [timeline, threaded] = client.partitionThreadedEvents(events);
+
+            expect(timeline).toEqual([
+                eventReaction,
+                eventPollStartThreadRoot,
+            ]);
+
+            expect(threaded).toEqual([
+                withThreadId(eventReaction, eventPollStartThreadRoot.getId()),
+                eventMessageInThread,
+            ]);
+        });
+
+        it("sends room state events to the main timeline only", function() {
+            client.clientOpts = { experimentalThreadSupport: true };
+            // This is based on recording the events in a real room:
+            const events = [
+                eventMessageInThread,
+                eventPollResponseReference,
+                eventPollStartThreadRoot,
+                eventRoomName,
+                eventEncryption,
+                eventGuestAccess,
+                eventHistoryVisibility,
+                eventJoinRules,
+                eventPowerLevels,
+                eventMember,
+                eventCreate,
+            ];
+            const [timeline, threaded] = client.partitionThreadedEvents(events);
+
+            expect(timeline).toEqual([
+                // The message that was sent in a thread is missing
+                eventPollResponseReference,
+                eventPollStartThreadRoot,
+                eventRoomName,
+                eventEncryption,
+                eventGuestAccess,
+                eventHistoryVisibility,
+                eventJoinRules,
+                eventPowerLevels,
+                eventMember,
+                eventCreate,
+            ]);
+
+            // Thread should contain only stuff that happened in the thread -
+            // no thread root, and no room state events
+            expect(threaded).toEqual([
+                eventMessageInThread,
+                withThreadId(eventPollResponseReference, eventPollStartThreadRoot.getId()),
+            ]);
+        });
+    });
+});
+
+function withThreadId(event, newThreadId) {
+    const ret = event.toSnapshot();
+    ret.setThreadId(newThreadId);
+    return ret;
+}
+
+const eventMessageInThread = new MatrixEvent({
+    "age": 80098509,
+    "content": {
+        "algorithm": "m.megolm.v1.aes-sha2",
+        "ciphertext": "ENCRYPTEDSTUFF",
+        "device_id": "XISFUZSKHH",
+        "m.relates_to": {
+            "event_id": "$VLS2ojbPmxb6x8ECetn45hmND6cRDcjgv-j-to9m7Vo",
+            "m.in_reply_to": {
+                "event_id": "$VLS2ojbPmxb6x8ECetn45hmND6cRDcjgv-j-to9m7Vo",
+            },
+            "rel_type": "io.element.thread",
+        },
+        "sender_key": "i3N3CtG/CD2bGB8rA9fW6adLYSDvlUhf2iuU73L65Vg",
+        "session_id": "Ja11R/KG6ua0wdk8zAzognrxjio1Gm/RK2Gn6lFL804",
+    },
+    "event_id": "$W4chKIGYowtBblVLkRimeIg8TcdjETnxhDPGfi6NpDg",
+    "origin_server_ts": 1643815466378,
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+    "sender": "@andybalaam-test1:matrix.org",
+    "type": "m.room.encrypted",
+    "unsigned": { "age": 80098509 },
+    "user_id": "@andybalaam-test1:matrix.org",
+});
+
+const eventPollResponseReference = new MatrixEvent({
+    "age": 80098509,
+    "content": {
+        "algorithm": "m.megolm.v1.aes-sha2",
+        "ciphertext": "ENCRYPTEDSTUFF",
+        "device_id": "XISFUZSKHH",
+        "m.relates_to": {
+            "event_id": "$VLS2ojbPmxb6x8ECetn45hmND6cRDcjgv-j-to9m7Vo",
+            "rel_type": "m.reference",
+        },
+        "sender_key": "i3N3CtG/CD2bGB8rA9fW6adLYSDvlUhf2iuU73L65Vg",
+        "session_id": "Ja11R/KG6ua0wdk8zAzognrxjio1Gm/RK2Gn6lFL804",
+    },
+    "event_id": "$91JvpezvsF0cKgav3g8W-uEVS4WkDHgxbJZvL3uMR1g",
+    "origin_server_ts": 1643815458650,
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+    "sender": "@andybalaam-test1:matrix.org",
+    "type": "m.room.encrypted",
+    "unsigned": { "age": 80106237 },
+    "user_id": "@andybalaam-test1:matrix.org",
+});
+
+const eventReaction = new MatrixEvent({
+    "content": {
+        "m.relates_to": {
+            "event_id": "$VLS2ojbPmxb6x8ECetn45hmND6cRDcjgv-j-to9m7Vo",
+            "key": "🤗",
+            "rel_type": "m.annotation",
+        },
+    },
+    "origin_server_ts": 1643977249238,
+    "sender": "@andybalaam-test1:matrix.org",
+    "type": "m.reaction",
+    "unsigned": {
+        "age": 22598,
+        "transaction_id": "m1643977249073.16",
+    },
+    "event_id": "$86B2b-x3LgE4DlV4y24b7UHnt72LIA3rzjvMysTtAfA",
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+});
+
+const eventPollStartThreadRoot = new MatrixEvent({
+    "age": 80108647,
+    "content": {
+        "algorithm": "m.megolm.v1.aes-sha2",
+        "ciphertext": "ENCRYPTEDSTUFF",
+        "device_id": "XISFUZSKHH",
+        "sender_key": "i3N3CtG/CD2bGB8rA9fW6adLYSDvlUhf2iuU73L65Vg",
+        "session_id": "Ja11R/KG6ua0wdk8zAzognrxjio1Gm/RK2Gn6lFL804",
+    },
+    "event_id": "$VLS2ojbPmxb6x8ECetn45hmND6cRDcjgv-j-to9m7Vo",
+    "origin_server_ts": 1643815456240,
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+    "sender": "@andybalaam-test1:matrix.org",
+    "type": "m.room.encrypted",
+    "unsigned": { "age": 80108647 },
+    "user_id": "@andybalaam-test1:matrix.org",
+});
+
+const eventRoomName = new MatrixEvent({
+    "age": 80123249,
+    "content": {
+        "name": "1 poll, 1 vote, 1 thread",
+    },
+    "event_id": "$QAdyNJtKnl1j7or2yMycbOCvb6bCgvHs5lg3ZMd5xWk",
+    "origin_server_ts": 1643815441638,
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+    "sender": "@andybalaam-test1:matrix.org",
+    "state_key": "",
+    "type": "m.room.name",
+    "unsigned": { "age": 80123249 },
+    "user_id": "@andybalaam-test1:matrix.org",
+});
+
+const eventEncryption = new MatrixEvent({
+    "age": 80123383,
+    "content": {
+        "algorithm": "m.megolm.v1.aes-sha2",
+    },
+    "event_id": "$1hGykogKQkXbHw8bVuyE3BjHnFBEJBcUWnakd0ck2K0",
+    "origin_server_ts": 1643815441504,
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+    "sender": "@andybalaam-test1:matrix.org",
+    "state_key": "",
+    "type": "m.room.encryption",
+    "unsigned": { "age": 80123383 },
+    "user_id": "@andybalaam-test1:matrix.org",
+});
+
+const eventGuestAccess = new MatrixEvent({
+    "age": 80123473,
+    "content": {
+        "guest_access": "can_join",
+    },
+    "event_id": "$4_2n-H6K9-0nPbnjjtIue2SU44tGJsnuTmi6UuSrh-U",
+    "origin_server_ts": 1643815441414,
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+    "sender": "@andybalaam-test1:matrix.org",
+    "state_key": "",
+    "type": "m.room.guest_access",
+    "unsigned": { "age": 80123473 },
+    "user_id": "@andybalaam-test1:matrix.org",
+});
+
+const eventHistoryVisibility = new MatrixEvent({
+    "age": 80123556,
+    "content": {
+        "history_visibility": "shared",
+    },
+    "event_id": "$W6kp44CTnvciOiHSPyhp8dh4n2v1_9kclUPddeaQj0E",
+    "origin_server_ts": 1643815441331,
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+    "sender": "@andybalaam-test1:matrix.org",
+    "state_key": "",
+    "type": "m.room.history_visibility",
+    "unsigned": { "age": 80123556 },
+    "user_id": "@andybalaam-test1:matrix.org",
+});
+
+const eventJoinRules = new MatrixEvent({
+    "age": 80123696,
+    "content": {
+        "join_rule": "invite",
+    },
+    "event_id": "$6JDDeDp7fEc0F6YnTWMruNcKWFltR3e9wk7wWDDJrAU",
+    "origin_server_ts": 1643815441191,
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+    "sender": "@andybalaam-test1:matrix.org",
+    "state_key": "",
+    "type": "m.room.join_rules",
+    "unsigned": { "age": 80123696 },
+    "user_id": "@andybalaam-test1:matrix.org",
+});
+
+const eventPowerLevels = new MatrixEvent({
+    "age": 80124105,
+    "content": {
+        "ban": 50,
+        "events": {
+            "m.room.avatar": 50,
+            "m.room.canonical_alias": 50,
+            "m.room.encryption": 100,
+            "m.room.history_visibility": 100,
+            "m.room.name": 50,
+            "m.room.power_levels": 100,
+            "m.room.server_acl": 100,
+            "m.room.tombstone": 100,
+        },
+        "events_default": 0,
+        "historical": 100,
+        "invite": 0,
+        "kick": 50,
+        "redact": 50,
+        "state_default": 50,
+        "users": {
+            "@andybalaam-test1:matrix.org": 100,
+        },
+        "users_default": 0,
+    },
+    "event_id": "$XZY2YgQhXskpc7gmJJG3S0VmS9_QjjCUVeeFTfgfC2E",
+    "origin_server_ts": 1643815440782,
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+    "sender": "@andybalaam-test1:matrix.org",
+    "state_key": "",
+    "type": "m.room.power_levels",
+    "unsigned": { "age": 80124105 },
+    "user_id": "@andybalaam-test1:matrix.org",
+});
+
+const eventMember = new MatrixEvent({
+    "age": 80125279,
+    "content": {
+        "avatar_url": "mxc://matrix.org/aNtbVcFfwotudypZcHsIcPOc",
+        "displayname": "andybalaam-test1",
+        "membership": "join",
+    },
+    "event_id": "$Ex5eVmMs_ti784mo8bgddynbwLvy6231lCycJr7Cl9M",
+    "origin_server_ts": 1643815439608,
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+    "sender": "@andybalaam-test1:matrix.org",
+    "state_key": "@andybalaam-test1:matrix.org",
+    "type": "m.room.member",
+    "unsigned": { "age": 80125279 },
+    "user_id": "@andybalaam-test1:matrix.org",
+});
+
+const eventCreate = new MatrixEvent({
+    "age": 80126105,
+    "content": {
+        "creator": "@andybalaam-test1:matrix.org",
+        "room_version": "6",
+    },
+    "event_id": "$e7j2Gt37k5NPwB6lz2N3V9lO5pUdNK8Ai7i2FPEK-oI",
+    "origin_server_ts": 1643815438782,
+    "room_id": "!STrMRsukXHtqQdSeHa:matrix.org",
+    "sender": "@andybalaam-test1:matrix.org",
+    "state_key": "",
+    "type": "m.room.create",
+    "unsigned": { "age": 80126105 },
+    "user_id": "@andybalaam-test1:matrix.org",
 });
 
 function assertObjectContains(obj, expected) {

spec/integ/matrix-client-opts.spec.js

@@ -105,10 +105,12 @@ describe("MatrixClient opts", function() {
                     expectedEventTypes.indexOf(event.getType()), 1,
                 );
             });
+            httpBackend.when("GET", "/capabilities").respond(200, { capabilities: {} });
             httpBackend.when("GET", "/pushrules").respond(200, {});
             httpBackend.when("POST", "/filter").respond(200, { filter_id: "foo" });
             httpBackend.when("GET", "/sync").respond(200, syncData);
-            await client.startClient();
+            client.startClient();
+            await httpBackend.flush("/capabilities", 1);
             await httpBackend.flush("/pushrules", 1);
             await httpBackend.flush("/filter", 1);
             await Promise.all([

spec/integ/matrix-client-room-timeline.spec.js

@@ -96,7 +96,7 @@ describe("MatrixClient room timelines", function() {
         });
     }
 
-    beforeEach(function() {
+    beforeEach(async function() {
         // these tests should work with or without timelineSupport
         const testClient = new TestClient(
             userId,
@@ -109,6 +109,7 @@ describe("MatrixClient room timelines", function() {
         client = testClient.client;
 
         setNextSyncData();
+        httpBackend.when("GET", "/capabilities").respond(200, { capabilities: {} });
         httpBackend.when("GET", "/pushrules").respond(200, {});
         httpBackend.when("POST", "/filter").respond(200, { filter_id: "fid" });
         httpBackend.when("GET", "/sync").respond(200, SYNC_DATA);
@@ -116,9 +117,10 @@ describe("MatrixClient room timelines", function() {
             return NEXT_SYNC_DATA;
         });
         client.startClient();
-        return httpBackend.flush("/pushrules").then(function() {
-            return httpBackend.flush("/filter");
-        });
+
+        await httpBackend.flush("/capabilities");
+        await httpBackend.flush("/pushrules");
+        await httpBackend.flush("/filter");
     });
 
     afterEach(function() {

spec/integ/matrix-client-syncing.spec.js

@@ -19,6 +19,7 @@ describe("MatrixClient syncing", function() {
         const testClient = new TestClient(selfUserId, "DEVICE", selfAccessToken);
         httpBackend = testClient.httpBackend;
         client = testClient.client;
+        httpBackend.when("GET", "/capabilities").respond(200, { capabilities: {} });
         httpBackend.when("GET", "/pushrules").respond(200, {});
         httpBackend.when("POST", "/filter").respond(200, { filter_id: "a filter id" });
     });

spec/test-utils.js

@@ -341,8 +341,15 @@ HttpResponse.SYNC_RESPONSE = {
     data: HttpResponse.SYNC_DATA,
 };
 
+HttpResponse.CAPABILITIES_RESPONSE = {
+    method: "GET",
+    path: "/capabilities",
+    data: { capabilities: {} },
+};
+
 HttpResponse.defaultResponses = function(userId) {
     return [
+        HttpResponse.CAPABILITIES_RESPONSE,
         HttpResponse.PUSH_RULES_RESPONSE,
         HttpResponse.filterResponse(userId),
         HttpResponse.SYNC_RESPONSE,
@@ -350,19 +357,13 @@ HttpResponse.defaultResponses = function(userId) {
 };
 
 export function setHttpResponses(
-    client, responses, acceptKeepalives, ignoreUnhandledSyncs,
+    httpBackend, responses,
 ) {
-    const httpResponseObj = new HttpResponse(
-        responses, acceptKeepalives, ignoreUnhandledSyncs,
-    );
-
-    const httpReq = httpResponseObj.request.bind(httpResponseObj);
-    client.http = [
-        "authedRequest", "authedRequestWithPrefix", "getContentUri",
-        "request", "requestWithPrefix", "uploadContent",
-    ].reduce((r, k) => {r[k] = jest.fn(); return r;}, {});
-    client.http.authedRequest.mockImplementation(httpReq);
-    client.http.authedRequestWithPrefix.mockImplementation(httpReq);
-    client.http.requestWithPrefix.mockImplementation(httpReq);
-    client.http.request.mockImplementation(httpReq);
+    responses.forEach(response => {
+        httpBackend
+            .when(response.method, response.path)
+            .respond(200, response.data);
+    });
 }
+
+export const emitPromise = (e, k) => new Promise(r => e.once(k, r));

spec/unit/crypto/cross-signing.spec.js

@@ -40,13 +40,14 @@ async function makeTestClient(userInfo, options, keys) {
     options.cryptoCallbacks = Object.assign(
         {}, { getCrossSigningKey, saveCrossSigningKeys }, options.cryptoCallbacks || {},
     );
-    const client = (new TestClient(
+    const testClient = new TestClient(
         userInfo.userId, userInfo.deviceId, undefined, undefined, options,
-    )).client;
+    );
+    const client = testClient.client;
 
     await client.initCrypto();
 
-    return client;
+    return { client, httpBackend: testClient.httpBackend };
 }
 
 describe("Cross Signing", function() {
@@ -60,7 +61,7 @@ describe("Cross Signing", function() {
     });
 
     it("should sign the master key with the device key", async function() {
-        const alice = await makeTestClient(
+        const { client: alice } = await makeTestClient(
             { userId: "@alice:example.com", deviceId: "Osborne2" },
         );
         alice.uploadDeviceSigningKeys = jest.fn(async (auth, keys) => {
@@ -80,7 +81,7 @@ describe("Cross Signing", function() {
     });
 
     it("should abort bootstrap if device signing auth fails", async function() {
-        const alice = await makeTestClient(
+        const { client: alice } = await makeTestClient(
             { userId: "@alice:example.com", deviceId: "Osborne2" },
         );
         alice.uploadDeviceSigningKeys = async (auth, keys) => {
@@ -131,7 +132,7 @@ describe("Cross Signing", function() {
     });
 
     it("should upload a signature when a user is verified", async function() {
-        const alice = await makeTestClient(
+        const { client: alice } = await makeTestClient(
             { userId: "@alice:example.com", deviceId: "Osborne2" },
         );
         alice.uploadDeviceSigningKeys = async () => {};
@@ -161,7 +162,7 @@ describe("Cross Signing", function() {
         await promise;
     });
 
-    it("should get cross-signing keys from sync", async function() {
+    it.skip("should get cross-signing keys from sync", async function() {
         const masterKey = new Uint8Array([
             0xda, 0x5a, 0x27, 0x60, 0xe3, 0x3a, 0xc5, 0x82,
             0x9d, 0x12, 0xc3, 0xbe, 0xe8, 0xaa, 0xc2, 0xef,
@@ -175,7 +176,7 @@ describe("Cross Signing", function() {
             0x34, 0xf2, 0x4b, 0x64, 0x9b, 0x52, 0xf8, 0x5f,
         ]);
 
-        const alice = await makeTestClient(
+        const { client: alice, httpBackend } = await makeTestClient(
             { userId: "@alice:example.com", deviceId: "Osborne2" },
             {
                 cryptoCallbacks: {
@@ -236,6 +237,7 @@ describe("Cross Signing", function() {
 
         // feed sync result that includes master key, ssk, device key
         const responses = [
+            HttpResponse.CAPABILITIES_RESPONSE,
             HttpResponse.PUSH_RULES_RESPONSE,
             {
                 method: "POST",
@@ -311,9 +313,10 @@ describe("Cross Signing", function() {
                 },
             },
         ];
-        setHttpResponses(alice, responses, true, true);
+        setHttpResponses(httpBackend, responses);
 
-        await alice.startClient();
+        alice.startClient();
+        httpBackend.flushAllExpected();
 
         // once ssk is confirmed, device key should be trusted
         await keyChangePromise;
@@ -332,7 +335,7 @@ describe("Cross Signing", function() {
     });
 
     it("should use trust chain to determine device verification", async function() {
-        const alice = await makeTestClient(
+        const { client: alice } = await makeTestClient(
             { userId: "@alice:example.com", deviceId: "Osborne2" },
         );
         alice.uploadDeviceSigningKeys = async () => {};
@@ -415,9 +418,9 @@ describe("Cross Signing", function() {
         expect(bobDeviceTrust2.isTofu()).toBeTruthy();
     });
 
-    it("should trust signatures received from other devices", async function() {
+    it.skip("should trust signatures received from other devices", async function() {
         const aliceKeys = {};
-        const alice = await makeTestClient(
+        const { client: alice, httpBackend } = await makeTestClient(
             { userId: "@alice:example.com", deviceId: "Osborne2" },
             null,
             aliceKeys,
@@ -491,6 +494,7 @@ describe("Cross Signing", function() {
         // - master key signed by her usk (pretend that it was signed by another
         //   of Alice's devices)
         const responses = [
+            HttpResponse.CAPABILITIES_RESPONSE,
             HttpResponse.PUSH_RULES_RESPONSE,
             {
                 method: "POST",
@@ -561,10 +565,10 @@ describe("Cross Signing", function() {
                 },
             },
         ];
-        setHttpResponses(alice, responses);
-
-        await alice.startClient();
+        setHttpResponses(httpBackend, responses);
 
+        alice.startClient();
+        httpBackend.flushAllExpected();
         await keyChangePromise;
 
         // Bob's device key should be trusted
@@ -579,7 +583,7 @@ describe("Cross Signing", function() {
     });
 
     it("should dis-trust an unsigned device", async function() {
-        const alice = await makeTestClient(
+        const { client: alice } = await makeTestClient(
             { userId: "@alice:example.com", deviceId: "Osborne2" },
         );
         alice.uploadDeviceSigningKeys = async () => {};
@@ -648,7 +652,7 @@ describe("Cross Signing", function() {
     });
 
     it("should dis-trust a user when their ssk changes", async function() {
-        const alice = await makeTestClient(
+        const { client: alice } = await makeTestClient(
             { userId: "@alice:example.com", deviceId: "Osborne2" },
         );
         alice.uploadDeviceSigningKeys = async () => {};
@@ -786,7 +790,7 @@ describe("Cross Signing", function() {
     it("should offer to upgrade device verifications to cross-signing", async function() {
         let upgradeResolveFunc;
 
-        const alice = await makeTestClient(
+        const { client: alice } = await makeTestClient(
             { userId: "@alice:example.com", deviceId: "Osborne2" },
             {
                 cryptoCallbacks: {
@@ -798,7 +802,7 @@ describe("Cross Signing", function() {
                 },
             },
         );
-        const bob = await makeTestClient(
+        const { client: bob } = await makeTestClient(
             { userId: "@bob:example.com", deviceId: "Dynabook" },
         );
 

spec/unit/location.spec.ts

@@ -0,0 +1,56 @@
+/*
+Copyright 2022 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 { makeLocationContent } from "../../src/content-helpers";
+import {
+    ASSET_NODE_TYPE,
+    ASSET_TYPE_SELF,
+    LOCATION_EVENT_TYPE,
+    TIMESTAMP_NODE_TYPE,
+} from "../../src/@types/location";
+import { TEXT_NODE_TYPE } from "../../src/@types/extensible_events";
+
+describe("Location", function() {
+    it("should create a valid location with defaults", function() {
+        const loc = makeLocationContent("txt", "geo:foo", 134235435);
+        expect(loc.body).toEqual("txt");
+        expect(loc.msgtype).toEqual("m.location");
+        expect(loc.geo_uri).toEqual("geo:foo");
+        expect(LOCATION_EVENT_TYPE.findIn(loc)).toEqual({
+            uri: "geo:foo",
+            description: undefined,
+        });
+        expect(ASSET_NODE_TYPE.findIn(loc)).toEqual({ type: ASSET_TYPE_SELF });
+        expect(TEXT_NODE_TYPE.findIn(loc)).toEqual("txt");
+        expect(TIMESTAMP_NODE_TYPE.findIn(loc)).toEqual(134235435);
+    });
+
+    it("should create a valid location with explicit properties", function() {
+        const loc = makeLocationContent(
+            "txxt", "geo:bar", 134235436, "desc", "m.something");
+
+        expect(loc.body).toEqual("txxt");
+        expect(loc.msgtype).toEqual("m.location");
+        expect(loc.geo_uri).toEqual("geo:bar");
+        expect(LOCATION_EVENT_TYPE.findIn(loc)).toEqual({
+            uri: "geo:bar",
+            description: "desc",
+        });
+        expect(ASSET_NODE_TYPE.findIn(loc)).toEqual({ type: "m.something" });
+        expect(TEXT_NODE_TYPE.findIn(loc)).toEqual("txxt");
+        expect(TIMESTAMP_NODE_TYPE.findIn(loc)).toEqual(134235436);
+    });
+});

spec/unit/matrix-client.spec.js

@@ -11,8 +11,9 @@ import {
     UNSTABLE_MSC3089_TREE_SUBTYPE,
 } from "../../src/@types/event";
 import { MEGOLM_ALGORITHM } from "../../src/crypto/olmlib";
-import { MatrixEvent } from "../../src/models/event";
+import { EventStatus, MatrixEvent } from "../../src/models/event";
 import { Preset } from "../../src/@types/partials";
+import * as testUtils from "../test-utils";
 
 jest.useFakeTimers();
 
@@ -52,6 +53,12 @@ describe("MatrixClient", function() {
         data: SYNC_DATA,
     };
 
+    const CAPABILITIES_RESPONSE = {
+        method: "GET",
+        path: "/capabilities",
+        data: { capabilities: {} },
+    };
+
     let httpLookups = [
         // items are objects which look like:
         // {
@@ -167,6 +174,7 @@ describe("MatrixClient", function() {
         acceptKeepalives = true;
         pendingLookup = null;
         httpLookups = [];
+        httpLookups.push(CAPABILITIES_RESPONSE);
         httpLookups.push(PUSH_RULES_RESPONSE);
         httpLookups.push(FILTER_RESPONSE);
         httpLookups.push(SYNC_RESPONSE);
@@ -364,9 +372,11 @@ describe("MatrixClient", function() {
     });
 
     it("should not POST /filter if a matching filter already exists", async function() {
-        httpLookups = [];
-        httpLookups.push(PUSH_RULES_RESPONSE);
-        httpLookups.push(SYNC_RESPONSE);
+        httpLookups = [
+            CAPABILITIES_RESPONSE,
+            PUSH_RULES_RESPONSE,
+            SYNC_RESPONSE,
+        ];
         const filterId = "ehfewf";
         store.getFilterIdByName.mockReturnValue(filterId);
         const filter = new Filter(0, filterId);
@@ -447,12 +457,15 @@ describe("MatrixClient", function() {
 
     describe("retryImmediately", function() {
         it("should return false if there is no request waiting", async function() {
+            httpLookups = [];
+            httpLookups.push(CAPABILITIES_RESPONSE);
             await client.startClient();
             expect(client.retryImmediately()).toBe(false);
         });
 
         it("should work on /filter", function(done) {
             httpLookups = [];
+            httpLookups.push(CAPABILITIES_RESPONSE);
             httpLookups.push(PUSH_RULES_RESPONSE);
             httpLookups.push({
                 method: "POST", path: FILTER_PATH, error: { errcode: "NOPE_NOPE_NOPE" },
@@ -503,6 +516,7 @@ describe("MatrixClient", function() {
 
         it("should work on /pushrules", function(done) {
             httpLookups = [];
+            httpLookups.push(CAPABILITIES_RESPONSE);
             httpLookups.push({
                 method: "GET", path: "/pushrules/", error: { errcode: "NOPE_NOPE_NOPE" },
             });
@@ -559,6 +573,7 @@ describe("MatrixClient", function() {
         it("should transition null -> ERROR after a failed /filter", function(done) {
             const expectedStates = [];
             httpLookups = [];
+            httpLookups.push(CAPABILITIES_RESPONSE);
             httpLookups.push(PUSH_RULES_RESPONSE);
             httpLookups.push({
                 method: "POST", path: FILTER_PATH, error: { errcode: "NOPE_NOPE_NOPE" },
@@ -573,6 +588,7 @@ describe("MatrixClient", function() {
             const expectedStates = [];
             acceptKeepalives = false;
             httpLookups = [];
+            httpLookups.push(CAPABILITIES_RESPONSE);
             httpLookups.push(PUSH_RULES_RESPONSE);
             httpLookups.push(FILTER_RESPONSE);
             httpLookups.push({
@@ -697,7 +713,8 @@ describe("MatrixClient", function() {
 
     describe("guest rooms", function() {
         it("should only do /sync calls (without filter/pushrules)", function(done) {
-            httpLookups = []; // no /pushrules or /filter
+            httpLookups = []; // no /pushrules or /filterw
+            httpLookups.push(CAPABILITIES_RESPONSE);
             httpLookups.push({
                 method: "GET",
                 path: "/sync",
@@ -728,4 +745,207 @@ describe("MatrixClient", function() {
             expect(httpLookups.length).toEqual(0);
         });
     });
+
+    describe("sendEvent", () => {
+        const roomId = "!room:example.org";
+        const body = "This is the body";
+        const content = { body };
+
+        it("overload without threadId works", async () => {
+            const eventId = "$eventId:example.org";
+            const txnId = client.makeTxnId();
+            httpLookups = [{
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${txnId}`,
+                data: { event_id: eventId },
+                expectBody: content,
+            }];
+
+            await client.sendEvent(roomId, EventType.RoomMessage, content, txnId);
+        });
+
+        it("overload with null threadId works", async () => {
+            const eventId = "$eventId:example.org";
+            const txnId = client.makeTxnId();
+            httpLookups = [{
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${txnId}`,
+                data: { event_id: eventId },
+                expectBody: content,
+            }];
+
+            await client.sendEvent(roomId, null, EventType.RoomMessage, content, txnId);
+        });
+
+        it("overload with threadId works", async () => {
+            const eventId = "$eventId:example.org";
+            const txnId = client.makeTxnId();
+            httpLookups = [{
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/send/m.room.message/${txnId}`,
+                data: { event_id: eventId },
+                expectBody: content,
+            }];
+
+            await client.sendEvent(roomId, "$threadId:server", EventType.RoomMessage, content, txnId);
+        });
+    });
+
+    describe("redactEvent", () => {
+        const roomId = "!room:example.org";
+        const mockRoom = {
+            getMyMembership: () => "join",
+            currentState: {
+                getStateEvents: (eventType, stateKey) => {
+                    if (eventType === EventType.RoomEncryption) {
+                        expect(stateKey).toEqual("");
+                        return new MatrixEvent({ content: {} });
+                    } else {
+                        throw new Error("Unexpected event type or state key");
+                    }
+                },
+            },
+            threads: {
+                get: jest.fn(),
+            },
+            addPendingEvent: jest.fn(),
+            updatePendingEvent: jest.fn(),
+        };
+
+        beforeEach(() => {
+            client.getRoom = (getRoomId) => {
+                expect(getRoomId).toEqual(roomId);
+                return mockRoom;
+            };
+        });
+
+        it("overload without threadId works", async () => {
+            const eventId = "$eventId:example.org";
+            const txnId = client.makeTxnId();
+            httpLookups = [{
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/redact/${encodeURIComponent(eventId)}/${txnId}`,
+                data: { event_id: eventId },
+            }];
+
+            await client.redactEvent(roomId, eventId, txnId);
+        });
+
+        it("overload with null threadId works", async () => {
+            const eventId = "$eventId:example.org";
+            const txnId = client.makeTxnId();
+            httpLookups = [{
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/redact/${encodeURIComponent(eventId)}/${txnId}`,
+                data: { event_id: eventId },
+            }];
+
+            await client.redactEvent(roomId, null, eventId, txnId);
+        });
+
+        it("overload with threadId works", async () => {
+            const eventId = "$eventId:example.org";
+            const txnId = client.makeTxnId();
+            httpLookups = [{
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/redact/${encodeURIComponent(eventId)}/${txnId}`,
+                data: { event_id: eventId },
+            }];
+
+            await client.redactEvent(roomId, "$threadId:server", eventId, txnId);
+        });
+
+        it("does not get wrongly encrypted", async () => {
+            const eventId = "$eventId:example.org";
+            const txnId = client.makeTxnId();
+            const reason = "This is the redaction reason";
+            httpLookups = [{
+                method: "PUT",
+                path: `/rooms/${encodeURIComponent(roomId)}/redact/${encodeURIComponent(eventId)}/${txnId}`,
+                expectBody: { reason }, // NOT ENCRYPTED
+                data: { event_id: eventId },
+            }];
+
+            await client.redactEvent(roomId, eventId, txnId, { reason });
+        });
+    });
+
+    describe("cancelPendingEvent", () => {
+        const roomId = "!room:server";
+        const txnId = "m12345";
+
+        const mockRoom = {
+            getMyMembership: () => "join",
+            updatePendingEvent: (event, status) => event.setStatus(status),
+            currentState: {
+                getStateEvents: (eventType, stateKey) => {
+                    if (eventType === EventType.RoomCreate) {
+                        expect(stateKey).toEqual("");
+                        return new MatrixEvent({
+                            content: {
+                                [RoomCreateTypeField]: RoomType.Space,
+                            },
+                        });
+                    } else if (eventType === EventType.RoomEncryption) {
+                        expect(stateKey).toEqual("");
+                        return new MatrixEvent({ content: {} });
+                    } else {
+                        throw new Error("Unexpected event type or state key");
+                    }
+                },
+            },
+        };
+
+        let event;
+        beforeEach(async () => {
+            event = new MatrixEvent({
+                event_id: "~" + roomId + ":" + txnId,
+                user_id: client.credentials.userId,
+                sender: client.credentials.userId,
+                room_id: roomId,
+                origin_server_ts: new Date().getTime(),
+            });
+            event.setTxnId(txnId);
+
+            client.getRoom = (getRoomId) => {
+                expect(getRoomId).toEqual(roomId);
+                return mockRoom;
+            };
+            client.crypto = { // mock crypto
+                encryptEvent: (event, room) => new Promise(() => {}),
+            };
+        });
+
+        function assertCancelled() {
+            expect(event.status).toBe(EventStatus.CANCELLED);
+            expect(client.scheduler.removeEventFromQueue(event)).toBeFalsy();
+            expect(httpLookups.filter(h => h.path.includes("/send/")).length).toBe(0);
+        }
+
+        it("should cancel an event which is queued", () => {
+            event.setStatus(EventStatus.QUEUED);
+            client.scheduler.queueEvent(event);
+            client.cancelPendingEvent(event);
+            assertCancelled();
+        });
+
+        it("should cancel an event which is encrypting", async () => {
+            client.encryptAndSendEvent(null, event);
+            await testUtils.emitPromise(event, "Event.status");
+            client.cancelPendingEvent(event);
+            assertCancelled();
+        });
+
+        it("should cancel an event which is not sent", () => {
+            event.setStatus(EventStatus.NOT_SENT);
+            client.cancelPendingEvent(event);
+            assertCancelled();
+        });
+
+        it("should error when given any other event status", () => {
+            event.setStatus(EventStatus.SENDING);
+            expect(() => client.cancelPendingEvent(event)).toThrow("cannot cancel an event with status sending");
+            expect(event.status).toBe(EventStatus.SENDING);
+        });
+    });
 });

spec/unit/models/MSC3089Branch.spec.ts

@@ -312,7 +312,7 @@ describe("MSC3089Branch", () => {
         } as MatrixEvent);
 
         const events = [await branch.getFileEvent(), await branch2.getFileEvent(), {
-            replacingEventId: () => null,
+            replacingEventId: (): string => null,
             getId: () => "$unknown",
         }];
         staticRoom.getLiveTimeline = () => ({ getEvents: () => events }) as EventTimeline;

spec/unit/room-state.spec.js

@@ -120,7 +120,7 @@ describe("RoomState", function() {
         it("should return a single MatrixEvent if a state_key was specified",
         function() {
             const event = state.getStateEvents("m.room.member", userA);
-            expect(event.getContent()).toEqual({
+            expect(event.getContent()).toMatchObject({
                 membership: "join",
             });
         });

spec/unit/room.spec.js

@@ -622,6 +622,11 @@ describe("Room", function() {
                 }, event: true,
             })]);
         };
+        const setAlias = function(alias) {
+            room.addLiveEvents([utils.mkEvent({
+                type: "m.room.canonical_alias", room: roomId, skey: "", content: { alias }, event: true,
+            })]);
+        };
         const setRoomName = function(name) {
             room.addLiveEvents([utils.mkEvent({
                 type: "m.room.name", room: roomId, user: userA, content: {
@@ -857,7 +862,7 @@ describe("Room", function() {
             "(invite join_rules) rooms if a room name doesn't exist.", function() {
                 const alias = "#room_alias:here";
                 setJoinRule("invite");
-                setAltAliases([alias, "#another:here"]);
+                setAlias(alias);
                 room.recalculate();
                 const name = room.name;
                 expect(name).toEqual(alias);
@@ -867,12 +872,20 @@ describe("Room", function() {
             "(public join_rules) rooms if a room name doesn't exist.", function() {
                 const alias = "#room_alias:here";
                 setJoinRule("public");
-                setAltAliases([alias, "#another:here"]);
+                setAlias(alias);
                 room.recalculate();
                 const name = room.name;
                 expect(name).toEqual(alias);
             });
 
+            it("should not show alt aliases if a room name does not exist", () => {
+                const alias = "#room_alias:here";
+                setAltAliases([alias, "#another:here"]);
+                room.recalculate();
+                const name = room.name;
+                expect(name).not.toEqual(alias);
+            });
+
             it("should show the room name if one exists for private " +
             "(invite join_rules) rooms.", function() {
                 const roomName = "A mighty name indeed";
@@ -1130,6 +1143,51 @@ describe("Room", function() {
                 ]));
                 expect(room.getEventReadUpTo(userB)).toEqual(events[2].getId());
             });
+
+            it("should prioritise the most recent event even if it is synthetic", () => {
+                const events = [
+                    utils.mkMessage({
+                        room: roomId, user: userA, msg: "1111",
+                        event: true,
+                    }),
+                    utils.mkMessage({
+                        room: roomId, user: userA, msg: "2222",
+                        event: true,
+                    }),
+                    utils.mkMessage({
+                        room: roomId, user: userA, msg: "3333",
+                        event: true,
+                    }),
+                ];
+
+                room.addLiveEvents(events);
+                const ts = 13787898424;
+
+                // check it initialises correctly
+                room.addReceipt(mkReceipt(roomId, [
+                    mkRecord(events[0].getId(), "m.read", userB, ts),
+                ]));
+                expect(room.getEventReadUpTo(userB)).toEqual(events[0].getId());
+
+                // 2>0, so it should move forward
+                room.addReceipt(mkReceipt(roomId, [
+                    mkRecord(events[2].getId(), "m.read", userB, ts),
+                ]), true);
+                expect(room.getEventReadUpTo(userB)).toEqual(events[2].getId());
+                expect(room.getReceiptsForEvent(events[2])).toEqual([
+                    { data: { ts }, type: "m.read", userId: userB },
+                ]);
+
+                // 1<2, so it should stay put
+                room.addReceipt(mkReceipt(roomId, [
+                    mkRecord(events[1].getId(), "m.read", userB, ts),
+                ]));
+                expect(room.getEventReadUpTo(userB)).toEqual(events[2].getId());
+                expect(room.getEventReadUpTo(userB, true)).toEqual(events[1].getId());
+                expect(room.getReceiptsForEvent(events[2])).toEqual([
+                    { data: { ts }, type: "m.read", userId: userB },
+                ]);
+            });
         });
 
         describe("getUsersReadUpTo", function() {
@@ -1448,7 +1506,7 @@ describe("Room", function() {
     describe("maySendMessage", function() {
         it("should return false if synced membership not join",
         function() {
-            const room = new Room(roomId, null, userA);
+            const room = new Room(roomId, { isRoomEncrypted: () => false }, userA);
             room.updateMyMembership("invite");
             expect(room.maySendMessage()).toEqual(false);
             room.updateMyMembership("leave");

src/@types/event.ts

@@ -177,6 +177,16 @@ export const UNSTABLE_ELEMENT_FUNCTIONAL_USERS = new UnstableValue(
     "io.element.functional_members",
     "io.element.functional_members");
 
+/**
+ * A type of message that affects visibility of a message,
+ * as per https://github.com/matrix-org/matrix-doc/pull/3531
+ *
+ * @experimental
+ */
+export const EVENT_VISIBILITY_CHANGE_TYPE = new UnstableValue(
+    "m.visibility",
+    "org.matrix.msc3531.visibility");
+
 export interface IEncryptedFile {
     url: string;
     mimetype?: string;

src/@types/extensible_events.ts

@@ -14,13 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-// TODO: Merge this with sync.js once converted
+// Types for MSC1767: Extensible events in Matrix
 
-export enum SyncState {
-    Error = "ERROR",
-    Prepared = "PREPARED",
-    Stopped = "STOPPED",
-    Syncing = "SYNCING",
-    Catchup = "CATCHUP",
-    Reconnecting = "RECONNECTING",
-}
+import { UnstableValue } from "../NamespacedValue";
+
+export const TEXT_NODE_TYPE = new UnstableValue("m.text", "org.matrix.msc1767.text");

src/@types/global.d.ts

@@ -62,12 +62,6 @@ declare global {
         };
     }
 
-    interface HTMLAudioElement {
-        // sinkId & setSinkId are experimental and typescript doesn't know about them
-        sinkId: string;
-        setSinkId(outputId: string);
-    }
-
     interface DummyInterfaceWeShouldntBeUsingThis {}
 
     interface Navigator {

src/@types/location.ts

@@ -0,0 +1,68 @@
+/*
+Copyright 2021 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.
+*/
+
+// Types for MSC3488 - m.location: Extending events with location data
+
+import { UnstableValue } from "../NamespacedValue";
+import { IContent } from "../models/event";
+import { TEXT_NODE_TYPE } from "./extensible_events";
+
+export const LOCATION_EVENT_TYPE = new UnstableValue(
+    "m.location", "org.matrix.msc3488.location");
+
+export const ASSET_NODE_TYPE = new UnstableValue("m.asset", "org.matrix.msc3488.asset");
+
+export const TIMESTAMP_NODE_TYPE = new UnstableValue("m.ts", "org.matrix.msc3488.ts");
+
+export const ASSET_TYPE_SELF = "m.self";
+
+/* From the spec at:
+ * https://github.com/matrix-org/matrix-doc/blob/matthew/location/proposals/3488-location.md
+{
+    "type": "m.room.message",
+    "content": {
+        "body": "Matthew was at geo:51.5008,0.1247;u=35 as of Sat Nov 13 18:50:58 2021",
+        "msgtype": "m.location",
+        "geo_uri": "geo:51.5008,0.1247;u=35",
+        "m.location": {
+            "uri": "geo:51.5008,0.1247;u=35",
+            "description": "Matthew's whereabouts",
+        },
+        "m.asset": {
+            "type": "m.self"
+        },
+        "m.text": "Matthew was at geo:51.5008,0.1247;u=35 as of Sat Nov 13 18:50:58 2021",
+        "m.ts": 1636829458432,
+    }
+}
+*/
+
+/* eslint-disable camelcase */
+export interface ILocationContent extends IContent {
+    body: string;
+    msgtype: string;
+    geo_uri: string;
+    [LOCATION_EVENT_TYPE.name]: {
+        uri: string;
+        description?: string;
+    };
+    [ASSET_NODE_TYPE.name]: {
+        type: string;
+    };
+    [TEXT_NODE_TYPE.name]: string;
+    [TIMESTAMP_NODE_TYPE.name]: number;
+}
+/* eslint-enable camelcase */

src/@types/partials.ts

@@ -82,3 +82,12 @@ export enum HistoryVisibility {
     Shared = "shared",
     WorldReadable = "world_readable",
 }
+
+export interface IUsageLimit {
+    // "hs_disabled" is NOT a specced string, but is used in Synapse
+    // This is tracked over at https://github.com/matrix-org/synapse/issues/9237
+    // eslint-disable-next-line camelcase
+    limit_type: "monthly_active_user" | "hs_disabled" | string;
+    // eslint-disable-next-line camelcase
+    admin_contact?: string;
+}

src/@types/requests.ts

@@ -19,6 +19,7 @@ import { IContent, IEvent } from "../models/event";
 import { Preset, Visibility } from "./partials";
 import { SearchKey } from "./search";
 import { IRoomEventFilter } from "../filter";
+import { Direction } from "../models/event-timeline";
 
 // allow camelcase as these are things that go onto the wire
 /* eslint-disable camelcase */
@@ -144,6 +145,7 @@ export interface IRelationsRequestOpts {
     from?: string;
     to?: string;
     limit?: number;
+    direction?: Direction;
 }
 
 export interface IRelationsResponse {

src/@types/spaces.ts

@@ -44,7 +44,6 @@ export interface ISpaceSummaryEvent {
 }
 
 export interface IHierarchyRelation extends IStrippedState {
-    room_id: string;
     origin_server_ts: number;
     content: {
         order?: string;

src/content-helpers.ts

@@ -1,6 +1,5 @@
 /*
-Copyright 2018 New Vector Ltd
-Copyright 2018 - 2021 The Matrix.org Foundation C.I.C.
+Copyright 2018 - 2022 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.
@@ -18,6 +17,14 @@ limitations under the License.
 /** @module ContentHelpers */
 
 import { MsgType } from "./@types/event";
+import { TEXT_NODE_TYPE } from "./@types/extensible_events";
+import {
+    ASSET_NODE_TYPE,
+    ASSET_TYPE_SELF,
+    ILocationContent,
+    LOCATION_EVENT_TYPE,
+    TIMESTAMP_NODE_TYPE,
+} from "./@types/location";
 
 /**
  * Generates the content for a HTML Message event
@@ -99,3 +106,36 @@ export function makeEmoteMessage(body: string) {
         body: body,
     };
 }
+
+/**
+ * Generates the content for a Location event
+ * @param text a text for of our location
+ * @param uri a geo:// uri for the location
+ * @param ts the timestamp when the location was correct (milliseconds since
+ *           the UNIX epoch)
+ * @param description the (optional) label for this location on the map
+ * @param asset_type the (optional) asset type of this location e.g. "m.self"
+ */
+export function makeLocationContent(
+    text: string,
+    uri: string,
+    ts: number,
+    description?: string,
+    assetType?: string,
+): ILocationContent {
+    return {
+        "body": text,
+        "msgtype": MsgType.Location,
+        "geo_uri": uri,
+        [LOCATION_EVENT_TYPE.name]: {
+            uri,
+            description,
+        },
+        [ASSET_NODE_TYPE.name]: {
+            type: assetType ?? ASSET_TYPE_SELF,
+        },
+        [TEXT_NODE_TYPE.name]: text,
+        [TIMESTAMP_NODE_TYPE.name]: ts,
+        // TODO: MSC1767 fallbacks m.image thumbnail
+    };
+}

src/crypto/CrossSigning.ts

@@ -33,6 +33,7 @@ import { OlmDevice } from "./OlmDevice";
 import { ICryptoCallbacks } from "../matrix";
 import { ISignatures } from "../@types/signed";
 import { CryptoStore } from "./store/base";
+import { ISecretStorageKeyInfo } from "./api";
 
 const KEY_REQUEST_TIMEOUT_MS = 1000 * 60;
 
@@ -175,7 +176,7 @@ export class CrossSigningInfo extends EventEmitter {
         // check what SSSS keys have encrypted the master key (if any)
         const stored = await secretStorage.isStored("m.cross_signing.master", false) || {};
         // then check which of those SSSS keys have also encrypted the SSK and USK
-        function intersect(s) {
+        function intersect(s: Record<string, ISecretStorageKeyInfo>) {
             for (const k of Object.keys(stored)) {
                 if (!s[k]) {
                     delete stored[k];

src/crypto/DeviceList.ts

@@ -28,7 +28,7 @@ import { CrossSigningInfo, ICrossSigningInfo } from './CrossSigning';
 import * as olmlib from './olmlib';
 import { IndexedDBCryptoStore } from './store/indexeddb-crypto-store';
 import { chunkPromises, defer, IDeferred, sleep } from '../utils';
-import { MatrixClient } from "../client";
+import { IDownloadKeyResult, MatrixClient } from "../client";
 import { OlmDevice } from "./OlmDevice";
 import { CryptoStore } from "./store/base";
 
@@ -756,17 +756,21 @@ class DeviceListUpdateSerialiser {
             opts.token = this.syncToken;
         }
 
-        const factories = [];
+        const factories: Array<() => Promise<IDownloadKeyResult>> = [];
         for (let i = 0; i < downloadUsers.length; i += this.deviceList.keyDownloadChunkSize) {
             const userSlice = downloadUsers.slice(i, i + this.deviceList.keyDownloadChunkSize);
             factories.push(() => this.baseApis.downloadKeysForUsers(userSlice, opts));
         }
 
-        chunkPromises(factories, 3).then(async (responses: any[]) => {
-            const dk = Object.assign({}, ...(responses.map(res => res.device_keys || {})));
-            const masterKeys = Object.assign({}, ...(responses.map(res => res.master_keys || {})));
-            const ssks = Object.assign({}, ...(responses.map(res => res.self_signing_keys || {})));
-            const usks = Object.assign({}, ...(responses.map(res => res.user_signing_keys || {})));
+        chunkPromises(factories, 3).then(async (responses: IDownloadKeyResult[]) => {
+            const dk: IDownloadKeyResult["device_keys"]
+                = Object.assign({}, ...(responses.map(res => res.device_keys || {})));
+            const masterKeys: IDownloadKeyResult["master_keys"]
+                = Object.assign({}, ...(responses.map(res => res.master_keys || {})));
+            const ssks: IDownloadKeyResult["self_signing_keys"]
+                = Object.assign({}, ...(responses.map(res => res.self_signing_keys || {})));
+            const usks: IDownloadKeyResult["user_signing_keys"]
+                = Object.assign({}, ...(responses.map(res => res.user_signing_keys || {})));
 
             // yield to other things that want to execute in between users, to
             // avoid wedging the CPU
@@ -811,8 +815,12 @@ class DeviceListUpdateSerialiser {
 
     private async processQueryResponseForUser(
         userId: string,
-        dkResponse: object,
-        crossSigningResponse: any, // TODO types
+        dkResponse: IDownloadKeyResult["device_keys"]["user_id"],
+        crossSigningResponse: {
+            master: IDownloadKeyResult["master_keys"]["user_id"];
+            self_signing: IDownloadKeyResult["master_keys"]["user_id"]; // eslint-disable-line camelcase
+            user_signing: IDownloadKeyResult["user_signing_keys"]["user_id"]; // eslint-disable-line camelcase
+        },
     ): Promise<void> {
         logger.log('got device keys for ' + userId + ':', dkResponse);
         logger.log('got cross-signing keys for ' + userId + ':', crossSigningResponse);
@@ -869,7 +877,7 @@ async function updateStoredDeviceKeysForUser(
     olmDevice: OlmDevice,
     userId: string,
     userStore: Record<string, DeviceInfo>,
-    userResult: object,
+    userResult: IDownloadKeyResult["device_keys"]["user_id"],
     localUserId: string,
     localDeviceId: string,
 ): Promise<boolean> {

src/crypto/EncryptionSetup.ts

@@ -20,15 +20,9 @@ import { logger } from "../logger";
 import { MatrixEvent } from "../models/event";
 import { createCryptoStoreCacheCallbacks, ICacheCallbacks } from "./CrossSigning";
 import { IndexedDBCryptoStore } from './store/indexeddb-crypto-store';
-import { PREFIX_UNSTABLE } from "../http-api";
+import { Method, PREFIX_UNSTABLE } from "../http-api";
 import { Crypto, IBootstrapCrossSigningOpts } from "./index";
-import {
-    CrossSigningKeys,
-    ICrossSigningKey,
-    ICryptoCallbacks,
-    ISignedKey,
-    KeySignatures,
-} from "../matrix";
+import { CrossSigningKeys, ICrossSigningKey, ICryptoCallbacks, ISignedKey, KeySignatures } from "../matrix";
 import { ISecretStorageKeyInfo } from "./api";
 import { IKeyBackupInfo } from "./keybackup";
 
@@ -239,7 +233,7 @@ export class EncryptionSetupOperation {
                 // Sign the backup with the cross signing key so the key backup can
                 // be trusted via cross-signing.
                 await baseApis.http.authedRequest(
-                    undefined, "PUT", "/room_keys/version/" + this.keyBackupInfo.version,
+                    undefined, Method.Put, "/room_keys/version/" + this.keyBackupInfo.version,
                     undefined, {
                         algorithm: this.keyBackupInfo.algorithm,
                         auth_data: this.keyBackupInfo.auth_data,
@@ -249,7 +243,7 @@ export class EncryptionSetupOperation {
             } else {
                 // add new key backup
                 await baseApis.http.authedRequest(
-                    undefined, "POST", "/room_keys/version",
+                    undefined, Method.Post, "/room_keys/version",
                     undefined, this.keyBackupInfo,
                     { prefix: PREFIX_UNSTABLE },
                 );

src/crypto/SecretStorage.ts

@@ -83,7 +83,7 @@ export class SecretStorage {
         private readonly baseApis?: MatrixClient,
     ) {}
 
-    public async getDefaultKeyId(): Promise<string> {
+    public async getDefaultKeyId(): Promise<string | null> {
         const defaultKey = await this.accountDataAdapter.getAccountDataFromServer<{ key: string }>(
             'm.secret_storage.default_key',
         );
@@ -345,7 +345,7 @@ export class SecretStorage {
      *     with, or null if it is not present or not encrypted with a trusted
      *     key
      */
-    public async isStored(name: string, checkKey: boolean): Promise<Record<string, ISecretStorageKeyInfo>> {
+    public async isStored(name: string, checkKey: boolean): Promise<Record<string, ISecretStorageKeyInfo> | null> {
         // check if secret exists
         const secretInfo = await this.accountDataAdapter.getAccountDataFromServer<ISecretInfo>(name);
         if (!secretInfo) return null;

src/crypto/algorithms/megolm.ts

@@ -1114,8 +1114,8 @@ class MegolmEncryption extends EncryptionAlgorithm {
     private checkForUnknownDevices(devicesInRoom: DeviceInfoMap): void {
         const unknownDevices: Record<string, Record<string, DeviceInfo>> = {};
 
-        Object.keys(devicesInRoom).forEach((userId)=>{
-            Object.keys(devicesInRoom[userId]).forEach((deviceId)=>{
+        Object.keys(devicesInRoom).forEach((userId) => {
+            Object.keys(devicesInRoom[userId]).forEach((deviceId) => {
                 const device = devicesInRoom[userId][deviceId];
                 if (device.isUnverified() && !device.isKnown()) {
                     if (!unknownDevices[userId]) {

src/crypto/backup.ts

@@ -33,6 +33,7 @@ import { encryptAES, decryptAES, calculateKeyCheck } from './aes';
 import { getCrypto } from '../utils';
 import { ICurve25519AuthData, IAes256AuthData, IKeyBackupInfo, IKeyBackupSession } from "./keybackup";
 import { UnstableValue } from "../NamespacedValue";
+import { IMegolmSessionData } from "./index";
 
 const KEY_BACKUP_KEYS_PER_REQUEST = 200;
 
@@ -87,7 +88,7 @@ interface BackupAlgorithmClass {
 interface BackupAlgorithm {
     untrusted: boolean;
     encryptSession(data: Record<string, any>): Promise<any>;
-    decryptSessions(ciphertexts: Record<string, IKeyBackupSession>): Promise<Record<string, any>[]>;
+    decryptSessions(ciphertexts: Record<string, IKeyBackupSession>): Promise<IMegolmSessionData[]>;
     authData: AuthData;
     keyMatches(key: ArrayLike<number>): Promise<boolean>;
     free(): void;
@@ -185,7 +186,6 @@ export class BackupManager {
     public async prepareKeyBackupVersion(
         key?: string | Uint8Array | null,
         algorithm?: string | undefined,
-        // eslint-disable-next-line camelcase
     ): Promise<IPreparedKeyBackupVersion> {
         const Algorithm = algorithm ? algorithmsByName[algorithm] : DefaultAlgorithm;
         if (!Algorithm) {
@@ -300,7 +300,7 @@ export class BackupManager {
         const ret = {
             usable: false,
             trusted_locally: false,
-            sigs: [],
+            sigs: [] as SigInfo[],
         };
 
         if (
@@ -320,7 +320,7 @@ export class BackupManager {
             ret.trusted_locally = true;
         }
 
-        const mySigs = backupInfo.auth_data.signatures[this.baseApis.getUserId()] || [];
+        const mySigs = backupInfo.auth_data.signatures[this.baseApis.getUserId()] || {};
 
         for (const keyId of Object.keys(mySigs)) {
             const keyIdParts = keyId.split(':');
@@ -645,9 +645,7 @@ export class Curve25519 implements BackupAlgorithm {
         return this.publicKey.encrypt(JSON.stringify(plainText));
     }
 
-    public async decryptSessions(
-        sessions: Record<string, IKeyBackupSession>,
-    ): Promise<Record<string, any>[]> {
+    public async decryptSessions(sessions: Record<string, IKeyBackupSession>): Promise<IMegolmSessionData[]> {
         const privKey = await this.getKey();
         const decryption = new global.Olm.PkDecryption();
         try {
@@ -658,7 +656,7 @@ export class Curve25519 implements BackupAlgorithm {
                 throw { errcode: MatrixClient.RESTORE_BACKUP_ERROR_BAD_KEY };
             }
 
-            const keys = [];
+            const keys: IMegolmSessionData[] = [];
 
             for (const [sessionId, sessionData] of Object.entries(sessions)) {
                 try {
@@ -777,8 +775,8 @@ export class Aes256 implements BackupAlgorithm {
         return await encryptAES(JSON.stringify(plainText), this.key, data.session_id);
     }
 
-    async decryptSessions(sessions: Record<string, IKeyBackupSession>): Promise<Record<string, any>[]> {
-        const keys = [];
+    async decryptSessions(sessions: Record<string, IKeyBackupSession>): Promise<IMegolmSessionData[]> {
+        const keys: IMegolmSessionData[] = [];
 
         for (const [sessionId, sessionData] of Object.entries(sessions)) {
             try {

src/crypto/dehydration.ts

@@ -22,9 +22,8 @@ import { decryptAES, encryptAES } from './aes';
 import { logger } from '../logger';
 import { ISecretStorageKeyInfo } from "./api";
 import { Crypto } from "./index";
-
-// FIXME: these types should eventually go in a different file
-type Signatures = Record<string, Record<string, string>>;
+import { Method } from "../http-api";
+import { ISignatures } from "../@types/signed";
 
 export interface IDehydratedDevice {
     device_id: string; // eslint-disable-line camelcase
@@ -43,13 +42,13 @@ export interface IDeviceKeys {
     device_id: string; // eslint-disable-line camelcase
     user_id: string; // eslint-disable-line camelcase
     keys: Record<string, string>;
-    signatures?: Signatures;
+    signatures?: ISignatures;
 }
 
 export interface IOneTimeKey {
     key: string;
     fallback?: boolean;
-    signatures?: Signatures;
+    signatures?: ISignatures;
 }
 
 export const DEHYDRATION_ALGORITHM = "org.matrix.msc2697.v1.olm.libolm_pickle";
@@ -207,9 +206,10 @@ export class DehydrationManager {
             }
 
             logger.log("Uploading account to server");
-            const dehydrateResult = await this.crypto.baseApis.http.authedRequest(
+            // eslint-disable-next-line camelcase
+            const dehydrateResult = await this.crypto.baseApis.http.authedRequest<{ device_id: string }>(
                 undefined,
-                "PUT",
+                Method.Put,
                 "/dehydrated_device",
                 undefined,
                 {
@@ -244,7 +244,7 @@ export class DehydrationManager {
             }
 
             logger.log("Preparing one-time keys");
-            const oneTimeKeys = {};
+            const oneTimeKeys: Record<string, IOneTimeKey> = {};
             for (const [keyId, key] of Object.entries(otks.curve25519)) {
                 const k: IOneTimeKey = { key };
                 const signature = account.sign(anotherjson.stringify(k));
@@ -272,7 +272,7 @@ export class DehydrationManager {
             logger.log("Uploading keys to server");
             await this.crypto.baseApis.http.authedRequest(
                 undefined,
-                "POST",
+                Method.Post,
                 "/keys/upload/" + encodeURI(deviceId),
                 undefined,
                 {

src/crypto/index.ts

@@ -179,6 +179,13 @@ export interface IEventDecryptionResult {
     untrusted?: boolean;
 }
 
+export interface IRequestsMap {
+    getRequest(event: MatrixEvent): VerificationRequest;
+    getRequestByChannel(channel: IVerificationChannel): VerificationRequest;
+    setRequest(event: MatrixEvent, request: VerificationRequest): void;
+    setRequestByChannel(channel: IVerificationChannel, request: VerificationRequest): void;
+}
+
 export class Crypto extends EventEmitter {
     /**
      * @return {string} The version of Olm.
@@ -808,7 +815,7 @@ export class Crypto extends EventEmitter {
             }
         };
 
-        const signKeyBackupWithCrossSigning = async (keyBackupAuthData) => {
+        const signKeyBackupWithCrossSigning = async (keyBackupAuthData: IKeyBackupInfo["auth_data"]) => {
             if (
                 this.crossSigningInfo.getId() &&
                 await this.crossSigningInfo.isStoredInKeyCache("master")
@@ -1017,7 +1024,7 @@ export class Crypto extends EventEmitter {
     public isSecretStored(
         name: string,
         checkKey?: boolean,
-    ): Promise<Record<string, ISecretStorageKeyInfo>> {
+    ): Promise<Record<string, ISecretStorageKeyInfo> | null> {
         return this.secretStorage.isStored(name, checkKey);
     }
 
@@ -1028,7 +1035,7 @@ export class Crypto extends EventEmitter {
         return this.secretStorage.request(name, devices);
     }
 
-    public getDefaultSecretStorageKeyId(): Promise<string> {
+    public getDefaultSecretStorageKeyId(): Promise<string | null> {
         return this.secretStorage.getDefaultKeyId();
     }
 
@@ -1148,7 +1155,7 @@ export class Crypto extends EventEmitter {
         const signedDevice = await this.crossSigningInfo.signDevice(this.userId, device);
         logger.info(`Starting background key sig upload for ${this.deviceId}`);
 
-        const upload = ({ shouldEmit }) => {
+        const upload = ({ shouldEmit = false }) => {
             return this.baseApis.uploadKeySignatures({
                 [this.userId]: {
                     [this.deviceId]: signedDevice,
@@ -1184,7 +1191,7 @@ export class Crypto extends EventEmitter {
 
             // Check all users for signatures if upgrade callback present
             // FIXME: do this in batches
-            const users = {};
+            const users: Record<string, IDeviceVerificationUpgrade> = {};
             for (const [userId, crossSigningInfo]
                 of Object.entries(this.deviceList.crossSigningInfo)) {
                 const upgradeInfo = await this.checkForDeviceVerificationUpgrade(
@@ -1482,7 +1489,7 @@ export class Crypto extends EventEmitter {
             !crossSigningPrivateKeys.has("user_signing")
         );
 
-        const keySignatures = {};
+        const keySignatures: Record<string, ISignedKey> = {};
 
         if (selfSigningChanged) {
             logger.info("Got new self-signing key", newCrossSigning.getId("self_signing"));
@@ -1537,7 +1544,7 @@ export class Crypto extends EventEmitter {
             // We may have existing signatures from deleted devices, which will cause
             // the entire upload to fail.
             keySignatures[this.crossSigningInfo.getId()] = Object.assign(
-                {},
+                {} as ISignedKey,
                 masterKey,
                 {
                     signatures: {
@@ -1551,7 +1558,7 @@ export class Crypto extends EventEmitter {
 
         const keysToUpload = Object.keys(keySignatures);
         if (keysToUpload.length) {
-            const upload = ({ shouldEmit }) => {
+            const upload = ({ shouldEmit = false }) => {
                 logger.info(`Starting background key sig upload for ${keysToUpload}`);
                 return this.baseApis.uploadKeySignatures({ [this.userId]: keySignatures })
                     .then((response) => {
@@ -1927,7 +1934,7 @@ export class Crypto extends EventEmitter {
         }
 
         const oneTimeKeys = await this.olmDevice.getOneTimeKeys();
-        const oneTimeJson = {};
+        const oneTimeJson: Record<string, { key: string }> = {};
 
         for (const keyId in oneTimeKeys.curve25519) {
             if (oneTimeKeys.curve25519.hasOwnProperty(keyId)) {
@@ -2076,7 +2083,7 @@ export class Crypto extends EventEmitter {
                 );
                 const device = await this.crossSigningInfo.signUser(xsk);
                 if (device) {
-                    const upload = async ({ shouldEmit }) => {
+                    const upload = async ({ shouldEmit = false }) => {
                         logger.info("Uploading signature for " + userId + "...");
                         const response = await this.baseApis.uploadKeySignatures({
                             [userId]: {
@@ -2149,7 +2156,7 @@ export class Crypto extends EventEmitter {
             logger.info("Own device " + deviceId + " marked verified: signing");
 
             // Signing only needed if other device not already signed
-            let device;
+            let device: ISignedKey;
             const deviceTrust = this.checkDeviceTrust(userId, deviceId);
             if (deviceTrust.isCrossSigningVerified()) {
                 logger.log(`Own device ${deviceId} already cross-signing verified`);
@@ -2160,7 +2167,7 @@ export class Crypto extends EventEmitter {
             }
 
             if (device) {
-                const upload = async ({ shouldEmit }) => {
+                const upload = async ({ shouldEmit = false }) => {
                     logger.info("Uploading signature for " + deviceId);
                     const response = await this.baseApis.uploadKeySignatures({
                         [userId]: {
@@ -2204,11 +2211,7 @@ export class Crypto extends EventEmitter {
             return Promise.resolve(existingRequest);
         }
         const channel = new InRoomChannel(this.baseApis, roomId, userId);
-        return this.requestVerificationWithChannel(
-            userId,
-            channel,
-            this.inRoomVerificationRequests,
-        );
+        return this.requestVerificationWithChannel(userId, channel, this.inRoomVerificationRequests);
     }
 
     public requestVerification(userId: string, devices: string[]): Promise<VerificationRequest> {
@@ -2220,17 +2223,13 @@ export class Crypto extends EventEmitter {
             return Promise.resolve(existingRequest);
         }
         const channel = new ToDeviceChannel(this.baseApis, userId, devices, ToDeviceChannel.makeTransactionId());
-        return this.requestVerificationWithChannel(
-            userId,
-            channel,
-            this.toDeviceVerificationRequests,
-        );
+        return this.requestVerificationWithChannel(userId, channel, this.toDeviceVerificationRequests);
     }
 
     private async requestVerificationWithChannel(
         userId: string,
         channel: IVerificationChannel,
-        requestsMap: any, // TODO types
+        requestsMap: IRequestsMap,
     ): Promise<VerificationRequest> {
         let request = new VerificationRequest(channel, this.verificationMethods, this.baseApis);
         // if transaction id is already known, add request
@@ -2618,7 +2617,7 @@ export class Crypto extends EventEmitter {
         users: string[],
         force?: boolean,
     ): Promise<Record<string, Record<string, olmlib.IOlmSessionResult>>> {
-        const devicesByUser = {};
+        const devicesByUser: Record<string, DeviceInfo[]> = {};
 
         for (let i = 0; i < users.length; ++i) {
             const userId = users[i];
@@ -2651,7 +2650,7 @@ export class Crypto extends EventEmitter {
      * @return {module:crypto/OlmDevice.MegolmSessionData[]} a list of session export objects
      */
     public async exportRoomKeys(): Promise<IMegolmSessionData[]> {
-        const exportedSessions = [];
+        const exportedSessions: IMegolmSessionData[] = [];
         await this.cryptoStore.doTxn(
             'readonly', [IndexedDBCryptoStore.STORE_INBOUND_GROUP_SESSIONS], (txn) => {
                 this.cryptoStore.getAllEndToEndInboundGroupSessions(txn, (s) => {
@@ -2729,7 +2728,6 @@ export class Crypto extends EventEmitter {
         }
     }
 
-    /* eslint-disable valid-jsdoc */    //https://github.com/eslint/eslint/issues/7307
     /**
      * Encrypt an event according to the configuration of the room.
      *
@@ -2740,8 +2738,6 @@ export class Crypto extends EventEmitter {
      * @return {Promise?} Promise which resolves when the event has been
      *     encrypted, or null if nothing was needed
      */
-    /* eslint-enable valid-jsdoc */
-    // TODO this return type lies
     public async encryptEvent(event: MatrixEvent, room: Room): Promise<void> {
         if (!room) {
             throw new Error("Cannot send encrypted messages in unknown rooms");
@@ -2783,8 +2779,7 @@ export class Crypto extends EventEmitter {
             delete content['io.element.performance_metrics'];
         }
 
-        const encryptedContent = await alg.encryptMessage(
-            room, event.getType(), content);
+        const encryptedContent = await alg.encryptMessage(room, event.getType(), content);
 
         if (mRelatesTo) {
             encryptedContent['m.relates_to'] = mRelatesTo;
@@ -3154,7 +3149,7 @@ export class Crypto extends EventEmitter {
         if (!ToDeviceChannel.validateEvent(event, this.baseApis)) {
             return;
         }
-        const createRequest = event => {
+        const createRequest = (event: MatrixEvent) => {
             if (!ToDeviceChannel.canCreateRequest(ToDeviceChannel.getEventType(event))) {
                 return;
             }
@@ -3172,11 +3167,7 @@ export class Crypto extends EventEmitter {
             return new VerificationRequest(
                 channel, this.verificationMethods, this.baseApis);
         };
-        this.handleVerificationEvent(
-            event,
-            this.toDeviceVerificationRequests,
-            createRequest,
-        );
+        this.handleVerificationEvent(event, this.toDeviceVerificationRequests, createRequest);
     }
 
     /**
@@ -3199,7 +3190,7 @@ export class Crypto extends EventEmitter {
         if (!InRoomChannel.validateEvent(event, this.baseApis)) {
             return;
         }
-        const createRequest = event => {
+        const createRequest = (event: MatrixEvent) => {
             const channel = new InRoomChannel(
                 this.baseApis,
                 event.getRoomId(),
@@ -3207,18 +3198,13 @@ export class Crypto extends EventEmitter {
             return new VerificationRequest(
                 channel, this.verificationMethods, this.baseApis);
         };
-        this.handleVerificationEvent(
-            event,
-            this.inRoomVerificationRequests,
-            createRequest,
-            liveEvent,
-        );
+        this.handleVerificationEvent(event, this.inRoomVerificationRequests, createRequest, liveEvent);
     };
 
     private async handleVerificationEvent(
         event: MatrixEvent,
-        requestsMap: any, // TODO types
-        createRequest: any, // TODO types
+        requestsMap: IRequestsMap,
+        createRequest: (event: MatrixEvent) => VerificationRequest,
         isLiveEvent = true,
     ): Promise<void> {
         // Wait for event to get its final ID with pendingEventOrdering: "chronological", since DM channels depend on it.
@@ -3332,7 +3318,7 @@ export class Crypto extends EventEmitter {
                 return;
             }
         }
-        const devicesByUser = {};
+        const devicesByUser: Record<string, DeviceInfo[]> = {};
         devicesByUser[sender] = [device];
         await olmlib.ensureOlmSessionsForDevices(this.olmDevice, this.baseApis, devicesByUser, true);
 

src/crypto/olmlib.ts

@@ -28,7 +28,8 @@ import { OlmDevice } from "./OlmDevice";
 import { DeviceInfo } from "./deviceinfo";
 import { logger } from '../logger';
 import { IOneTimeKey } from "./dehydration";
-import { MatrixClient } from "../client";
+import { IClaimOTKsResult, MatrixClient } from "../client";
+import { ISignatures } from "../@types/signed";
 
 enum Algorithm {
     Olm = "m.olm.v1.curve25519-aes-sha2",
@@ -132,6 +133,11 @@ export async function encryptMessageForDevice(
     );
 }
 
+interface IExistingOlmSession {
+    device: DeviceInfo;
+    sessionId?: string;
+}
+
 /**
  * Get the existing olm sessions for the given devices, and the devices that
  * don't have olm sessions.
@@ -152,11 +158,11 @@ export async function getExistingOlmSessions(
     olmDevice: OlmDevice,
     baseApis: MatrixClient,
     devicesByUser: Record<string, DeviceInfo[]>,
-) {
-    const devicesWithoutSession = {};
-    const sessions = {};
+): Promise<[Record<string, DeviceInfo[]>, Record<string, Record<string, IExistingOlmSession>>]> {
+    const devicesWithoutSession: {[userId: string]: DeviceInfo[]} = {};
+    const sessions: {[userId: string]: {[deviceId: string]: IExistingOlmSession}} = {};
 
-    const promises = [];
+    const promises: Promise<void>[] = [];
 
     for (const [userId, devices] of Object.entries(devicesByUser)) {
         for (const deviceInfo of devices) {
@@ -230,10 +236,10 @@ export async function ensureOlmSessionsForDevices(
         force = false;
     }
 
-    const devicesWithoutSession = [
+    const devicesWithoutSession: [string, string][] = [
         // [userId, deviceId], ...
     ];
-    const result = {};
+    const result: {[userId: string]: {[deviceId: string]: IExistingOlmSession}} = {};
     const resolveSession: Record<string, (sessionId?: string) => void> = {};
 
     // Mark all sessions this task intends to update as in progress. It is
@@ -321,9 +327,7 @@ export async function ensureOlmSessionsForDevices(
     let taskDetail = `one-time keys for ${devicesWithoutSession.length} devices`;
     try {
         log.debug(`Claiming ${taskDetail}`);
-        res = await baseApis.claimOneTimeKeys(
-            devicesWithoutSession, oneTimeKeyAlgorithm, otkTimeout,
-        );
+        res = await baseApis.claimOneTimeKeys(devicesWithoutSession, oneTimeKeyAlgorithm, otkTimeout);
         log.debug(`Claimed ${taskDetail}`);
     } catch (e) {
         for (const resolver of Object.values(resolveSession)) {
@@ -337,8 +341,8 @@ export async function ensureOlmSessionsForDevices(
         failedServers.push(...Object.keys(res.failures));
     }
 
-    const otkResult = res.one_time_keys || {};
-    const promises = [];
+    const otkResult = res.one_time_keys || {} as IClaimOTKsResult["one_time_keys"];
+    const promises: Promise<void>[] = [];
     for (const [userId, devices] of Object.entries(devicesByUser)) {
         const userRes = otkResult[userId] || {};
         for (let j = 0; j < devices.length; j++) {
@@ -359,7 +363,7 @@ export async function ensureOlmSessionsForDevices(
             }
 
             const deviceRes = userRes[deviceId] || {};
-            let oneTimeKey = null;
+            let oneTimeKey: IOneTimeKey = null;
             for (const keyId in deviceRes) {
                 if (keyId.indexOf(oneTimeKeyAlgorithm + ":") === 0) {
                     oneTimeKey = deviceRes[keyId];
@@ -441,7 +445,7 @@ async function _verifyKeyAndStartSession(
 
 export interface IObject {
     unsigned?: object;
-    signatures?: object;
+    signatures?: ISignatures;
 }
 
 /**

src/crypto/store/indexeddb-crypto-store-backend.ts

@@ -200,10 +200,10 @@ export class Backend implements CryptoStore {
 
         // index into the wantedStates array
         let stateIndex = 0;
-        let result;
+        let result: OutgoingRoomKeyRequest;
 
-        function onsuccess(ev) {
-            const cursor = ev.target.result;
+        function onsuccess(this: IDBRequest<IDBCursorWithValue>) {
+            const cursor = this.result;
             if (cursor) {
                 // got a match
                 result = cursor.value;
@@ -218,7 +218,7 @@ export class Backend implements CryptoStore {
             }
 
             const wantedState = wantedStates[stateIndex];
-            const cursorReq = ev.target.source.openCursor(wantedState);
+            const cursorReq = (this.source as IDBIndex).openCursor(wantedState);
             cursorReq.onsuccess = onsuccess;
         }
 
@@ -255,10 +255,10 @@ export class Backend implements CryptoStore {
         wantedStates: number[],
     ): Promise<OutgoingRoomKeyRequest[]> {
         let stateIndex = 0;
-        const results = [];
+        const results: OutgoingRoomKeyRequest[] = [];
 
-        function onsuccess(ev) {
-            const cursor = ev.target.result;
+        function onsuccess(this: IDBRequest<IDBCursorWithValue>) {
+            const cursor = this.result;
             if (cursor) {
                 const keyReq = cursor.value;
                 if (keyReq.recipients.includes({ userId, deviceId })) {
@@ -274,7 +274,7 @@ export class Backend implements CryptoStore {
                 }
 
                 const wantedState = wantedStates[stateIndex];
-                const cursorReq = ev.target.source.openCursor(wantedState);
+                const cursorReq = (this.source as IDBIndex).openCursor(wantedState);
                 cursorReq.onsuccess = onsuccess;
             }
         }
@@ -306,10 +306,10 @@ export class Backend implements CryptoStore {
         expectedState: number,
         updates: Partial<OutgoingRoomKeyRequest>,
     ): Promise<OutgoingRoomKeyRequest | null> {
-        let result = null;
+        let result: OutgoingRoomKeyRequest = null;
 
-        function onsuccess(ev) {
-            const cursor = ev.target.result;
+        function onsuccess(this: IDBRequest<IDBCursorWithValue>) {
+            const cursor = this.result;
             if (!cursor) {
                 return;
             }
@@ -444,7 +444,7 @@ export class Backend implements CryptoStore {
         const objectStore = txn.objectStore("sessions");
         const idx = objectStore.index("deviceKey");
         const getReq = idx.openCursor(deviceKey);
-        const results = {};
+        const results: Parameters<Parameters<Backend["getEndToEndSessions"]>[2]>[0] = {};
         getReq.onsuccess = function() {
             const cursor = getReq.result;
             if (cursor) {
@@ -734,7 +734,7 @@ export class Backend implements CryptoStore {
     }
 
     public getEndToEndRooms(txn: IDBTransaction, func: (rooms: Record<string, IRoomEncryption>) => void): void {
-        const rooms = {};
+        const rooms: Parameters<Parameters<Backend["getEndToEndRooms"]>[1]>[0] = {};
         const objectStore = txn.objectStore("rooms");
         const getReq = objectStore.openCursor();
         getReq.onsuccess = function() {
@@ -756,7 +756,7 @@ export class Backend implements CryptoStore {
 
     public getSessionsNeedingBackup(limit: number): Promise<ISession[]> {
         return new Promise((resolve, reject) => {
-            const sessions = [];
+            const sessions: ISession[] = [];
 
             const txn = this.db.transaction(
                 ["sessions_needing_backup", "inbound_group_sessions"],
@@ -877,8 +877,8 @@ export class Backend implements CryptoStore {
         func: (txn: IDBTransaction) => T,
         log: PrefixedLogger = logger,
     ): Promise<T> {
-        let startTime;
-        let description;
+        let startTime: number;
+        let description: string;
         if (PROFILE_TRANSACTIONS) {
             const txnId = this.nextTxnId++;
             startTime = Date.now();

src/crypto/store/localStorage-crypto-store.ts

@@ -175,8 +175,10 @@ export class LocalStorageCryptoStore extends MemoryCryptoStore {
     }
 
     public async filterOutNotifiedErrorDevices(devices: IOlmDevice[]): Promise<IOlmDevice[]> {
-        const notifiedErrorDevices = getJsonItem<string[]>(this.store, KEY_NOTIFIED_ERROR_DEVICES) || {};
-        const ret = [];
+        const notifiedErrorDevices = getJsonItem<MemoryCryptoStore["notifiedErrorDevices"]>(
+            this.store, KEY_NOTIFIED_ERROR_DEVICES,
+        ) || {};
+        const ret: IOlmDevice[] = [];
 
         for (const device of devices) {
             const { userId, deviceInfo } = device;
@@ -291,7 +293,7 @@ export class LocalStorageCryptoStore extends MemoryCryptoStore {
     }
 
     public getEndToEndRooms(txn: unknown, func: (rooms: Record<string, IRoomEncryption>) => void): void {
-        const result = {};
+        const result: Record<string, IRoomEncryption> = {};
         const prefix = keyEndToEndRoomsPrefix('');
 
         for (let i = 0; i < this.store.length; ++i) {
@@ -306,7 +308,7 @@ export class LocalStorageCryptoStore extends MemoryCryptoStore {
 
     public getSessionsNeedingBackup(limit: number): Promise<ISession[]> {
         const sessionsNeedingBackup = getJsonItem<string[]>(this.store, KEY_SESSIONS_NEEDING_BACKUP) || {};
-        const sessions = [];
+        const sessions: ISession[] = [];
 
         for (const session in sessionsNeedingBackup) {
             if (Object.prototype.hasOwnProperty.call(sessionsNeedingBackup, session)) {

src/crypto/verification/request/Channel.ts

@@ -30,4 +30,5 @@ export interface IVerificationChannel {
     sendCompleted(type: string, content: Record<string, any>): Promise<void>;
     completedContentFromEvent(event: MatrixEvent): Record<string, any>;
     canCreateRequest(type: string): boolean;
+    handleEvent(event: MatrixEvent, request: VerificationRequest, isLiveEvent: boolean): Promise<void>;
 }

src/crypto/verification/request/InRoomChannel.ts

@@ -26,6 +26,7 @@ import { IVerificationChannel } from "./Channel";
 import { EventType } from "../../../@types/event";
 import { MatrixClient } from "../../../client";
 import { MatrixEvent } from "../../../models/event";
+import { IRequestsMap } from "../..";
 
 const MESSAGE_TYPE = EventType.RoomMessage;
 const M_REFERENCE = "m.reference";
@@ -304,7 +305,7 @@ export class InRoomChannel implements IVerificationChannel {
     }
 }
 
-export class InRoomRequests {
+export class InRoomRequests implements IRequestsMap {
     private requestsByRoomId = new Map<string, Map<string, VerificationRequest>>();
 
     public getRequest(event: MatrixEvent): VerificationRequest {
@@ -328,7 +329,7 @@ export class InRoomRequests {
         this.doSetRequest(event.getRoomId(), InRoomChannel.getTransactionId(event), request);
     }
 
-    public setRequestByChannel(channel: InRoomChannel, request: VerificationRequest): void {
+    public setRequestByChannel(channel: IVerificationChannel, request: VerificationRequest): void {
         this.doSetRequest(channel.roomId, channel.transactionId, request);
     }
 

src/crypto/verification/request/ToDeviceChannel.ts

@@ -30,8 +30,9 @@ import { errorFromEvent, newUnexpectedMessageError } from "../Error";
 import { MatrixEvent } from "../../../models/event";
 import { IVerificationChannel } from "./Channel";
 import { MatrixClient } from "../../../client";
+import { IRequestsMap } from '../..';
 
-type Request = VerificationRequest<ToDeviceChannel>;
+export type Request = VerificationRequest<ToDeviceChannel>;
 
 /**
  * A key verification channel that sends verification events over to_device messages.
@@ -276,7 +277,7 @@ export class ToDeviceChannel implements IVerificationChannel {
 
     private async sendToDevices(type: string, content: Record<string, any>, devices: string[]): Promise<void> {
         if (devices.length) {
-            const msgMap = {};
+            const msgMap: Record<string, Record<string, any>> = {};
             for (const deviceId of devices) {
                 msgMap[deviceId] = content;
             }
@@ -294,7 +295,7 @@ export class ToDeviceChannel implements IVerificationChannel {
     }
 }
 
-export class ToDeviceRequests {
+export class ToDeviceRequests implements IRequestsMap {
     private requestsByUserId = new Map<string, Map<string, Request>>();
 
     public getRequest(event: MatrixEvent): Request {

src/crypto/verification/request/VerificationRequest.ts

@@ -582,7 +582,9 @@ export class VerificationRequest<C extends IVerificationChannel = IVerificationC
         // get common methods
         if (phase === PHASE_REQUESTED || phase === PHASE_READY) {
             if (!this.wasSentByOwnDevice(event)) {
-                const content = event.getContent();
+                const content = event.getContent<{
+                    methods: string[];
+                }>();
                 this.commonMethods =
                     content.methods.filter(m => this.verificationMethods.has(m));
             }

src/event-mapper.ts

@@ -41,7 +41,7 @@ export function eventMapperFor(client: MatrixClient, options: MapperOpts): Event
             }
         }
         if (!preventReEmit) {
-            client.reEmitter.reEmit(event, ["Event.replaced"]);
+            client.reEmitter.reEmit(event, ["Event.replaced", "Event.visibilityChange"]);
         }
         return event;
     }

src/filter-component.ts

@@ -14,6 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import { RelationType } from "./@types/event";
+import { UNSTABLE_FILTER_RELATION_SENDERS, UNSTABLE_FILTER_RELATION_TYPES } from "./filter";
 import { MatrixEvent } from "./models/event";
 
 /**
@@ -46,6 +48,7 @@ export interface IFilterComponent {
     not_senders?: string[];
     contains_url?: boolean;
     limit?: number;
+    [UNSTABLE_FILTER_RELATION_TYPES.name]?: Array<RelationType | string>;
 }
 /* eslint-enable camelcase */
 
@@ -61,7 +64,7 @@ export interface IFilterComponent {
  * @param {Object} filterJson the definition of this filter JSON, e.g. { 'contains_url': true }
  */
 export class FilterComponent {
-    constructor(private filterJson: IFilterComponent) {}
+    constructor(private filterJson: IFilterComponent, public readonly userId?: string) {}
 
     /**
      * Checks with the filter component matches the given event
@@ -69,11 +72,24 @@ export class FilterComponent {
      * @return {boolean} true if the event matches the filter
      */
     public check(event: MatrixEvent): boolean {
+        const bundledRelationships = event.getUnsigned()?.["m.relations"] || {};
+        const relations: Array<string | RelationType> = Object.keys(bundledRelationships);
+        // Relation senders allows in theory a look-up of any senders
+        // however clients can only know about the current user participation status
+        // as sending a whole list of participants could be proven problematic in terms
+        // of performance
+        // This should be improved when bundled relationships solve that problem
+        const relationSenders = [];
+        if (this.userId && relations?.[RelationType.Thread]?.current_user_participated) {
+            relationSenders.push(this.userId);
+        }
         return this.checkFields(
             event.getRoomId(),
             event.getSender(),
             event.getType(),
             event.getContent() ? event.getContent().url !== undefined : false,
+            relations,
+            relationSenders,
         );
     }
 
@@ -89,6 +105,8 @@ export class FilterComponent {
             senders: this.filterJson.senders || null,
             not_senders: this.filterJson.not_senders || [],
             contains_url: this.filterJson.contains_url || null,
+            [UNSTABLE_FILTER_RELATION_SENDERS.name]: UNSTABLE_FILTER_RELATION_SENDERS.findIn(this.filterJson),
+            [UNSTABLE_FILTER_RELATION_TYPES.name]: UNSTABLE_FILTER_RELATION_TYPES.findIn(this.filterJson),
         };
     }
 
@@ -98,9 +116,18 @@ export class FilterComponent {
      * @param {String} sender        the sender of the event being checked
      * @param {String} eventType     the type of the event being checked
      * @param {boolean} containsUrl  whether the event contains a content.url field
+     * @param {boolean} relationTypes  whether has aggregated relation of the given type
+     * @param {boolean} relationSenders whether one of the relation is sent by the user listed
      * @return {boolean} true if the event fields match the filter
      */
-    private checkFields(roomId: string, sender: string, eventType: string, containsUrl: boolean): boolean {
+    private checkFields(
+        roomId: string,
+        sender: string,
+        eventType: string,
+        containsUrl: boolean,
+        relationTypes: Array<RelationType | string>,
+        relationSenders: string[],
+    ): boolean {
         const literalKeys = {
             "rooms": function(v: string): boolean {
                 return roomId === v;
@@ -133,15 +160,35 @@ export class FilterComponent {
             return false;
         }
 
+        const relationTypesFilter = this.filterJson[UNSTABLE_FILTER_RELATION_TYPES.name];
+        if (relationTypesFilter !== undefined) {
+            if (!this.arrayMatchesFilter(relationTypesFilter, relationTypes)) {
+                return false;
+            }
+        }
+
+        const relationSendersFilter = this.filterJson[UNSTABLE_FILTER_RELATION_SENDERS.name];
+        if (relationSendersFilter !== undefined) {
+            if (!this.arrayMatchesFilter(relationSendersFilter, relationSenders)) {
+                return false;
+            }
+        }
+
         return true;
     }
 
+    private arrayMatchesFilter(filter: any[], values: any[]): boolean {
+        return values.length > 0 && values.every(value => {
+            return filter.includes(value);
+        });
+    }
+
     /**
      * Filters a list of events down to those which match this filter component
      * @param {MatrixEvent[]} events  Events to be checked against the filter component
      * @return {MatrixEvent[]} events which matched the filter component
      */
-    filter(events: MatrixEvent[]): MatrixEvent[] {
+    public filter(events: MatrixEvent[]): MatrixEvent[] {
         return events.filter(this.check, this);
     }
 
@@ -150,7 +197,7 @@ export class FilterComponent {
      * 10 if none is otherwise specified. Cargo-culted from Synapse.
      * @return {Number} the limit for this filter component.
      */
-    limit(): number {
+    public limit(): number {
         return this.filterJson.limit !== undefined ? this.filterJson.limit : 10;
     }
 }

src/filter.ts

@@ -65,7 +65,7 @@ export interface IFilterDefinition {
 export interface IRoomEventFilter extends IFilterComponent {
     lazy_load_members?: boolean;
     include_redundant_members?: boolean;
-    types?: EventType[] | string[];
+    types?: Array<EventType | string>;
     [UNSTABLE_FILTER_RELATION_TYPES.name]?: Array<RelationType | string>;
     [UNSTABLE_FILTER_RELATION_SENDERS.name]?: string[];
 }
@@ -185,8 +185,8 @@ export class Filter {
             }
         }
 
-        this.roomFilter = new FilterComponent(roomFilterFields);
-        this.roomTimelineFilter = new FilterComponent(roomFilterJson?.timeline || {});
+        this.roomFilter = new FilterComponent(roomFilterFields, this.userId);
+        this.roomTimelineFilter = new FilterComponent(roomFilterJson?.timeline || {}, this.userId);
 
         // don't bother porting this from synapse yet:
         // this._room_state_filter =

src/http-api.ts

@@ -1,6 +1,6 @@
 /*
 Copyright 2015, 2016 OpenMarket Ltd
-Copyright 2019 The Matrix.org Foundation C.I.C.
+Copyright 2019 - 2021 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.
@@ -20,14 +20,21 @@ limitations under the License.
  * @module http-api
  */
 
-import { parse as parseContentType } from "content-type";
+import { parse as parseContentType, ParsedMediaType } from "content-type";
+import EventEmitter from "events";
 
-import * as utils from "./utils";
-import { logger } from './logger';
+import type { IncomingHttpHeaders, IncomingMessage } from "http";
+import type { Request as _Request, CoreOptions } from "request";
 // we use our own implementation of setTimeout, so that if we get suspended in
 // the middle of a /sync, we cancel the sync as soon as we awake, rather than
 // waiting for the delay to elapse.
 import * as callbacks from "./realtime-callbacks";
+import { IUploadOpts } from "./@types/requests";
+import { IAbortablePromise, IUsageLimit } from "./@types/partials";
+import { IDeferred } from "./utils";
+import { Callback } from "./client";
+import * as utils from "./utils";
+import { logger } from './logger';
 
 /*
 TODO:
@@ -40,6 +47,11 @@ TODO:
  */
 export const PREFIX_R0 = "/_matrix/client/r0";
 
+/**
+ * A constant representing the URI path for release v1 of the Client-Server HTTP API.
+ */
+export const PREFIX_V1 = "/_matrix/client/v1";
+
 /**
  * A constant representing the URI path for as-yet unspecified Client-Server HTTP APIs.
  */
@@ -61,10 +73,95 @@ export const PREFIX_IDENTITY_V2 = "/_matrix/identity/v2";
  */
 export const PREFIX_MEDIA_R0 = "/_matrix/media/r0";
 
+type RequestProps = "method"
+    | "withCredentials"
+    | "json"
+    | "headers"
+    | "qs"
+    | "body"
+    | "qsStringifyOptions"
+    | "useQuerystring"
+    | "timeout";
+
+export interface IHttpOpts {
+    baseUrl: string;
+    idBaseUrl?: string;
+    prefix: string;
+    onlyData: boolean;
+    accessToken?: string;
+    extraParams?: Record<string, string>;
+    localTimeoutMs?: number;
+    useAuthorizationHeader?: boolean;
+    request(opts: Pick<CoreOptions, RequestProps> & {
+        uri: string;
+        method: Method;
+        // eslint-disable-next-line camelcase
+        _matrix_opts: IHttpOpts;
+    }, callback: RequestCallback): IRequest;
+}
+
+interface IRequest extends _Request {
+    onprogress?(e: unknown): void;
+}
+
+interface IRequestOpts<T> {
+    prefix?: string;
+    localTimeoutMs?: number;
+    headers?: Record<string, string>;
+    json?: boolean; // defaults to true
+    qsStringifyOptions?: CoreOptions["qsStringifyOptions"];
+    bodyParser?(body: string): T;
+}
+
+export interface IUpload {
+    loaded: number;
+    total: number;
+    promise: IAbortablePromise<unknown>;
+}
+
+interface IContentUri {
+    base: string;
+    path: string;
+    params: {
+        // eslint-disable-next-line camelcase
+        access_token: string;
+    };
+}
+
+type ResponseType<T, O extends IRequestOpts<T> | void = void> =
+    O extends { bodyParser: (body: string) => T } ? T :
+    O extends { json: false } ? string :
+    T;
+
+interface IUploadResponse {
+    // eslint-disable-next-line camelcase
+    content_uri: string;
+}
+
+// This type's defaults only work for the Browser
+// in the Browser we default rawResponse = false & onlyContentUri = true
+// in Node we default rawResponse = true & onlyContentUri = false
+export type UploadContentResponseType<O extends IUploadOpts> =
+    O extends undefined ? string :
+    O extends { rawResponse: true } ? string :
+    O extends { onlyContentUri: true } ? string :
+    O extends { rawResponse: false } ? IUploadResponse :
+    O extends { onlyContentUri: false } ? IUploadResponse :
+    string;
+
+export enum Method {
+    Get = "GET",
+    Put = "PUT",
+    Post = "POST",
+    Delete = "DELETE",
+}
+
+export type FileType = Document | XMLHttpRequestBodyInit;
+
 /**
  * Construct a MatrixHttpApi.
  * @constructor
- * @param {EventEmitter} event_emitter The event emitter to use for emitting events
+ * @param {EventEmitter} eventEmitter The event emitter to use for emitting events
  * @param {Object} opts The options to use for this HTTP API.
  * @param {string} opts.baseUrl Required. The base client-server URL e.g.
  * 'http://localhost:8008'.
@@ -77,7 +174,7 @@ export const PREFIX_MEDIA_R0 = "/_matrix/media/r0";
  * response (e.g. the parsed HTTP body). If false, requests will return an
  * object with the properties <tt>code</tt>, <tt>headers</tt> and <tt>data</tt>.
  *
- * @param {string} opts.accessToken The access_token to send with requests. Can be
+ * @param {string=} opts.accessToken The access_token to send with requests. Can be
  * null to not send an access token.
  * @param {Object=} opts.extraParams Optional. Extra query parameters to send on
  * requests.
@@ -86,39 +183,37 @@ export const PREFIX_MEDIA_R0 = "/_matrix/media/r0";
  * @param {boolean} [opts.useAuthorizationHeader = false] Set to true to use
  * Authorization header instead of query param to send the access token to the server.
  */
-export function MatrixHttpApi(event_emitter, opts) {
-    utils.checkObjectHasKeys(opts, ["baseUrl", "request", "prefix"]);
-    opts.onlyData = opts.onlyData || false;
-    this.event_emitter = event_emitter;
-    this.opts = opts;
-    this.useAuthorizationHeader = Boolean(opts.useAuthorizationHeader);
-    this.uploads = [];
-}
+export class MatrixHttpApi {
+    private uploads: IUpload[] = [];
+
+    constructor(private eventEmitter: EventEmitter, public readonly opts: IHttpOpts) {
+        utils.checkObjectHasKeys(opts, ["baseUrl", "request", "prefix"]);
+        opts.onlyData = !!opts.onlyData;
+        opts.useAuthorizationHeader = !!opts.useAuthorizationHeader;
+    }
 
-MatrixHttpApi.prototype = {
     /**
-     * Sets the baase URL for the identity server
+     * Sets the base URL for the identity server
      * @param {string} url The new base url
      */
-    setIdBaseUrl: function(url) {
+    public setIdBaseUrl(url: string): void {
         this.opts.idBaseUrl = url;
-    },
+    }
 
     /**
      * Get the content repository url with query parameters.
      * @return {Object} An object with a 'base', 'path' and 'params' for base URL,
      *          path and query parameters respectively.
      */
-    getContentUri: function() {
-        const params = {
-            access_token: this.opts.accessToken,
-        };
+    public getContentUri(): IContentUri {
         return {
             base: this.opts.baseUrl,
             path: "/_matrix/media/r0/upload",
-            params: params,
+            params: {
+                access_token: this.opts.accessToken,
+            },
         };
-    },
+    }
 
     /**
      * Upload content to the homeserver
@@ -160,14 +255,17 @@ MatrixHttpApi.prototype = {
      *    determined by this.opts.onlyData, opts.rawResponse, and
      *    opts.onlyContentUri.  Rejects with an error (usually a MatrixError).
      */
-    uploadContent: function(file, opts) {
+    public uploadContent<O extends IUploadOpts>(
+        file: FileType,
+        opts?: O,
+    ): IAbortablePromise<UploadContentResponseType<O>> {
         if (utils.isFunction(opts)) {
-            // opts used to be callback
+            // opts used to be callback, backwards compatibility
             opts = {
-                callback: opts,
-            };
-        } else if (opts === undefined) {
-            opts = {};
+                callback: opts as unknown as IUploadOpts["callback"],
+            } as O;
+        } else if (!opts) {
+            opts = {} as O;
         }
 
         // default opts.includeFilename to true (ignoring falsey values)
@@ -175,8 +273,8 @@ MatrixHttpApi.prototype = {
 
         // if the file doesn't have a mime type, use a default since
         // the HS errors if we don't supply one.
-        const contentType = opts.type || file.type || 'application/octet-stream';
-        const fileName = opts.name || file.name;
+        const contentType = opts.type || (file as File).type || 'application/octet-stream';
+        const fileName = opts.name || (file as File).name;
 
         // We used to recommend setting file.stream to the thing to upload on
         // Node.js. As of 2019-06-11, this is still in widespread use in various
@@ -185,13 +283,14 @@ MatrixHttpApi.prototype = {
         // the browser now define a `stream` method, which leads to trouble
         // here, so we also check the type of `stream`.
         let body = file;
-        if (body.stream && typeof body.stream !== "function") {
+        const bodyStream = (body as File | Blob).stream; // this type is wrong but for legacy reasons is good enough
+        if (bodyStream && typeof bodyStream !== "function") {
             logger.warn(
                 "Using `file.stream` as the content to upload. Future " +
                 "versions of the js-sdk will change this to expect `file` to " +
                 "be the content directly.",
             );
-            body = body.stream;
+            body = bodyStream;
         }
 
         // backwards-compatibility hacks where we used to do different things
@@ -234,8 +333,8 @@ MatrixHttpApi.prototype = {
         // (browser-request doesn't support progress either, which is also kind
         // of important here)
 
-        const upload = { loaded: 0, total: 0 };
-        let promise;
+        const upload = { loaded: 0, total: 0 } as IUpload;
+        let promise: IAbortablePromise<UploadContentResponseType<O>>;
 
         // XMLHttpRequest doesn't parse JSON for us. request normally does, but
         // we're setting opts.json=false so that it doesn't JSON-encode the
@@ -243,7 +342,7 @@ MatrixHttpApi.prototype = {
         // way, we have to JSON-parse the response ourselves.
         let bodyParser = null;
         if (!rawResponse) {
-            bodyParser = function(rawBody) {
+            bodyParser = function(rawBody: string) {
                 let body = JSON.parse(rawBody);
                 if (onlyContentUri) {
                     body = body.content_uri;
@@ -256,25 +355,23 @@ MatrixHttpApi.prototype = {
         }
 
         if (global.XMLHttpRequest) {
-            const defer = utils.defer();
+            const defer = utils.defer<UploadContentResponseType<O>>();
             const xhr = new global.XMLHttpRequest();
-            upload.xhr = xhr;
             const cb = requestCallback(defer, opts.callback, this.opts.onlyData);
 
-            const timeout_fn = function() {
+            const timeoutFn = function() {
                 xhr.abort();
                 cb(new Error('Timeout'));
             };
 
-            // set an initial timeout of 30s; we'll advance it each time we get
-            // a progress notification
-            xhr.timeout_timer = callbacks.setTimeout(timeout_fn, 30000);
+            // set an initial timeout of 30s; we'll advance it each time we get a progress notification
+            let timeoutTimer = callbacks.setTimeout(timeoutFn, 30000);
 
             xhr.onreadystatechange = function() {
-                let resp;
+                let resp: string;
                 switch (xhr.readyState) {
                     case global.XMLHttpRequest.DONE:
-                        callbacks.clearTimeout(xhr.timeout_timer);
+                        callbacks.clearTimeout(timeoutTimer);
                         try {
                             if (xhr.status === 0) {
                                 throw new AbortError();
@@ -296,10 +393,10 @@ MatrixHttpApi.prototype = {
                 }
             };
             xhr.upload.addEventListener("progress", function(ev) {
-                callbacks.clearTimeout(xhr.timeout_timer);
+                callbacks.clearTimeout(timeoutTimer);
                 upload.loaded = ev.loaded;
                 upload.total = ev.total;
-                xhr.timeout_timer = callbacks.setTimeout(timeout_fn, 30000);
+                timeoutTimer = callbacks.setTimeout(timeoutFn, 30000);
                 if (opts.progressHandler) {
                     opts.progressHandler({
                         loaded: ev.loaded,
@@ -315,9 +412,8 @@ MatrixHttpApi.prototype = {
                 queryArgs.push("filename=" + encodeURIComponent(fileName));
             }
 
-            if (!this.useAuthorizationHeader) {
-                queryArgs.push("access_token="
-                    + encodeURIComponent(this.opts.accessToken));
+            if (!this.opts.useAuthorizationHeader) {
+                queryArgs.push("access_token=" + encodeURIComponent(this.opts.accessToken));
             }
 
             if (queryArgs.length > 0) {
@@ -325,73 +421,69 @@ MatrixHttpApi.prototype = {
             }
 
             xhr.open("POST", url);
-            if (this.useAuthorizationHeader) {
+            if (this.opts.useAuthorizationHeader) {
                 xhr.setRequestHeader("Authorization", "Bearer " + this.opts.accessToken);
             }
             xhr.setRequestHeader("Content-Type", contentType);
             xhr.send(body);
-            promise = defer.promise;
+            promise = defer.promise as IAbortablePromise<UploadContentResponseType<O>>;
 
-            // dirty hack (as per _request) to allow the upload to be cancelled.
+            // dirty hack (as per doRequest) to allow the upload to be cancelled.
             promise.abort = xhr.abort.bind(xhr);
         } else {
-            const queryParams = {};
+            const queryParams: Record<string, string> = {};
 
             if (includeFilename && fileName) {
                 queryParams.filename = fileName;
             }
 
             promise = this.authedRequest(
-                opts.callback, "POST", "/upload", queryParams, body, {
+                opts.callback, Method.Post, "/upload", queryParams, body, {
                     prefix: "/_matrix/media/r0",
                     headers: { "Content-Type": contentType },
                     json: false,
-                    bodyParser: bodyParser,
+                    bodyParser,
                 },
             );
         }
 
-        const self = this;
-
         // remove the upload from the list on completion
-        const promise0 = promise.finally(function() {
-            for (let i = 0; i < self.uploads.length; ++i) {
-                if (self.uploads[i] === upload) {
-                    self.uploads.splice(i, 1);
+        upload.promise = promise.finally(() => {
+            for (let i = 0; i < this.uploads.length; ++i) {
+                if (this.uploads[i] === upload) {
+                    this.uploads.splice(i, 1);
                     return;
                 }
             }
-        });
+        }) as IAbortablePromise<UploadContentResponseType<O>>;
 
         // copy our dirty abort() method to the new promise
-        promise0.abort = promise.abort;
-
-        upload.promise = promise0;
+        upload.promise.abort = promise.abort;
         this.uploads.push(upload);
 
-        return promise0;
-    },
+        return upload.promise as IAbortablePromise<UploadContentResponseType<O>>;
+    }
 
-    cancelUpload: function(promise) {
+    public cancelUpload(promise: IAbortablePromise<unknown>): boolean {
         if (promise.abort) {
             promise.abort();
             return true;
         }
         return false;
-    },
+    }
 
-    getCurrentUploads: function() {
+    public getCurrentUploads(): IUpload[] {
         return this.uploads;
-    },
+    }
 
-    idServerRequest: function(
-        callback,
-        method,
-        path,
-        params,
-        prefix,
-        accessToken,
-    ) {
+    public idServerRequest<T>(
+        callback: Callback<T>,
+        method: Method,
+        path: string,
+        params: Record<string, string | string[]>,
+        prefix: string,
+        accessToken: string,
+    ): Promise<T> {
         if (!this.opts.idBaseUrl) {
             throw new Error("No identity server base URL set");
         }
@@ -406,28 +498,27 @@ MatrixHttpApi.prototype = {
 
         const opts = {
             uri: fullUri,
-            method: method,
+            method,
             withCredentials: false,
             json: true, // we want a JSON response if we can
             _matrix_opts: this.opts,
             headers: {},
-        };
-        if (method === 'GET') {
+        } as Parameters<IHttpOpts["request"]>[0];
+
+        if (method === Method.Get) {
             opts.qs = params;
         } else if (typeof params === "object") {
             opts.json = params;
         }
+
         if (accessToken) {
             opts.headers['Authorization'] = `Bearer ${accessToken}`;
         }
 
-        const defer = utils.defer();
-        this.opts.request(
-            opts,
-            requestCallback(defer, callback, this.opts.onlyData),
-        );
+        const defer = utils.defer<T>();
+        this.opts.request(opts, requestCallback(defer, callback, this.opts.onlyData));
         return defer.promise;
-    },
+    }
 
     /**
      * Perform an authorised request to the homeserver.
@@ -448,7 +539,7 @@ MatrixHttpApi.prototype = {
      * @param {Number=} opts.localTimeoutMs The maximum amount of time to wait before
      * timing out the request. If not specified, there is no timeout.
      *
-     * @param {sting=} opts.prefix The full prefix to use e.g.
+     * @param {string=} opts.prefix The full prefix to use e.g.
      * "/_matrix/client/v2_alpha". If not specified, uses this.opts.prefix.
      *
      * @param {Object=} opts.headers map of additional request headers
@@ -460,45 +551,45 @@ MatrixHttpApi.prototype = {
      * @return {module:http-api.MatrixError} Rejects with an error if a problem
      * occurred. This includes network problems and Matrix-specific error JSON.
      */
-    authedRequest: function(callback, method, path, queryParams, data, opts) {
-        if (!queryParams) {
-            queryParams = {};
-        }
-        if (this.useAuthorizationHeader) {
-            if (isFinite(opts)) {
+    public authedRequest<T, O extends IRequestOpts<T> = IRequestOpts<T>>(
+        callback: Callback<T>,
+        method: Method,
+        path: string,
+        queryParams?: Record<string, string | string[]>,
+        data?: CoreOptions["body"],
+        opts?: O | number, // number is legacy
+    ): IAbortablePromise<ResponseType<T, O>> {
+        if (!queryParams) queryParams = {};
+        let requestOpts = (opts || {}) as O;
+
+        if (this.opts.useAuthorizationHeader) {
+            if (isFinite(opts as number)) {
                 // opts used to be localTimeoutMs
-                opts = {
-                    localTimeoutMs: opts,
-                };
+                requestOpts = {
+                    localTimeoutMs: opts as number,
+                } as O;
             }
-            if (!opts) {
-                opts = {};
+
+            if (!requestOpts.headers) {
+                requestOpts.headers = {};
             }
-            if (!opts.headers) {
-                opts.headers = {};
-            }
-            if (!opts.headers.Authorization) {
-                opts.headers.Authorization = "Bearer " + this.opts.accessToken;
+            if (!requestOpts.headers.Authorization) {
+                requestOpts.headers.Authorization = "Bearer " + this.opts.accessToken;
             }
             if (queryParams.access_token) {
                 delete queryParams.access_token;
             }
-        } else {
-            if (!queryParams.access_token) {
-                queryParams.access_token = this.opts.accessToken;
-            }
+        } else if (!queryParams.access_token) {
+            queryParams.access_token = this.opts.accessToken;
         }
 
-        const requestPromise = this.request(
-            callback, method, path, queryParams, data, opts,
-        );
+        const requestPromise = this.request<T, O>(callback, method, path, queryParams, data, requestOpts);
 
-        const self = this;
-        requestPromise.catch(function(err) {
+        requestPromise.catch((err: MatrixError) => {
             if (err.errcode == 'M_UNKNOWN_TOKEN') {
-                self.event_emitter.emit("Session.logged_out", err);
+                this.eventEmitter.emit("Session.logged_out", err);
             } else if (err.errcode == 'M_CONSENT_NOT_GIVEN') {
-                self.event_emitter.emit(
+                this.eventEmitter.emit(
                     "no_consent",
                     err.message,
                     err.data.consent_uri,
@@ -509,7 +600,7 @@ MatrixHttpApi.prototype = {
         // return the original promise, otherwise tests break due to it having to
         // go around the event loop one more time to process the result of the request
         return requestPromise;
-    },
+    }
 
     /**
      * Perform a request to the homeserver without any credentials.
@@ -529,7 +620,7 @@ MatrixHttpApi.prototype = {
      * @param {Number=} opts.localTimeoutMs The maximum amount of time to wait before
      * timing out the request. If not specified, there is no timeout.
      *
-     * @param {sting=} opts.prefix The full prefix to use e.g.
+     * @param {string=} opts.prefix The full prefix to use e.g.
      * "/_matrix/client/v2_alpha". If not specified, uses this.opts.prefix.
      *
      * @param {Object=} opts.headers map of additional request headers
@@ -541,15 +632,19 @@ MatrixHttpApi.prototype = {
      * @return {module:http-api.MatrixError} Rejects with an error if a problem
      * occurred. This includes network problems and Matrix-specific error JSON.
      */
-    request: function(callback, method, path, queryParams, data, opts) {
-        opts = opts || {};
-        const prefix = opts.prefix !== undefined ? opts.prefix : this.opts.prefix;
+    public request<T, O extends IRequestOpts<T> = IRequestOpts<T>>(
+        callback: Callback<T>,
+        method: Method,
+        path: string,
+        queryParams?: CoreOptions["qs"],
+        data?: CoreOptions["body"],
+        opts?: O,
+    ): IAbortablePromise<ResponseType<T, O>> {
+        const prefix = opts?.prefix ?? this.opts.prefix;
         const fullUri = this.opts.baseUrl + prefix + path;
 
-        return this.requestOtherUrl(
-            callback, method, fullUri, queryParams, data, opts,
-        );
-    },
+        return this.requestOtherUrl<T, O>(callback, method, fullUri, queryParams, data, opts);
+    }
 
     /**
      * Perform a request to an arbitrary URL.
@@ -568,7 +663,7 @@ MatrixHttpApi.prototype = {
      * @param {Number=} opts.localTimeoutMs The maximum amount of time to wait before
      * timing out the request. If not specified, there is no timeout.
      *
-     * @param {sting=} opts.prefix The full prefix to use e.g.
+     * @param {string=} opts.prefix The full prefix to use e.g.
      * "/_matrix/client/v2_alpha". If not specified, uses this.opts.prefix.
      *
      * @param {Object=} opts.headers map of additional request headers
@@ -580,21 +675,24 @@ MatrixHttpApi.prototype = {
      * @return {module:http-api.MatrixError} Rejects with an error if a problem
      * occurred. This includes network problems and Matrix-specific error JSON.
      */
-    requestOtherUrl: function(callback, method, uri, queryParams, data,
-                              opts) {
-        if (opts === undefined || opts === null) {
-            opts = {};
-        } else if (isFinite(opts)) {
+    public requestOtherUrl<T, O extends IRequestOpts<T> = IRequestOpts<T>>(
+        callback: Callback<T>,
+        method: Method,
+        uri: string,
+        queryParams?: CoreOptions["qs"],
+        data?: CoreOptions["body"],
+        opts?: O | number, // number is legacy
+    ): IAbortablePromise<ResponseType<T, O>> {
+        let requestOpts = (opts || {}) as O;
+        if (isFinite(opts as number)) {
             // opts used to be localTimeoutMs
-            opts = {
-                localTimeoutMs: opts,
-            };
+            requestOpts = {
+                localTimeoutMs: opts as number,
+            } as O;
         }
 
-        return this._request(
-            callback, method, uri, queryParams, data, opts,
-        );
-    },
+        return this.doRequest<T, O>(callback, method, uri, queryParams, data, requestOpts);
+    }
 
     /**
      * Form and return a homeserver request URL based on the given path
@@ -607,13 +705,13 @@ MatrixHttpApi.prototype = {
      * "/_matrix/client/v2_alpha".
      * @return {string} URL
      */
-    getUrl: function(path, queryParams, prefix) {
+    public getUrl(path: string, queryParams: CoreOptions["qs"], prefix: string): string {
         let queryString = "";
         if (queryParams) {
             queryString = "?" + utils.encodeParams(queryParams);
         }
         return this.opts.baseUrl + prefix + path + queryString;
-    },
+    }
 
     /**
      * @private
@@ -640,25 +738,32 @@ MatrixHttpApi.prototype = {
      * @return {Promise} a promise which resolves to either the
      * response object (if this.opts.onlyData is truthy), or the parsed
      * body. Rejects
+     *
+     * Generic T is the callback/promise resolve type
+     * Generic O should be inferred
      */
-    _request: function(callback, method, uri, queryParams, data, opts) {
+    private doRequest<T, O extends IRequestOpts<T> = IRequestOpts<T>>(
+        callback: Callback<T>,
+        method: Method,
+        uri: string,
+        queryParams?: Record<string, string>,
+        data?: CoreOptions["body"],
+        opts?: O,
+    ): IAbortablePromise<ResponseType<T, O>> {
         if (callback !== undefined && !utils.isFunction(callback)) {
-            throw Error(
-                "Expected callback to be a function but got " + typeof callback,
-            );
+            throw Error("Expected callback to be a function but got " + typeof callback);
         }
-        opts = opts || {};
 
-        const self = this;
         if (this.opts.extraParams) {
             queryParams = {
-              ...queryParams,
-              ...this.opts.extraParams,
+                ...(queryParams || {}),
+                ...this.opts.extraParams,
             };
         }
 
         const headers = Object.assign({}, opts.headers || {});
-        const json = opts.json === undefined ? true : opts.json;
+        if (!opts) opts = {} as O;
+        const json = opts.json ?? true;
         let bodyParser = opts.bodyParser;
 
         // we handle the json encoding/decoding here, because request and
@@ -677,17 +782,17 @@ MatrixHttpApi.prototype = {
             }
 
             if (bodyParser === undefined) {
-                bodyParser = function(rawBody) {
+                bodyParser = function(rawBody: string) {
                     return JSON.parse(rawBody);
                 };
             }
         }
 
-        const defer = utils.defer();
+        const defer = utils.defer<T>();
 
-        let timeoutId;
+        let timeoutId: number;
         let timedOut = false;
-        let req;
+        let req: IRequest;
         const localTimeoutMs = opts.localTimeoutMs || this.opts.localTimeoutMs;
 
         const resetTimeout = () => {
@@ -697,9 +802,7 @@ MatrixHttpApi.prototype = {
                 }
                 timeoutId = callbacks.setTimeout(function() {
                     timedOut = true;
-                    if (req && req.abort) {
-                        req.abort();
-                    }
+                    req?.abort?.();
                     defer.reject(new MatrixError({
                         error: "Locally timed out waiting for a response",
                         errcode: "ORG.MATRIX.JSSDK_TIMEOUT",
@@ -710,7 +813,7 @@ MatrixHttpApi.prototype = {
         };
         resetTimeout();
 
-        const reqPromise = defer.promise;
+        const reqPromise = defer.promise as IAbortablePromise<ResponseType<T, O>>;
 
         try {
             req = this.opts.request(
@@ -727,7 +830,7 @@ MatrixHttpApi.prototype = {
                     headers: headers || {},
                     _matrix_opts: this.opts,
                 },
-                function(err, response, body) {
+                (err, response, body) => {
                     if (localTimeoutMs) {
                         callbacks.clearTimeout(timeoutId);
                         if (timedOut) {
@@ -735,16 +838,13 @@ MatrixHttpApi.prototype = {
                         }
                     }
 
-                    const handlerFn = requestCallback(
-                        defer, callback, self.opts.onlyData,
-                        bodyParser,
-                    );
+                    const handlerFn = requestCallback(defer, callback, this.opts.onlyData, bodyParser);
                     handlerFn(err, response, body);
                 },
             );
             if (req) {
                 // This will only work in a browser, where opts.request is the
-                // `browser-request` import. Currently `request` does not support progress
+                // `browser-request` import. Currently, `request` does not support progress
                 // updates - see https://github.com/request/request/pull/2346.
                 // `browser-request` returns an XHRHttpRequest which exposes `onprogress`
                 if ('onprogress' in req) {
@@ -757,7 +857,9 @@ MatrixHttpApi.prototype = {
 
                 // FIXME: This is EVIL, but I can't think of a better way to expose
                 // abort() operations on underlying HTTP requests :(
-                if (req.abort) reqPromise.abort = req.abort.bind(req);
+                if (req.abort) {
+                    reqPromise.abort = req.abort.bind(req);
+                }
             }
         } catch (ex) {
             defer.reject(ex);
@@ -766,8 +868,21 @@ MatrixHttpApi.prototype = {
             }
         }
         return reqPromise;
-    },
-};
+    }
+}
+
+type RequestCallback = (err?: Error, response?: XMLHttpRequest | IncomingMessage, body?: string) => void;
+
+// if using onlyData=false then wrap your expected data type in this generic
+export interface IResponse<T> {
+    code: number;
+    data: T;
+    headers?: IncomingHttpHeaders;
+}
+
+function getStatusCode(response: XMLHttpRequest | IncomingMessage): number {
+    return (response as XMLHttpRequest).status || (response as IncomingMessage).statusCode;
+}
 
 /*
  * Returns a callback that can be invoked by an HTTP request on completion,
@@ -783,17 +898,17 @@ MatrixHttpApi.prototype = {
  * response, otherwise the result object (with `code` and `data` fields)
  *
  */
-const requestCallback = function(
-    defer, userDefinedCallback, onlyData,
-    bodyParser,
-) {
-    userDefinedCallback = userDefinedCallback || function() {};
-
-    return function(err, response, body) {
+function requestCallback<T>(
+    defer: IDeferred<T>,
+    userDefinedCallback?: Callback<T>,
+    onlyData = false,
+    bodyParser?: (body: string) => T,
+): RequestCallback {
+    return function(err: Error, response: XMLHttpRequest | IncomingMessage, body: string): void {
         if (err) {
             // the unit tests use matrix-mock-request, which throw the string "aborted" when aborting a request.
             // See https://github.com/matrix-org/matrix-mock-request/blob/3276d0263a561b5b8326b47bae720578a2c7473a/src/index.js#L48
-            const aborted = err.name === "AbortError" || err === "aborted";
+            const aborted = err.name === "AbortError" || (err as any as string) === "aborted";
             if (!aborted && !(err instanceof MatrixError)) {
                 // browser-request just throws normal Error objects,
                 // not `TypeError`s like fetch does. So just assume any
@@ -801,13 +916,15 @@ const requestCallback = function(
                 err = new ConnectionError("request failed", err);
             }
         }
+
+        let data: T | string = body;
+
         if (!err) {
             try {
-                const httpStatus = response.status || response.statusCode; // XMLHttpRequest vs http.IncomingMessage
-                if (httpStatus >= 400) {
+                if (getStatusCode(response) >= 400) {
                     err = parseErrorResponse(response, body);
                 } else if (bodyParser) {
-                    body = bodyParser(body);
+                    data = bodyParser(body);
                 }
             } catch (e) {
                 err = new Error(`Error parsing server response: ${e}`);
@@ -816,21 +933,26 @@ const requestCallback = function(
 
         if (err) {
             defer.reject(err);
-            userDefinedCallback(err);
+            userDefinedCallback?.(err);
+        } else if (onlyData) {
+            defer.resolve(data as T);
+            userDefinedCallback?.(null, data as T);
         } else {
-            const res = {
-                code: response.status || response.statusCode, // XMLHttpRequest vs http.IncomingMessage
+            const res: IResponse<T> = {
+                code: getStatusCode(response),
 
                 // XXX: why do we bother with this? it doesn't work for
                 // XMLHttpRequest, so clearly we don't use it.
-                headers: response.headers,
-                data: body,
+                headers: (response as IncomingMessage).headers,
+                data: data as T,
             };
-            defer.resolve(onlyData ? body : res);
-            userDefinedCallback(null, onlyData ? body : res);
+            // XXX: the variations in caller-expected types here are horrible,
+            // typescript doesn't do conditional types based on runtime values
+            defer.resolve(res as any as T);
+            userDefinedCallback?.(null, res as any as T);
         }
     };
-};
+}
 
 /**
  * Attempt to turn an HTTP error response into a Javascript Error.
@@ -842,8 +964,8 @@ const requestCallback = function(
  * @param {String} body raw body of the response
  * @returns {Error}
  */
-function parseErrorResponse(response, body) {
-    const httpStatus = response.status || response.statusCode; // XMLHttpRequest vs http.IncomingMessage
+function parseErrorResponse(response: XMLHttpRequest | IncomingMessage, body?: string) {
+    const httpStatus = getStatusCode(response);
     const contentType = getResponseContentType(response);
 
     let err;
@@ -872,14 +994,14 @@ function parseErrorResponse(response, body) {
  * @param {XMLHttpRequest|http.IncomingMessage} response response object
  * @returns {{type: String, parameters: Object}?} parsed content-type header, or null if not found
  */
-function getResponseContentType(response) {
+function getResponseContentType(response: XMLHttpRequest | IncomingMessage): ParsedMediaType {
     let contentType;
-    if (response.getResponseHeader) {
+    if ((response as XMLHttpRequest).getResponseHeader) {
         // XMLHttpRequest provides getResponseHeader
-        contentType = response.getResponseHeader("Content-Type");
-    } else if (response.headers) {
+        contentType = (response as XMLHttpRequest).getResponseHeader("Content-Type");
+    } else if ((response as IncomingMessage).headers) {
         // request provides http.IncomingMessage which has a message.headers map
-        contentType = response.headers['content-type'] || null;
+        contentType = (response as IncomingMessage).headers['content-type'] || null;
     }
 
     if (!contentType) {
@@ -893,6 +1015,12 @@ function getResponseContentType(response) {
     }
 }
 
+interface IErrorJson extends Partial<IUsageLimit> {
+    [key: string]: any; // extensible
+    errcode?: string;
+    error?: string;
+}
+
 /**
  * Construct a Matrix error. This is a JavaScript Error with additional
  * information specific to the standard Matrix error response.
@@ -905,8 +1033,11 @@ function getResponseContentType(response) {
  * @prop {integer} httpStatus The numeric HTTP status code given
  */
 export class MatrixError extends Error {
-    constructor(errorJson) {
-        errorJson = errorJson || {};
+    public readonly errcode: string;
+    public readonly data: IErrorJson;
+    public httpStatus?: number; // set by http-api
+
+    constructor(errorJson: IErrorJson = {}) {
         super(`MatrixError: ${errorJson.errcode}`);
         this.errcode = errorJson.errcode;
         this.name = errorJson.errcode || "Unknown error code";
@@ -923,18 +1054,13 @@ export class MatrixError extends Error {
  * @constructor
  */
 export class ConnectionError extends Error {
-    constructor(message, cause = undefined) {
+    constructor(message: string, private readonly cause: Error = undefined) {
         super(message + (cause ? `: ${cause.message}` : ""));
-        this._cause = cause;
     }
 
     get name() {
         return "ConnectionError";
     }
-
-    get cause() {
-        return this._cause;
-    }
 }
 
 export class AbortError extends Error {
@@ -954,7 +1080,7 @@ export class AbortError extends Error {
  * @return {any} the result of the network operation
  * @throws {ConnectionError} If after maxAttempts the callback still throws ConnectionError
  */
-export async function retryNetworkOperation(maxAttempts, callback) {
+export async function retryNetworkOperation<T>(maxAttempts: number, callback: () => T): Promise<T> {
     let attempts = 0;
     let lastConnectionError = null;
     while (attempts < maxAttempts) {

src/interactive-auth.ts

@@ -21,7 +21,6 @@ limitations under the License.
 import { logger } from './logger';
 import { MatrixClient } from "./client";
 import { defer, IDeferred } from "./utils";
-import { MatrixError } from "./http-api";
 
 const EMAIL_STAGE_TYPE = "m.login.email.identity";
 const MSISDN_STAGE_TYPE = "m.login.msisdn";
@@ -49,7 +48,7 @@ export interface IAuthData {
     flows?: IFlow[];
     params?: Record<string, Record<string, any>>;
     errcode?: string;
-    error?: MatrixError;
+    error?: string;
 }
 
 export enum AuthType {

src/models/MSC3089Branch.ts

@@ -18,7 +18,8 @@ import { MatrixClient } from "../client";
 import { IEncryptedFile, RelationType, UNSTABLE_MSC3089_BRANCH } from "../@types/event";
 import { IContent, MatrixEvent } from "./event";
 import { MSC3089TreeSpace } from "./MSC3089TreeSpace";
-import type { ReadStream } from "fs";
+import { EventTimeline } from "./event-timeline";
+import { FileType } from "../http-api";
 
 /**
  * Represents a [MSC3089](https://github.com/matrix-org/matrix-doc/pull/3089) branch - a reference
@@ -140,7 +141,14 @@ export class MSC3089Branch {
         const room = this.client.getRoom(this.roomId);
         if (!room) throw new Error("Unknown room");
 
-        const event = room.getUnfilteredTimelineSet().findEventById(this.id);
+        let event: MatrixEvent | undefined = room.getUnfilteredTimelineSet().findEventById(this.id);
+
+        // keep scrolling back if needed until we find the event or reach the start of the room:
+        while (!event && room.getLiveTimeline().getState(EventTimeline.BACKWARDS).paginationToken) {
+            await this.client.scrollback(room, 100);
+            event = room.getUnfilteredTimelineSet().findEventById(this.id);
+        }
+
         if (!event) throw new Error("Failed to find event");
 
         // Sometimes the event isn't decrypted for us, so do that. We specifically set `emit: true`
@@ -160,7 +168,7 @@ export class MSC3089Branch {
      */
     public async createNewVersion(
         name: string,
-        encryptedContents: File | String | Buffer | ReadStream | Blob,
+        encryptedContents: FileType,
         info: Partial<IEncryptedFile>,
         additionalContent?: IContent,
     ): Promise<void> {

src/models/MSC3089TreeSpace.ts

@@ -32,7 +32,7 @@ import {
 import { MSC3089Branch } from "./MSC3089Branch";
 import { isRoomSharedHistory } from "../crypto/algorithms/megolm";
 import { ISendEventResponse } from "../@types/requests";
-import type { ReadStream } from "fs";
+import { FileType } from "../http-api";
 
 /**
  * The recommended defaults for a tree space's power levels. Note that this
@@ -282,7 +282,7 @@ export class MSC3089TreeSpace {
         const members = this.room.currentState.getStateEvents(EventType.RoomMember);
         for (const member of members) {
             const isNotUs = member.getStateKey() !== this.client.getUserId();
-            if (isNotUs && kickMemberships.includes(member.getContent<string>()['membership'])) {
+            if (isNotUs && kickMemberships.includes(member.getContent().membership)) {
                 const stateKey = member.getStateKey();
                 if (!stateKey) {
                     throw new Error("State key not found for branch");
@@ -472,7 +472,7 @@ export class MSC3089TreeSpace {
      */
     public async createFile(
         name: string,
-        encryptedContents: File | String | Buffer | ReadStream | Blob,
+        encryptedContents: FileType,
         info: Partial<IEncryptedFile>,
         additionalContent?: IContent,
     ): Promise<ISendEventResponse> {

src/models/event-timeline-set.ts

@@ -53,6 +53,11 @@ export enum DuplicateStrategy {
     Replace = "replace",
 }
 
+export interface IRoomTimelineData {
+    timeline: EventTimeline;
+    liveEvent?: boolean;
+}
+
 export class EventTimelineSet extends EventEmitter {
     private readonly timelineSupport: boolean;
     private unstableClientRelationAggregation: boolean;
@@ -209,7 +214,7 @@ export class EventTimelineSet extends EventEmitter {
      *
      * @fires module:client~MatrixClient#event:"Room.timelineReset"
      */
-    public resetLiveTimeline(backPaginationToken: string, forwardPaginationToken?: string): void {
+    public resetLiveTimeline(backPaginationToken?: string, forwardPaginationToken?: string): void {
         // Each EventTimeline has RoomState objects tracking the state at the start
         // and end of that timeline. The copies at the end of the live timeline are
         // special because they will have listeners attached to monitor changes to
@@ -594,7 +599,7 @@ export class EventTimelineSet extends EventEmitter {
         this.setRelationsTarget(event);
         this.aggregateRelations(event);
 
-        const data = {
+        const data: IRoomTimelineData = {
             timeline: timeline,
             liveEvent: !toStartOfTimeline && timeline == this.liveTimeline && !fromCache,
         };

src/models/event-timeline.ts

@@ -34,13 +34,13 @@ export class EventTimeline {
      * Symbolic constant for methods which take a 'direction' argument:
      * refers to the start of the timeline, or backwards in time.
      */
-    static BACKWARDS = Direction.Backward;
+    public static readonly BACKWARDS = Direction.Backward;
 
     /**
      * Symbolic constant for methods which take a 'direction' argument:
      * refers to the end of the timeline, or forwards in time.
      */
-    static FORWARDS = Direction.Forward;
+    public static readonly FORWARDS = Direction.Forward;
 
     /**
      * Static helper method to set sender and target properties

src/models/event.ts

@@ -1,5 +1,5 @@
 /*
-Copyright 2015 - 2021 The Matrix.org Foundation C.I.C.
+Copyright 2015 - 2022 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.
@@ -21,6 +21,7 @@ limitations under the License.
  */
 
 import { EventEmitter } from 'events';
+import { ExtensibleEvent, ExtensibleEvents, Optional } from "matrix-events-sdk";
 
 import { logger } from '../logger';
 import { VerificationRequest } from "../crypto/verification/request/VerificationRequest";
@@ -28,6 +29,7 @@ import {
     EventType,
     MsgType,
     RelationType,
+    EVENT_VISIBILITY_CHANGE_TYPE,
 } from "../@types/event";
 import { Crypto, IEventDecryptionResult } from "../crypto";
 import { deepSortedObjectEntries } from "../utils";
@@ -89,6 +91,13 @@ export interface IUnsigned {
     redacted_because?: IEvent;
     transaction_id?: string;
     invite_room_state?: StrippedState[];
+    "m.relations"?: Record<RelationType | string, any>; // No common pattern for aggregated relations
+}
+
+export interface IThreadBundledRelationship {
+    latest_event: IEvent;
+    count: number;
+    current_user_participated?: boolean;
 }
 
 export interface IEvent {
@@ -110,7 +119,7 @@ export interface IEvent {
     age?: number;
 }
 
-interface IAggregatedRelation {
+export interface IAggregatedRelation {
     origin_server_ts: number;
     event_id?: string;
     sender?: string;
@@ -122,9 +131,42 @@ interface IAggregatedRelation {
 export interface IEventRelation {
     rel_type: RelationType | string;
     event_id: string;
+    "m.in_reply_to"?: {
+        event_id: string;
+        "m.render_in"?: string[];
+    };
     key?: string;
 }
 
+export interface IVisibilityEventRelation extends IEventRelation {
+    visibility: "visible" | "hidden";
+    reason?: string;
+}
+
+/**
+ * When an event is a visibility change event, as per MSC3531,
+ * the visibility change implied by the event.
+ */
+export interface IVisibilityChange {
+    /**
+     * If `true`, the target event should be made visible.
+     * Otherwise, it should be hidden.
+     */
+    visible: boolean;
+
+    /**
+     * The event id affected.
+     */
+    eventId: string;
+
+    /**
+     * Optionally, a human-readable reason explaining why
+     * the event was hidden. Ignored if the event was made
+     * visible.
+     */
+    reason: string | null;
+}
+
 export interface IClearEvent {
     room_id?: string;
     type: string;
@@ -143,6 +185,30 @@ export interface IDecryptOptions {
     isRetry?: boolean;
 }
 
+/**
+ * Message hiding, as specified by https://github.com/matrix-org/matrix-doc/pull/3531.
+ */
+export type MessageVisibility = IMessageVisibilityHidden | IMessageVisibilityVisible;
+/**
+ * Variant of `MessageVisibility` for the case in which the message should be displayed.
+ */
+export interface IMessageVisibilityVisible {
+    readonly visible: true;
+}
+/**
+ * Variant of `MessageVisibility` for the case in which the message should be hidden.
+ */
+export interface IMessageVisibilityHidden {
+    readonly visible: false;
+    /**
+     * Optionally, a human-readable reason to show to the user indicating why the
+     * message has been hidden (e.g. "Message Pending Moderation").
+     */
+    readonly reason: string | null;
+}
+// A singleton implementing `IMessageVisibilityVisible`.
+const MESSAGE_VISIBLE: IMessageVisibilityVisible = Object.freeze({ visible: true });
+
 export class MatrixEvent extends EventEmitter {
     private pushActions: IActionsObject = null;
     private _replacingEvent: MatrixEvent = null;
@@ -150,6 +216,18 @@ export class MatrixEvent extends EventEmitter {
     private _isCancelled = false;
     private clearEvent?: IClearEvent;
 
+    /* Message hiding, as specified by https://github.com/matrix-org/matrix-doc/pull/3531.
+
+    Note: We're returning this object, so any value stored here MUST be frozen.
+    */
+    private visibility: MessageVisibility = MESSAGE_VISIBLE;
+
+    // Not all events will be extensible-event compatible, so cache a flag in
+    // addition to a falsy cached event value. We check the flag later on in
+    // a public getter to decide if the cache is valid.
+    private _hasCachedExtEv = false;
+    private _cachedExtEv: Optional<ExtensibleEvent> = undefined;
+
     /* curve25519 key which we believe belongs to the sender of the event. See
      * getSenderKey()
      */
@@ -191,6 +269,7 @@ export class MatrixEvent extends EventEmitter {
      * A reference to the thread this event belongs to
      */
     private thread: Thread = null;
+    private threadId: string;
 
     /* Set an approximate timestamp for the event relative the local clock.
      * This will inherently be approximate because it doesn't take into account
@@ -198,7 +277,7 @@ export class MatrixEvent extends EventEmitter {
      * it to us and the time we're now constructing this event, but that's better
      * than assuming the local clock is in sync with the origin HS's clock.
      */
-    private readonly localTimestamp: number;
+    public localTimestamp: number;
 
     // XXX: these should be read-only
     public sender: RoomMember = null;
@@ -263,10 +342,29 @@ export class MatrixEvent extends EventEmitter {
         });
 
         this.txnId = event.txn_id || null;
-        this.localTimestamp = Date.now() - this.getAge();
+        this.localTimestamp = Date.now() - (this.getAge() ?? 0);
         this.reEmitter = new ReEmitter(this);
     }
 
+    /**
+     * Unstable getter to try and get an extensible event. Note that this might
+     * return a falsy value if the event could not be parsed as an extensible
+     * event.
+     *
+     * @deprecated Use stable functions where possible.
+     */
+    public get unstableExtensibleEvent(): Optional<ExtensibleEvent> {
+        if (!this._hasCachedExtEv) {
+            this._cachedExtEv = ExtensibleEvents.parse(this.getEffectiveEvent());
+        }
+        return this._cachedExtEv;
+    }
+
+    private invalidateExtensibleEvent() {
+        // just reset the flag - that'll trick the getter into parsing a new event
+        this._hasCachedExtEv = false;
+    }
+
     /**
      * Gets the event as though it would appear unencrypted. If the event is already not
      * encrypted, it is simply returned as-is.
@@ -339,10 +437,10 @@ export class MatrixEvent extends EventEmitter {
     /**
      * Get the room_id for this event. This will return <code>undefined</code>
      * for <code>m.presence</code> events.
-     * @return {string} The room ID, e.g. <code>!cURbafjkfsMDVwdRDQ:matrix.org
+     * @return {string?} The room ID, e.g. <code>!cURbafjkfsMDVwdRDQ:matrix.org
      * </code>
      */
-    public getRoomId(): string {
+    public getRoomId(): string | undefined {
         return this.event.room_id;
     }
 
@@ -409,10 +507,13 @@ export class MatrixEvent extends EventEmitter {
      * @experimental
      * Get the event ID of the thread head
      */
-    public get threadRootId(): string {
+    public get threadRootId(): string | undefined {
         const relatesTo = this.getWireContent()?.["m.relates_to"];
         if (relatesTo?.rel_type === RelationType.Thread) {
             return relatesTo.event_id;
+        } else {
+            return this.threadId
+                || this.getThread()?.id;
         }
     }
 
@@ -420,17 +521,20 @@ export class MatrixEvent extends EventEmitter {
      * @experimental
      */
     public get isThreadRelation(): boolean {
-        return !!this.threadRootId;
+        return !!this.threadRootId && this.threadId !== this.getId();
     }
 
     /**
      * @experimental
      */
     public get isThreadRoot(): boolean {
-        // TODO, change the inner working of this getter for it to use the
-        // bundled relationship return on the event, view MSC3440
-        const thread = this.getThread();
-        return thread?.id === this.getId();
+        const threadDetails = this
+            .getServerAggregatedRelation<IThreadBundledRelationship>(RelationType.Thread);
+
+        // Bundled relationships only returned when the sync response is limited
+        // hence us having to check both bundled relation and inspect the thread
+        // model
+        return !!threadDetails || (this.getThread()?.id === this.getId());
     }
 
     public get parentEventId(): string {
@@ -438,8 +542,13 @@ export class MatrixEvent extends EventEmitter {
     }
 
     public get replyEventId(): string {
-        const relations = this.getWireContent()["m.relates_to"];
-        return relations?.["m.in_reply_to"]?.["event_id"];
+        // We're prefer ev.getContent() over ev.getWireContent() to make sure
+        // we grab the latest edit with potentially new relations. But we also
+        // can't just rely on ev.getContent() by itself because historically we
+        // still show the reply from the original message even though the edit
+        // event does not include the relation reply.
+        const mRelatesTo = this.getContent()['m.relates_to'] || this.getWireContent()['m.relates_to'];
+        return mRelatesTo?.['m.in_reply_to']?.event_id;
     }
 
     public get relationEventId(): string {
@@ -475,9 +584,10 @@ export class MatrixEvent extends EventEmitter {
      * Get the age of this event. This represents the age of the event when the
      * event arrived at the device, and not the age of the event when this
      * function was called.
-     * @return {Number} The age of this event in milliseconds.
+     * Can only be returned once the server has echo'ed back
+     * @return {Number|undefined} The age of this event in milliseconds.
      */
-    public getAge(): number {
+    public getAge(): number | undefined {
         return this.getUnsigned().age || this.event.age; // v2 / v1
     }
 
@@ -570,7 +680,12 @@ export class MatrixEvent extends EventEmitter {
     }
 
     public shouldAttemptDecryption() {
-        return this.isEncrypted() && !this.isBeingDecrypted() && !this.clearEvent;
+        if (this.isRedacted()) return false;
+        if (this.isBeingDecrypted()) return false;
+        if (this.clearEvent) return false;
+        if (!this.isEncrypted()) return false;
+
+        return true;
     }
 
     /**
@@ -771,7 +886,7 @@ export class MatrixEvent extends EventEmitter {
     private badEncryptedMessage(reason: string): IEventDecryptionResult {
         return {
             clearEvent: {
-                type: "m.room.message",
+                type: EventType.RoomMessage,
                 content: {
                     msgtype: "m.bad.encrypted",
                     body: "** Unable to decrypt: " + reason + " **",
@@ -801,6 +916,7 @@ export class MatrixEvent extends EventEmitter {
         this.forwardingCurve25519KeyChain =
             decryptionResult.forwardingCurve25519KeyChain || [];
         this.untrusted = decryptionResult.untrusted || false;
+        this.invalidateExtensibleEvent();
     }
 
     /**
@@ -818,7 +934,7 @@ export class MatrixEvent extends EventEmitter {
      * @return {boolean} True if this event is encrypted.
      */
     public isEncrypted(): boolean {
-        return !this.isState() && this.event.type === "m.room.encrypted";
+        return !this.isState() && this.event.type === EventType.RoomMessageEncrypted;
     }
 
     /**
@@ -904,6 +1020,10 @@ export class MatrixEvent extends EventEmitter {
         return this.event.unsigned || {};
     }
 
+    public setUnsigned(unsigned: IUnsigned): void {
+        this.event.unsigned = unsigned;
+    }
+
     public unmarkLocallyRedacted(): boolean {
         const value = this._localRedactionEvent;
         this._localRedactionEvent = null;
@@ -923,6 +1043,53 @@ export class MatrixEvent extends EventEmitter {
         this.event.unsigned.redacted_because = redactionEvent.event as IEvent;
     }
 
+    /**
+     * Change the visibility of an event, as per https://github.com/matrix-org/matrix-doc/pull/3531 .
+     *
+     * @fires module:models/event.MatrixEvent#"Event.visibilityChange" if `visibilityEvent`
+     *   caused a change in the actual visibility of this event, either by making it
+     *   visible (if it was hidden), by making it hidden (if it was visible) or by
+     *   changing the reason (if it was hidden).
+     * @param visibilityEvent event holding a hide/unhide payload, or nothing
+     *   if the event is being reset to its original visibility (presumably
+     *   by a visibility event being redacted).
+     */
+    public applyVisibilityEvent(visibilityChange?: IVisibilityChange): void {
+        const visible = visibilityChange ? visibilityChange.visible : true;
+        const reason = visibilityChange ? visibilityChange.reason : null;
+        let change = false;
+        if (this.visibility.visible !== visibilityChange.visible) {
+            change = true;
+        } else if (!this.visibility.visible && this.visibility["reason"] !== reason) {
+            change = true;
+        }
+        if (change) {
+            if (visible) {
+                this.visibility = MESSAGE_VISIBLE;
+            } else {
+                this.visibility = Object.freeze({
+                    visible: false,
+                    reason: reason,
+                });
+            }
+            if (change) {
+                this.emit("Event.visibilityChange", this, visible);
+            }
+        }
+    }
+
+    /**
+     * Return instructions to display or hide the message.
+     *
+     * @returns Instructions determining whether the message
+     * should be displayed.
+     */
+    public messageVisibility(): MessageVisibility {
+        // Note: We may return `this.visibility` without fear, as
+        // this is a shallow frozen object.
+        return this.visibility;
+    }
+
     /**
      * Update the content of an event in the same way it would be by the server
      * if it were redacted before it was sent to us
@@ -972,6 +1139,8 @@ export class MatrixEvent extends EventEmitter {
                 delete content[key];
             }
         }
+
+        this.invalidateExtensibleEvent();
     }
 
     /**
@@ -989,7 +1158,55 @@ export class MatrixEvent extends EventEmitter {
      * @return {boolean} True if this event is a redaction
      */
     public isRedaction(): boolean {
-        return this.getType() === "m.room.redaction";
+        return this.getType() === EventType.RoomRedaction;
+    }
+
+    /**
+     * Return the visibility change caused by this event,
+     * as per https://github.com/matrix-org/matrix-doc/pull/3531.
+     *
+     * @returns If the event is a well-formed visibility change event,
+     * an instance of `IVisibilityChange`, otherwise `null`.
+     */
+    public asVisibilityChange(): IVisibilityChange | null {
+        if (!EVENT_VISIBILITY_CHANGE_TYPE.matches(this.getType())) {
+            // Not a visibility change event.
+            return null;
+        }
+        const relation = this.getRelation();
+        if (!relation || relation.rel_type != "m.reference") {
+            // Ill-formed, ignore this event.
+            return null;
+        }
+        const eventId = relation.event_id;
+        if (!eventId) {
+            // Ill-formed, ignore this event.
+            return null;
+        }
+        const content = this.getWireContent();
+        const visible = !!content.visible;
+        const reason = content.reason;
+        if (reason && typeof reason != "string") {
+            // Ill-formed, ignore this event.
+            return null;
+        }
+        // Well-formed visibility change event.
+        return {
+            visible,
+            reason,
+            eventId,
+        };
+    }
+
+    /**
+     * Check if this event alters the visibility of another event,
+     * as per https://github.com/matrix-org/matrix-doc/pull/3531.
+     *
+     * @returns {boolean} True if this event alters the visibility
+     * of another event.
+     */
+    public isVisibilityEvent(): boolean {
+        return EVENT_VISIBILITY_CHANGE_TYPE.matches(this.getType());
     }
 
     /**
@@ -1053,6 +1270,8 @@ export class MatrixEvent extends EventEmitter {
             // emit the event if it changed
             this.emit("Event.localEventIdReplaced", this);
         }
+
+        this.localTimestamp = Date.now() - this.getAge();
     }
 
     /**
@@ -1127,6 +1346,7 @@ export class MatrixEvent extends EventEmitter {
         if (this._replacingEvent !== newEvent) {
             this._replacingEvent = newEvent;
             this.emit("Event.replaced", this);
+            this.invalidateExtensibleEvent();
         }
     }
 
@@ -1146,11 +1366,8 @@ export class MatrixEvent extends EventEmitter {
         return this.status;
     }
 
-    public getServerAggregatedRelation(relType: RelationType): IAggregatedRelation {
-        const relations = this.getUnsigned()["m.relations"];
-        if (relations) {
-            return relations[relType];
-        }
+    public getServerAggregatedRelation<T>(relType: RelationType): T | undefined {
+        return this.getUnsigned()["m.relations"]?.[relType];
     }
 
     /**
@@ -1159,7 +1376,7 @@ export class MatrixEvent extends EventEmitter {
      * @return {string?}
      */
     public replacingEventId(): string | undefined {
-        const replaceRelation = this.getServerAggregatedRelation(RelationType.Replace);
+        const replaceRelation = this.getServerAggregatedRelation<IAggregatedRelation>(RelationType.Replace);
         if (replaceRelation) {
             return replaceRelation.event_id;
         } else if (this._replacingEvent) {
@@ -1184,7 +1401,7 @@ export class MatrixEvent extends EventEmitter {
      * @return {Date?}
      */
     public replacingEventDate(): Date | undefined {
-        const replaceRelation = this.getServerAggregatedRelation(RelationType.Replace);
+        const replaceRelation = this.getServerAggregatedRelation<IAggregatedRelation>(RelationType.Replace);
         if (replaceRelation) {
             const ts = replaceRelation.origin_server_ts;
             if (Number.isFinite(ts)) {
@@ -1350,9 +1567,13 @@ export class MatrixEvent extends EventEmitter {
     /**
      * @experimental
      */
-    public getThread(): Thread {
+    public getThread(): Thread | undefined {
         return this.thread;
     }
+
+    public setThreadId(threadId: string): void {
+        this.threadId = threadId;
+    }
 }
 
 /* REDACT_KEEP_KEYS gives the keys we keep when an event is redacted
@@ -1371,15 +1592,15 @@ const REDACT_KEEP_KEYS = new Set([
 
 // a map from event type to the .content keys we keep when an event is redacted
 const REDACT_KEEP_CONTENT_MAP = {
-    'm.room.member': { 'membership': 1 },
-    'm.room.create': { 'creator': 1 },
-    'm.room.join_rules': { 'join_rule': 1 },
-    'm.room.power_levels': {
+    [EventType.RoomMember]: { 'membership': 1 },
+    [EventType.RoomCreate]: { 'creator': 1 },
+    [EventType.RoomJoinRules]: { 'join_rule': 1 },
+    [EventType.RoomPowerLevels]: {
         'ban': 1, 'events': 1, 'events_default': 1,
         'kick': 1, 'redact': 1, 'state_default': 1,
         'users': 1, 'users_default': 1,
     },
-    'm.room.aliases': { 'aliases': 1 },
+    [EventType.RoomAliases]: { 'aliases': 1 },
 };
 
 /**

src/models/related-relations.ts

@@ -0,0 +1,38 @@
+/*
+Copyright 2022 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 { Relations } from "./relations";
+import { MatrixEvent } from "./event";
+
+export class RelatedRelations {
+    private relations: Relations[];
+
+    public constructor(relations: Relations[]) {
+        this.relations = relations.filter(r => !!r);
+    }
+
+    public getRelations(): MatrixEvent[] {
+        return this.relations.reduce((c, p) => [...c, ...p.getRelations()], []);
+    }
+
+    public on(ev: string, fn: (...params) => void) {
+        this.relations.forEach(r => r.on(ev, fn));
+    }
+
+    public off(ev: string, fn: (...params) => void) {
+        this.relations.forEach(r => r.off(ev, fn));
+    }
+}

src/models/relations.ts

@@ -16,7 +16,7 @@ limitations under the License.
 
 import { EventEmitter } from 'events';
 
-import { EventStatus, MatrixEvent } from './event';
+import { EventStatus, MatrixEvent, IAggregatedRelation } from './event';
 import { Room } from './room';
 import { logger } from '../logger';
 import { RelationType } from "../@types/event";
@@ -319,7 +319,7 @@ export class Relations extends EventEmitter {
 
         // the all-knowning server tells us that the event at some point had
         // this timestamp for its replacement, so any following replacement should definitely not be less
-        const replaceRelation = this.targetEvent.getServerAggregatedRelation(RelationType.Replace);
+        const replaceRelation = this.targetEvent.getServerAggregatedRelation<IAggregatedRelation>(RelationType.Replace);
         const minTs = replaceRelation && replaceRelation.origin_server_ts;
 
         const lastReplacement = this.getRelations().reduce((last, event) => {

src/models/room-state.ts

@@ -618,14 +618,14 @@ export class RoomState extends EventEmitter {
     }
 
     /**
-     * Returns true if the given MatrixClient has permission to send a state
-     * event of type `stateEventType` into this room.
-     * @param {string} stateEventType The type of state events to test
-     * @param {MatrixClient} cli The client to test permission for
-     * @return {boolean} true if the given client should be permitted to send
-     *                        the given type of state event into this room,
-     *                        according to the room's state.
-     */
+      * Returns true if the given MatrixClient has permission to send a state
+      * event of type `stateEventType` into this room.
+      * @param {string} stateEventType The type of state events to test
+      * @param {MatrixClient} cli The client to test permission for
+      * @return {boolean} true if the given client should be permitted to send
+      *                        the given type of state event into this room,
+      *                        according to the room's state.
+      */
     public mayClientSendStateEvent(stateEventType: EventType | string, cli: MatrixClient): boolean {
         if (cli.isGuest()) {
             return false;

src/models/room.ts

@@ -21,7 +21,7 @@ limitations under the License.
 import { EventEmitter } from "events";
 
 import { EventTimelineSet, DuplicateStrategy } from "./event-timeline-set";
-import { EventTimeline } from "./event-timeline";
+import { Direction, EventTimeline } from "./event-timeline";
 import { getHttpUriForMxc } from "../content-repo";
 import * as utils from "../utils";
 import { normalize } from "../utils";
@@ -30,12 +30,16 @@ import { RoomMember } from "./room-member";
 import { IRoomSummary, RoomSummary } from "./room-summary";
 import { logger } from '../logger';
 import { ReEmitter } from '../ReEmitter';
-import { EventType, RoomCreateTypeField, RoomType, UNSTABLE_ELEMENT_FUNCTIONAL_USERS } from "../@types/event";
+import {
+    EventType, RoomCreateTypeField, RoomType, UNSTABLE_ELEMENT_FUNCTIONAL_USERS,
+    EVENT_VISIBILITY_CHANGE_TYPE,
+} from "../@types/event";
 import { IRoomVersionsCapability, MatrixClient, PendingEventOrdering, RoomVersionStability } from "../client";
 import { GuestAccess, HistoryVisibility, JoinRule, ResizeMethod } from "../@types/partials";
 import { Filter } from "../filter";
 import { RoomState } from "./room-state";
 import { Thread, ThreadEvent } from "./thread";
+import { Method } from "../http-api";
 
 // 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
@@ -92,7 +96,7 @@ interface ICachedReceipt {
     data: IReceipt;
 }
 
-type ReceiptCache = Record<string, ICachedReceipt[]>;
+type ReceiptCache = {[eventId: string]: ICachedReceipt[]};
 
 interface IReceiptContent {
     [eventId: string]: {
@@ -102,13 +106,43 @@ interface IReceiptContent {
     };
 }
 
-type Receipts = Record<string, Record<string, IWrappedReceipt>>;
+const ReceiptPairRealIndex = 0;
+const ReceiptPairSyntheticIndex = 1;
+// We will only hold a synthetic receipt if we do not have a real receipt or the synthetic is newer.
+type Receipts = {
+    [receiptType: string]: {
+        [userId: string]: [IWrappedReceipt, IWrappedReceipt]; // Pair<real receipt, synthetic receipt> (both nullable)
+    };
+};
+
+// When inserting a visibility event affecting event `eventId`, we
+// need to scan through existing visibility events for `eventId`.
+// In theory, this could take an unlimited amount of time if:
+//
+// - the visibility event was sent by a moderator; and
+// - `eventId` already has many visibility changes (usually, it should
+//   be 2 or less); and
+// - for some reason, the visibility changes are received out of order
+//   (usually, this shouldn't happen at all).
+//
+// For this reason, we limit the number of events to scan through,
+// expecting that a broken visibility change for a single event in
+// an extremely uncommon case (possibly a DoS) is a small
+// price to pay to keep matrix-js-sdk responsive.
+const MAX_NUMBER_OF_VISIBILITY_EVENTS_TO_SCAN_THROUGH = 30;
 
 export enum NotificationCountType {
     Highlight = "highlight",
     Total = "total",
 }
 
+export interface ICreateFilterOpts {
+    // Populate the filtered timeline with already loaded events in the room
+    // timeline. Useful to disable for some filters that can't be achieved by the
+    // client in an efficient manner
+    prepopulateTimeline?: boolean;
+}
+
 export class Room extends EventEmitter {
     private readonly reEmitter: ReEmitter;
     private txnToEvent: Record<string, MatrixEvent> = {}; // Pending in-flight requests { string: MatrixEvent }
@@ -118,8 +152,6 @@ export class Room extends EventEmitter {
     // a pre-cached list for this purpose.
     private receipts: Receipts = {}; // { receipt_type: { user_id: IReceipt } }
     private receiptCacheByEventId: ReceiptCache = {}; // { event_id: IReceipt2[] }
-    // only receipts that came from the server, not synthesized ones
-    private realReceipts: Receipts = {};
     private notificationCounts: Partial<Record<NotificationCountType, number>> = {};
     private readonly timelineSets: EventTimelineSet[];
     // any filtered timeline sets we're maintaining for this room
@@ -135,21 +167,74 @@ export class Room extends EventEmitter {
     private membersPromise?: Promise<boolean>;
 
     // XXX: These should be read-only
+    /**
+     * The human-readable display name for this room.
+     */
     public name: string;
+    /**
+     * The un-homoglyphed name for this room.
+     */
     public normalizedName: string;
+    /**
+     * Dict of room tags; the keys are the tag name and the values
+     * are any metadata associated with the tag - e.g. { "fav" : { order: 1 } }
+     */
     public tags: Record<string, Record<string, any>> = {}; // $tagName: { $metadata: $value }
+    /**
+     * accountData Dict of per-room account_data events; the keys are the
+     * event type and the values are the events.
+     */
     public accountData: Record<string, MatrixEvent> = {}; // $eventType: $event
+    /**
+     * The room summary.
+     */
     public summary: RoomSummary = null;
+    /**
+     * A token which a data store can use to remember the state of the room.
+     */
     public readonly storageToken?: string;
     // legacy fields
+    /**
+     * The live event timeline for this room, with the oldest event at index 0.
+     * Present for backwards compatibility - prefer getLiveTimeline().getEvents()
+     */
     public timeline: MatrixEvent[];
+    /**
+     * oldState The state of the room at the time of the oldest
+     * event in the live timeline. Present for backwards compatibility -
+     * prefer getLiveTimeline().getState(EventTimeline.BACKWARDS).
+     */
     public oldState: RoomState;
+    /**
+     * currentState The state of the room at the time of the
+     * newest event in the timeline. Present for backwards compatibility -
+     * prefer getLiveTimeline().getState(EventTimeline.FORWARDS).
+     */
     public currentState: RoomState;
 
     /**
      * @experimental
      */
     public threads = new Map<string, Thread>();
+    public lastThread: Thread;
+
+    /**
+     * A mapping of eventId to all visibility changes to apply
+     * to the event, by chronological order, as per
+     * https://github.com/matrix-org/matrix-doc/pull/3531
+     *
+     * # Invariants
+     *
+     * - within each list, all events are classed by
+     *   chronological order;
+     * - all events are events such that
+     *  `asVisibilityEvent()` returns a non-null `IVisibilityChange`;
+     * - within each list with key `eventId`, all events
+     *   are in relation to `eventId`.
+     *
+     * @experimental
+     */
+    private visibilityEvents = new Map<string, MatrixEvent[]>();
 
     /**
      * Construct a new Room.
@@ -191,26 +276,6 @@ export class Room extends EventEmitter {
      * Optional. Set to true to enable client-side aggregation of event relations
      * via `EventTimelineSet#getRelationsForEvent`.
      * This feature is currently unstable and the API may change without notice.
-     *
-     * @prop {string} roomId The ID of this room.
-     * @prop {string} name The human-readable display name for this room.
-     * @prop {string} normalizedName The un-homoglyphed name for this room.
-     * @prop {Array<MatrixEvent>} timeline The live event timeline for this room,
-     * with the oldest event at index 0. Present for backwards compatibility -
-     * prefer getLiveTimeline().getEvents().
-     * @prop {object} tags Dict of room tags; the keys are the tag name and the values
-     * are any metadata associated with the tag - e.g. { "fav" : { order: 1 } }
-     * @prop {object} accountData Dict of per-room account_data events; the keys are the
-     * event type and the values are the events.
-     * @prop {RoomState} oldState The state of the room at the time of the oldest
-     * event in the live timeline. Present for backwards compatibility -
-     * prefer getLiveTimeline().getState(EventTimeline.BACKWARDS).
-     * @prop {RoomState} currentState The state of the room at the time of the
-     * newest event in the timeline. Present for backwards compatibility -
-     * prefer getLiveTimeline().getState(EventTimeline.FORWARDS).
-     * @prop {RoomSummary} summary The room summary.
-     * @prop {*} storageToken A token which a data store can use to remember
-     * the state of the room.
      */
     constructor(
         public readonly roomId: string,
@@ -231,7 +296,9 @@ export class Room extends EventEmitter {
         // all our per-room timeline sets. the first one is the unfiltered ones;
         // the subsequent ones are the filtered ones in no particular order.
         this.timelineSets = [new EventTimelineSet(this, opts)];
-        this.reEmitter.reEmit(this.getUnfilteredTimelineSet(), ["Room.timeline", "Room.timelineReset"]);
+        this.reEmitter.reEmit(this.getUnfilteredTimelineSet(), [
+            "Room.timeline", "Room.timelineReset",
+        ]);
 
         this.fixUpLegacyTimelineFields();
 
@@ -660,7 +727,7 @@ export class Room extends EventEmitter {
         const path = utils.encodeUri("/rooms/$roomId/members?" + queryString,
             { $roomId: this.roomId });
         const http = this.client.http;
-        const response = await http.authedRequest(undefined, "GET", path);
+        const response = await http.authedRequest<{ chunk: IEvent[] }>(undefined, Method.Get, path);
         return response.chunk;
     }
 
@@ -778,7 +845,7 @@ export class Room extends EventEmitter {
      * timeline which would otherwise be unable to paginate forwards without this token).
      * Removing just the old live timeline whilst preserving previous ones is not supported.
      */
-    public resetLiveTimeline(backPaginationToken: string, forwardPaginationToken: string): void {
+    public resetLiveTimeline(backPaginationToken: string | null, forwardPaginationToken: string | null): void {
         for (let i = 0; i < this.timelineSets.length; i++) {
             this.timelineSets[i].resetLiveTimeline(
                 backPaginationToken, forwardPaginationToken,
@@ -1207,9 +1274,14 @@ export class Room extends EventEmitter {
     /**
      * Add a timelineSet for this room with the given filter
      * @param {Filter} filter The filter to be applied to this timelineSet
+     * @param {Object=} opts Configuration options
+     * @param {*} opts.storageToken Optional.
      * @return {EventTimelineSet} The timelineSet
      */
-    public getOrCreateFilteredTimelineSet(filter: Filter): EventTimelineSet {
+    public getOrCreateFilteredTimelineSet(
+        filter: Filter,
+        { prepopulateTimeline = true }: ICreateFilterOpts = {},
+    ): EventTimelineSet {
         if (this.filteredTimelineSets[filter.filterId]) {
             return this.filteredTimelineSets[filter.filterId];
         }
@@ -1219,30 +1291,39 @@ export class Room extends EventEmitter {
         this.filteredTimelineSets[filter.filterId] = timelineSet;
         this.timelineSets.push(timelineSet);
 
-        // populate up the new timelineSet with filtered events from our live
-        // unfiltered timeline.
-        //
-        // XXX: This is risky as our timeline
-        // may have grown huge and so take a long time to filter.
-        // see https://github.com/vector-im/vector-web/issues/2109
-
         const unfilteredLiveTimeline = this.getLiveTimeline();
+        // Not all filter are possible to replicate client-side only
+        // When that's the case we do not want to prepopulate from the live timeline
+        // as we would get incorrect results compared to what the server would send back
+        if (prepopulateTimeline) {
+            // populate up the new timelineSet with filtered events from our live
+            // unfiltered timeline.
+            //
+            // XXX: This is risky as our timeline
+            // may have grown huge and so take a long time to filter.
+            // see https://github.com/vector-im/vector-web/issues/2109
 
-        unfilteredLiveTimeline.getEvents().forEach(function(event) {
-            timelineSet.addLiveEvent(event);
-        });
+            unfilteredLiveTimeline.getEvents().forEach(function(event) {
+                timelineSet.addLiveEvent(event);
+            });
 
-        // find the earliest unfiltered timeline
-        let timeline = unfilteredLiveTimeline;
-        while (timeline.getNeighbouringTimeline(EventTimeline.BACKWARDS)) {
-            timeline = timeline.getNeighbouringTimeline(EventTimeline.BACKWARDS);
+            // find the earliest unfiltered timeline
+            let timeline = unfilteredLiveTimeline;
+            while (timeline.getNeighbouringTimeline(EventTimeline.BACKWARDS)) {
+                timeline = timeline.getNeighbouringTimeline(EventTimeline.BACKWARDS);
+            }
+
+            timelineSet.getLiveTimeline().setPaginationToken(
+                timeline.getPaginationToken(EventTimeline.BACKWARDS),
+                EventTimeline.BACKWARDS,
+            );
+        } else {
+            const livePaginationToken = unfilteredLiveTimeline.getPaginationToken(Direction.Forward);
+            timelineSet
+                .getLiveTimeline()
+                .setPaginationToken(livePaginationToken, Direction.Backward);
         }
 
-        timelineSet.getLiveTimeline().setPaginationToken(
-            timeline.getPaginationToken(EventTimeline.BACKWARDS),
-            EventTimeline.BACKWARDS,
-        );
-
         // alternatively, we could try to do something like this to try and re-paginate
         // in the filtered events from nothing, but Mark says it's an abuse of the API
         // to do so:
@@ -1268,7 +1349,7 @@ export class Room extends EventEmitter {
         }
     }
 
-    public findThreadForEvent(event: MatrixEvent): Thread {
+    public findThreadForEvent(event: MatrixEvent): Thread | null {
         if (!event) {
             return null;
         }
@@ -1296,15 +1377,24 @@ export class Room extends EventEmitter {
             let rootEvent = this.findEventById(event.threadRootId);
             // If the rootEvent does not exist in the current sync, then look for
             // it over the network
-            if (!rootEvent) {
-                const eventData = await this.client.fetchRoomEvent(this.roomId, event.threadRootId);
-                rootEvent = new MatrixEvent(eventData);
+            try {
+                let eventData;
+                if (event.threadRootId) {
+                    eventData = await this.client.fetchRoomEvent(this.roomId, event.threadRootId);
+                }
+
+                if (!rootEvent) {
+                    rootEvent = new MatrixEvent(eventData);
+                } else {
+                    rootEvent.setUnsigned(eventData.unsigned);
+                }
+            } finally {
+                // The root event might be not be visible to the person requesting
+                // it. If it wasn't fetched successfully the thread will work
+                // in "limited" mode and won't benefit from all the APIs a homeserver
+                // can provide to enhance the thread experience
+                thread = this.createThread(rootEvent, events);
             }
-            events.unshift(rootEvent);
-            thread = new Thread(events, this, this.client);
-            this.threads.set(thread.id, thread);
-            this.reEmitter.reEmit(thread, [ThreadEvent.Update, ThreadEvent.Ready]);
-            this.emit(ThreadEvent.New, thread);
         }
 
         if (event.getUnsigned().transaction_id) {
@@ -1319,6 +1409,32 @@ export class Room extends EventEmitter {
         this.emit(ThreadEvent.Update, thread);
     }
 
+    public createThread(rootEvent: MatrixEvent, events?: MatrixEvent[]): Thread | undefined {
+        const thread = new Thread(rootEvent, {
+            initialEvents: events,
+            room: this,
+            client: this.client,
+        });
+        // If we managed to create a thread and figure out its `id`
+        // then we can use it
+        if (thread.id) {
+            this.threads.set(thread.id, thread);
+            this.reEmitter.reEmit(thread, [
+                ThreadEvent.Update,
+                ThreadEvent.Ready,
+                "Room.timeline",
+                "Room.timelineReset",
+            ]);
+
+            if (!this.lastThread || this.lastThread.rootEvent.localTimestamp < rootEvent.localTimestamp) {
+                this.lastThread = thread;
+            }
+
+            this.emit(ThreadEvent.New, thread);
+            return thread;
+        }
+    }
+
     /**
      * Add an event to the end of this room's live timelines. Will fire
      * "Room.timeline".
@@ -1356,6 +1472,15 @@ export class Room extends EventEmitter {
                 // (in the sender and target fields). We should get those
                 // RoomMember objects to update themselves when the events that
                 // they are based on are changed.
+
+                // Remove any visibility change on this event.
+                this.visibilityEvents.delete(redactId);
+
+                // If this event is a visibility change event, remove it from the
+                // list of visibility changes and update any event affected by it.
+                if (redactedEvent.isVisibilityEvent()) {
+                    this.redactVisibilityChangeEvent(event);
+                }
             }
 
             // FIXME: apply redactions to notification list
@@ -1365,6 +1490,15 @@ export class Room extends EventEmitter {
             // this may be needed to trigger an update.
         }
 
+        // Implement MSC3531: hiding messages.
+        if (event.isVisibilityEvent()) {
+            // This event changes the visibility of another event, record
+            // the visibility change, inform clients if necessary.
+            this.applyNewVisibilityEvent(event);
+        }
+        // If any pending visibility change is waiting for this (older) event,
+        this.applyPendingVisibilityEvents(event);
+
         if (event.getUnsigned().transaction_id) {
             const existingEvent = this.txnToEvent[event.getUnsigned().transaction_id];
             if (existingEvent) {
@@ -1431,7 +1565,7 @@ export class Room extends EventEmitter {
         EventTimeline.setEventMetadata(event, this.getLiveTimeline().getState(EventTimeline.FORWARDS), false);
 
         this.txnToEvent[txnId] = event;
-        const thread = this.threads.get(event.threadRootId);
+        const thread = this.findThreadForEvent(event);
         if (this.opts.pendingEventOrdering === PendingEventOrdering.Detached && !thread) {
             if (this.pendingEventList.some((e) => e.status === EventStatus.NOT_SENT)) {
                 logger.warn("Setting event as NOT_SENT due to messages in the same state");
@@ -1460,8 +1594,7 @@ export class Room extends EventEmitter {
             }
         } else {
             if (thread) {
-                thread.timelineSet.addEventToTimeline(event,
-                    thread.timelineSet.getLiveTimeline(), false);
+                thread.addEvent(event, false);
             } else {
                 for (let i = 0; i < this.timelineSets.length; i++) {
                     const timelineSet = this.timelineSets[i];
@@ -1586,7 +1719,7 @@ export class Room extends EventEmitter {
         // any, which is good, because we don't want to try decoding it again).
         localEvent.handleRemoteEcho(remoteEvent.event);
 
-        const thread = this.threads.get(remoteEvent.threadRootId);
+        const thread = this.findThreadForEvent(remoteEvent);
         if (thread) {
             thread.timelineSet.handleRemoteEcho(localEvent, oldEventId, newEventId);
         } else {
@@ -1747,7 +1880,7 @@ export class Room extends EventEmitter {
             // TODO: We should have a filter to say "only add state event
             // types X Y Z to the timeline".
             this.addLiveEvent(events[i], duplicateStrategy, fromCache);
-            const thread = this.threads.get(events[i].getId());
+            const thread = this.findThreadForEvent(events[i]);
             if (thread) {
                 thread.addEvent(events[i], true);
             }
@@ -1853,19 +1986,12 @@ export class Room extends EventEmitter {
     }
 
     public getReadReceiptForUserId(userId: string, ignoreSynthesized = false): IWrappedReceipt | null {
-        let receipts = this.receipts;
+        const [realReceipt, syntheticReceipt] = this.receipts["m.read"]?.[userId] ?? [];
         if (ignoreSynthesized) {
-            receipts = this.realReceipts;
+            return realReceipt;
         }
 
-        if (
-            receipts["m.read"] === undefined ||
-            receipts["m.read"][userId] === undefined
-        ) {
-            return null;
-        }
-
-        return receipts["m.read"][userId];
+        return syntheticReceipt ?? realReceipt;
     }
 
     /**
@@ -1929,84 +2055,115 @@ export class Room extends EventEmitter {
     /**
      * Add a receipt event to the room.
      * @param {MatrixEvent} event The m.receipt event.
-     * @param {Boolean} fake True if this event is implicit
+     * @param {Boolean} synthetic True if this event is implicit.
      */
-    public addReceipt(event: MatrixEvent, fake = false): void {
-        if (!fake) {
-            this.addReceiptsToStructure(event, this.realReceipts);
-            // we don't bother caching real receipts by event ID
-            // as there's nothing that would read it.
-        }
-        this.addReceiptsToStructure(event, this.receipts);
-        this.receiptCacheByEventId = this.buildReceiptCache(this.receipts);
-
-        // send events after we've regenerated the cache, otherwise things that
-        // listened for the event would read from a stale cache
+    public addReceipt(event: MatrixEvent, synthetic = false): void {
+        this.addReceiptsToStructure(event, synthetic);
+        // send events after we've regenerated the structure & cache, otherwise things that
+        // listened for the event would read stale data.
         this.emit("Room.receipt", event, this);
     }
 
     /**
      * Add a receipt event to the room.
      * @param {MatrixEvent} event The m.receipt event.
-     * @param {Object} receipts The object to add receipts to
+     * @param {Boolean} synthetic True if this event is implicit.
      */
-    private addReceiptsToStructure(event: MatrixEvent, receipts: Receipts): void {
+    private addReceiptsToStructure(event: MatrixEvent, synthetic: boolean): void {
         const content = event.getContent<IReceiptContent>();
         Object.keys(content).forEach((eventId) => {
             Object.keys(content[eventId]).forEach((receiptType) => {
                 Object.keys(content[eventId][receiptType]).forEach((userId) => {
                     const receipt = content[eventId][receiptType][userId];
 
-                    if (!receipts[receiptType]) {
-                        receipts[receiptType] = {};
+                    if (!this.receipts[receiptType]) {
+                        this.receipts[receiptType] = {};
+                    }
+                    if (!this.receipts[receiptType][userId]) {
+                        this.receipts[receiptType][userId] = [null, null];
                     }
 
-                    const existingReceipt = receipts[receiptType][userId];
+                    const pair = this.receipts[receiptType][userId];
 
-                    if (!existingReceipt) {
-                        receipts[receiptType][userId] = {} as IWrappedReceipt;
-                    } else {
-                        // we only want to add this receipt if we think it is later
-                        // than the one we already have. (This is managed
-                        // server-side, but because we synthesize RRs locally we
-                        // have to do it here too.)
+                    let existingReceipt = pair[ReceiptPairRealIndex];
+                    if (synthetic) {
+                        existingReceipt = pair[ReceiptPairSyntheticIndex] ?? pair[ReceiptPairRealIndex];
+                    }
+
+                    if (existingReceipt) {
+                        // we only want to add this receipt if we think it is later than the one we already have.
+                        // This is managed server-side, but because we synthesize RRs locally we have to do it here too.
                         const ordering = this.getUnfilteredTimelineSet().compareEventOrdering(
-                            existingReceipt.eventId, eventId);
+                            existingReceipt.eventId,
+                            eventId,
+                        );
                         if (ordering !== null && ordering >= 0) {
                             return;
                         }
                     }
 
-                    receipts[receiptType][userId] = {
-                        eventId: eventId,
+                    const wrappedReceipt: IWrappedReceipt = {
+                        eventId,
                         data: receipt,
                     };
-                });
-            });
-        });
-    }
 
-    /**
-     * Build and return a map of receipts by event ID
-     * @param {Object} receipts A map of receipts
-     * @return {Object} Map of receipts by event ID
-     */
-    private buildReceiptCache(receipts: Receipts): ReceiptCache {
-        const receiptCacheByEventId: ReceiptCache = {};
-        Object.keys(receipts).forEach(function(receiptType) {
-            Object.keys(receipts[receiptType]).forEach(function(userId) {
-                const receipt = receipts[receiptType][userId];
-                if (!receiptCacheByEventId[receipt.eventId]) {
-                    receiptCacheByEventId[receipt.eventId] = [];
-                }
-                receiptCacheByEventId[receipt.eventId].push({
-                    userId: userId,
-                    type: receiptType,
-                    data: receipt.data,
+                    const realReceipt = synthetic ? pair[ReceiptPairRealIndex] : wrappedReceipt;
+                    const syntheticReceipt = synthetic ? wrappedReceipt : pair[ReceiptPairSyntheticIndex];
+
+                    let ordering: number | null = null;
+                    if (realReceipt && syntheticReceipt) {
+                        ordering = this.getUnfilteredTimelineSet().compareEventOrdering(
+                            realReceipt.eventId,
+                            syntheticReceipt.eventId,
+                        );
+                    }
+
+                    const preferSynthetic = ordering === null || ordering < 0;
+
+                    // we don't bother caching just real receipts by event ID as there's nothing that would read it.
+                    // Take the current cached receipt before we overwrite the pair elements.
+                    const cachedReceipt = pair[ReceiptPairSyntheticIndex] ?? pair[ReceiptPairRealIndex];
+
+                    if (synthetic && preferSynthetic) {
+                        pair[ReceiptPairSyntheticIndex] = wrappedReceipt;
+                    } else if (!synthetic) {
+                        pair[ReceiptPairRealIndex] = wrappedReceipt;
+
+                        if (!preferSynthetic) {
+                            pair[ReceiptPairSyntheticIndex] = null;
+                        }
+                    }
+
+                    const newCachedReceipt = pair[ReceiptPairSyntheticIndex] ?? pair[ReceiptPairRealIndex];
+                    if (cachedReceipt === newCachedReceipt) return;
+
+                    // clean up any previous cache entry
+                    if (cachedReceipt && this.receiptCacheByEventId[cachedReceipt.eventId]) {
+                        const previousEventId = cachedReceipt.eventId;
+                        // Remove the receipt we're about to clobber out of existence from the cache
+                        this.receiptCacheByEventId[previousEventId] = (
+                            this.receiptCacheByEventId[previousEventId].filter(r => {
+                                return r.type !== receiptType || r.userId !== userId;
+                            })
+                        );
+
+                        if (this.receiptCacheByEventId[previousEventId].length < 1) {
+                            delete this.receiptCacheByEventId[previousEventId]; // clean up the cache keys
+                        }
+                    }
+
+                    // cache the new one
+                    if (!this.receiptCacheByEventId[eventId]) {
+                        this.receiptCacheByEventId[eventId] = [];
+                    }
+                    this.receiptCacheByEventId[eventId].push({
+                        userId: userId,
+                        type: receiptType,
+                        data: receipt,
+                    });
                 });
             });
         });
-        return receiptCacheByEventId;
     }
 
     /**
@@ -2072,8 +2229,9 @@ export class Room extends EventEmitter {
      *                   message events into the room.
      */
     public maySendMessage(): boolean {
-        return this.getMyMembership() === 'join' &&
-            this.currentState.maySendEvent(EventType.RoomMessage, this.myUserId);
+        return this.getMyMembership() === 'join' && (this.client.isRoomEncrypted(this.roomId)
+            ? this.currentState.maySendEvent(EventType.RoomMessageEncrypted, this.myUserId)
+            : this.currentState.maySendEvent(EventType.RoomMessage, this.myUserId));
     }
 
     /**
@@ -2159,15 +2317,7 @@ export class Room extends EventEmitter {
             }
         }
 
-        let alias = this.getCanonicalAlias();
-
-        if (!alias) {
-            const aliases = this.getAltAliases();
-
-            if (aliases.length) {
-                alias = aliases[0];
-            }
-        }
+        const alias = this.getCanonicalAlias();
         if (alias) {
             return alias;
         }
@@ -2254,6 +2404,161 @@ export class Room extends EventEmitter {
             return "Empty room";
         }
     }
+
+    /**
+     * When we receive a new visibility change event:
+     *
+     * - store this visibility change alongside the timeline, in case we
+     *   later need to apply it to an event that we haven't received yet;
+     * - if we have already received the event whose visibility has changed,
+     *   patch it to reflect the visibility change and inform listeners.
+     */
+    private applyNewVisibilityEvent(event: MatrixEvent): void {
+        const visibilityChange = event.asVisibilityChange();
+        if (!visibilityChange) {
+            // The event is ill-formed.
+            return;
+        }
+
+        // Ignore visibility change events that are not emitted by moderators.
+        const userId = event.getSender();
+        if (!userId) {
+            return;
+        }
+        const isPowerSufficient =
+            (
+                EVENT_VISIBILITY_CHANGE_TYPE.name
+                && this.currentState.maySendStateEvent(EVENT_VISIBILITY_CHANGE_TYPE.name, userId)
+            )
+            || (
+                EVENT_VISIBILITY_CHANGE_TYPE.altName
+                && this.currentState.maySendStateEvent(EVENT_VISIBILITY_CHANGE_TYPE.altName, userId)
+            );
+        if (!isPowerSufficient) {
+            // Powerlevel is insufficient.
+            return;
+        }
+
+        // Record this change in visibility.
+        // If the event is not in our timeline and we only receive it later,
+        // we may need to apply the visibility change at a later date.
+
+        const visibilityEventsOnOriginalEvent = this.visibilityEvents.get(visibilityChange.eventId);
+        if (visibilityEventsOnOriginalEvent) {
+            // It would be tempting to simply erase the latest visibility change
+            // but we need to record all of the changes in case the latest change
+            // is ever redacted.
+            //
+            // In practice, linear scans through `visibilityEvents` should be fast.
+            // However, to protect against a potential DoS attack, we limit the
+            // number of iterations in this loop.
+            let index = visibilityEventsOnOriginalEvent.length - 1;
+            const min = Math.max(0,
+                visibilityEventsOnOriginalEvent.length - MAX_NUMBER_OF_VISIBILITY_EVENTS_TO_SCAN_THROUGH);
+            for (; index >= min; --index) {
+                const target = visibilityEventsOnOriginalEvent[index];
+                if (target.getTs() < event.getTs()) {
+                    break;
+                }
+            }
+            if (index === -1) {
+                visibilityEventsOnOriginalEvent.unshift(event);
+            } else {
+                visibilityEventsOnOriginalEvent.splice(index + 1, 0, event);
+            }
+        } else {
+            this.visibilityEvents.set(visibilityChange.eventId, [event]);
+        }
+
+        // Finally, let's check if the event is already in our timeline.
+        // If so, we need to patch it and inform listeners.
+
+        const originalEvent = this.findEventById(visibilityChange.eventId);
+        if (!originalEvent) {
+            return;
+        }
+        originalEvent.applyVisibilityEvent(visibilityChange);
+    }
+
+    private redactVisibilityChangeEvent(event: MatrixEvent) {
+        // Sanity checks.
+        if (!event.isVisibilityEvent) {
+            throw new Error("expected a visibility change event");
+        }
+        const relation = event.getRelation();
+        const originalEventId = relation.event_id;
+        const visibilityEventsOnOriginalEvent = this.visibilityEvents.get(originalEventId);
+        if (!visibilityEventsOnOriginalEvent) {
+            // No visibility changes on the original event.
+            // In particular, this change event was not recorded,
+            // most likely because it was ill-formed.
+            return;
+        }
+        const index = visibilityEventsOnOriginalEvent.findIndex(change => change.getId() === event.getId());
+        if (index === -1) {
+            // This change event was not recorded, most likely because
+            // it was ill-formed.
+            return;
+        }
+        // Remove visibility change.
+        visibilityEventsOnOriginalEvent.splice(index, 1);
+
+        // If we removed the latest visibility change event, propagate changes.
+        if (index === visibilityEventsOnOriginalEvent.length) {
+            const originalEvent = this.findEventById(originalEventId);
+            if (!originalEvent) {
+                return;
+            }
+            if (index === 0) {
+                // We have just removed the only visibility change event.
+                this.visibilityEvents.delete(originalEventId);
+                originalEvent.applyVisibilityEvent();
+            } else {
+                const newEvent = visibilityEventsOnOriginalEvent[visibilityEventsOnOriginalEvent.length - 1];
+                const newVisibility = newEvent.asVisibilityChange();
+                if (!newVisibility) {
+                    // Event is ill-formed.
+                    // This breaks our invariant.
+                    throw new Error("at this stage, visibility changes should be well-formed");
+                }
+                originalEvent.applyVisibilityEvent(newVisibility);
+            }
+        }
+    }
+
+    /**
+     * When we receive an event whose visibility has been altered by
+     * a (more recent) visibility change event, patch the event in
+     * place so that clients now not to display it.
+     *
+     * @param event Any matrix event. If this event has at least one a
+     * pending visibility change event, apply the latest visibility
+     * change event.
+     */
+    private applyPendingVisibilityEvents(event: MatrixEvent): void {
+        const visibilityEvents = this.visibilityEvents.get(event.getId());
+        if (!visibilityEvents || visibilityEvents.length == 0) {
+            // No pending visibility change in store.
+            return;
+        }
+        const visibilityEvent = visibilityEvents[visibilityEvents.length - 1];
+        const visibilityChange = visibilityEvent.asVisibilityChange();
+        if (!visibilityChange) {
+            return;
+        }
+        if (visibilityChange.visible) {
+            // Events are visible by default, no need to apply a visibility change.
+            // Note that we need to keep the visibility changes in `visibilityEvents`,
+            // in case we later fetch an older visibility change event that is superseded
+            // by `visibilityChange`.
+        }
+        if (visibilityEvent.getTs() < event.getTs()) {
+            // Something is wrong, the visibility change cannot happen before the
+            // event. Presumably an ill-formed event.
+            return;
+        }
+        event.applyVisibilityEvent(visibilityChange);
+    }
 }
 
 /**
@@ -2264,12 +2569,12 @@ function pendingEventsKey(roomId: string): string {
     return `mx_pending_events_${roomId}`;
 }
 
-/* a map from current event status to a list of allowed next statuses
-     */
+// a map from current event status to a list of allowed next statuses
 const ALLOWED_TRANSITIONS: Record<EventStatus, EventStatus[]> = {
     [EventStatus.ENCRYPTING]: [
         EventStatus.SENDING,
         EventStatus.NOT_SENT,
+        EventStatus.CANCELLED,
     ],
     [EventStatus.SENDING]: [
         EventStatus.ENCRYPTING,
@@ -2422,3 +2727,4 @@ function memberNamesToRoomName(names: string[], count = (names.length + 1)) {
  * @param {string} membership The new membership value
  * @param {string} prevMembership The previous membership value
  */
+

src/models/thread.ts

@@ -15,11 +15,15 @@ limitations under the License.
 */
 
 import { MatrixClient } from "../matrix";
-import { MatrixEvent } from "./event";
-import { EventTimeline } from "./event-timeline";
+import { ReEmitter } from "../ReEmitter";
+import { RelationType } from "../@types/event";
+import { IRelationsRequestOpts } from "../@types/requests";
+import { MatrixEvent, IThreadBundledRelationship } from "./event";
+import { Direction, EventTimeline } from "./event-timeline";
 import { EventTimelineSet } from './event-timeline-set';
 import { Room } from './room';
 import { TypedEventEmitter } from "./typed-event-emitter";
+import { RoomState } from "./room-state";
 
 export enum ThreadEvent {
     New = "Thread.new",
@@ -29,14 +33,16 @@ export enum ThreadEvent {
     ViewThread = "Thred.viewThread",
 }
 
+interface IThreadOpts {
+    initialEvents?: MatrixEvent[];
+    room: Room;
+    client: MatrixClient;
+}
+
 /**
  * @experimental
  */
 export class Thread extends TypedEventEmitter<ThreadEvent> {
-    /**
-     * A reference to the event ID at the top of the thread
-     */
-    private root: string;
     /**
      * A reference to all the events ID at the bottom of the threads
      */
@@ -44,25 +50,57 @@ export class Thread extends TypedEventEmitter<ThreadEvent> {
 
     private _currentUserParticipated = false;
 
+    private reEmitter: ReEmitter;
+
+    private lastEvent: MatrixEvent;
+    private replyCount = 0;
+
+    public readonly room: Room;
+    public readonly client: MatrixClient;
+
+    public initialEventsFetched = false;
+
+    public readonly id: string;
+
     constructor(
-        events: MatrixEvent[] = [],
-        public readonly room: Room,
-        public readonly client: MatrixClient,
+        public readonly rootEvent: MatrixEvent | undefined,
+        opts: IThreadOpts,
     ) {
         super();
-        if (events.length === 0) {
-            throw new Error("Can't create an empty thread");
-        }
 
+        this.room = opts.room;
+        this.client = opts.client;
         this.timelineSet = new EventTimelineSet(this.room, {
             unstableClientRelationAggregation: true,
             timelineSupport: true,
             pendingEvents: true,
         });
-        events.forEach(event => this.addEvent(event));
+        this.reEmitter = new ReEmitter(this);
 
-        room.on("Room.localEchoUpdated", this.onEcho);
-        room.on("Room.timeline", this.onEcho);
+        this.reEmitter.reEmit(this.timelineSet, [
+            "Room.timeline",
+            "Room.timelineReset",
+        ]);
+
+        // If we weren't able to find the root event, it's probably missing
+        // and we define the thread ID from one of the thread relation
+        if (!rootEvent) {
+            this.id = opts?.initialEvents
+                ?.find(event => event.isThreadRelation)?.relationEventId;
+        } else {
+            this.id = rootEvent.getId();
+        }
+        this.initialiseThread(this.rootEvent);
+
+        opts?.initialEvents?.forEach(event => this.addEvent(event));
+
+        this.room.on("Room.localEchoUpdated", this.onEcho);
+        this.room.on("Room.timeline", this.onEcho);
+    }
+
+    public get hasServerSideSupport(): boolean {
+        return this.client.cachedCapabilities
+            ?.capabilities?.[RelationType.Thread]?.enabled;
     }
 
     onEcho = (event: MatrixEvent) => {
@@ -71,6 +109,10 @@ export class Thread extends TypedEventEmitter<ThreadEvent> {
         }
     };
 
+    public get roomState(): RoomState {
+        return this.room.getLiveTimeline().getState(EventTimeline.FORWARDS);
+    }
+
     /**
      * Add an event to the thread and updates
      * the tail/root references if needed
@@ -78,43 +120,104 @@ export class Thread extends TypedEventEmitter<ThreadEvent> {
      * @param event The event to add
      */
     public async addEvent(event: MatrixEvent, toStartOfTimeline = false): Promise<void> {
-        if (this.timelineSet.findEventById(event.getId()) || event.status !== null) {
-            return;
+        // Add all incoming events to the thread's timeline set when there's
+        // no server support
+        if (!this.hasServerSideSupport) {
+            if (this.timelineSet.findEventById(event.getId())) {
+                return;
+            }
+
+            // all the relevant membership info to hydrate events with a sender
+            // is held in the main room timeline
+            // We want to fetch the room state from there and pass it down to this thread
+            // timeline set to let it reconcile an event with its relevant RoomMember
+
+            event.setThread(this);
+            this.timelineSet.addEventToTimeline(
+                event,
+                this.liveTimeline,
+                toStartOfTimeline,
+                false,
+                this.roomState,
+            );
+
+            await this.client.decryptEventIfNeeded(event, {});
         }
 
-        if (!this.root) {
-            if (event.isThreadRelation) {
-                this.root = event.threadRootId;
-            } else {
-                this.root = event.getId();
+        if (this.hasServerSideSupport && this.initialEventsFetched) {
+            if (event.localTimestamp > this.lastReply().localTimestamp && !this.findEventById(event.getId())) {
+                this.timelineSet.addEventToTimeline(
+                    event,
+                    this.liveTimeline,
+                    false,
+                    false,
+                    this.roomState,
+                );
             }
         }
 
-        // all the relevant membership info to hydrate events with a sender
-        // is held in the main room timeline
-        // We want to fetch the room state from there and pass it down to this thread
-        // timeline set to let it reconcile an event with its relevant RoomMember
-        const roomState = this.room.getLiveTimeline().getState(EventTimeline.FORWARDS);
-
-        event.setThread(this);
-        this.timelineSet.addEventToTimeline(
-            event,
-            this.timelineSet.getLiveTimeline(),
-            toStartOfTimeline,
-            false,
-            roomState,
-        );
-
         if (!this._currentUserParticipated && event.getSender() === this.client.getUserId()) {
             this._currentUserParticipated = true;
         }
 
-        await this.client.decryptEventIfNeeded(event, {});
-        this.emit(ThreadEvent.Update, this);
-
-        if (event.isThreadRelation) {
-            this.emit(ThreadEvent.NewReply, this, event);
+        const isThreadReply = event.getRelation()?.rel_type === RelationType.Thread;
+        // If no thread support exists we want to count all thread relation
+        // added as a reply. We can't rely on the bundled relationships count
+        if (!this.hasServerSideSupport && isThreadReply) {
+            this.replyCount++;
         }
+
+        // There is a risk that the `localTimestamp` approximation will not be accurate
+        // when threads are used over federation. That could results in the reply
+        // count value drifting away from the value returned by the server
+        if (!this.lastEvent || (isThreadReply && event.localTimestamp > this.replyToEvent.localTimestamp)) {
+            this.lastEvent = event;
+            if (this.lastEvent.getId() !== this.id) {
+                // This counting only works when server side support is enabled
+                // as we started the counting from the value returned in the
+                // bundled relationship
+                if (this.hasServerSideSupport) {
+                    this.replyCount++;
+                }
+
+                this.emit(ThreadEvent.NewReply, this, event);
+            }
+        }
+
+        this.emit(ThreadEvent.Update, this);
+    }
+
+    private initialiseThread(rootEvent: MatrixEvent | undefined): void {
+        const bundledRelationship = rootEvent
+            ?.getServerAggregatedRelation<IThreadBundledRelationship>(RelationType.Thread);
+
+        if (this.hasServerSideSupport && bundledRelationship) {
+            this.replyCount = bundledRelationship.count;
+            this._currentUserParticipated = bundledRelationship.current_user_participated;
+
+            const event = new MatrixEvent(bundledRelationship.latest_event);
+            this.setEventMetadata(event);
+            this.lastEvent = event;
+        }
+
+        if (!bundledRelationship && rootEvent) {
+            this.addEvent(rootEvent);
+        }
+    }
+
+    public async fetchInitialEvents(): Promise<boolean> {
+        try {
+            await this.fetchEvents();
+            this.initialEventsFetched = true;
+            return true;
+        } catch (e) {
+            return false;
+        }
+    }
+
+    private setEventMetadata(event: MatrixEvent): void {
+        EventTimeline.setEventMetadata(event, this.roomState, false);
+        event.setThread(this);
     }
 
     /**
@@ -127,28 +230,17 @@ export class Thread extends TypedEventEmitter<ThreadEvent> {
     /**
      * Return last reply to the thread
      */
-    public get lastReply(): MatrixEvent {
-        const threadReplies = this.events
-            .filter(event => event.isThreadRelation);
-        return threadReplies[threadReplies.length - 1];
-    }
-
-    /**
-     * The thread ID, which is the same as the root event ID
-     */
-    public get id(): string {
-        return this.root;
-    }
-
-    /**
-     * The thread root event
-     */
-    public get rootEvent(): MatrixEvent {
-        return this.findEventById(this.root);
+    public lastReply(matches: (ev: MatrixEvent) => boolean = () => true): MatrixEvent {
+        for (let i = this.events.length - 1; i >= 0; i--) {
+            const event = this.events[i];
+            if (matches(event)) {
+                return event;
+            }
+        }
     }
 
     public get roomId(): string {
-        return this.rootEvent.getRoomId();
+        return this.room.roomId;
     }
 
     /**
@@ -157,28 +249,18 @@ export class Thread extends TypedEventEmitter<ThreadEvent> {
      * exclude annotations from that number
      */
     public get length(): number {
-        return this.events
-            .filter(event => event.isThreadRelation)
-            .length;
+        return this.replyCount;
     }
 
     /**
      * A getter for the last event added to the thread
      */
     public get replyToEvent(): MatrixEvent {
-        const events = this.events;
-        return events[events.length -1];
+        return this.lastEvent;
     }
 
     public get events(): MatrixEvent[] {
-        return this.timelineSet.getLiveTimeline().getEvents();
-    }
-
-    public merge(thread: Thread): void {
-        thread.events.forEach(event => {
-            this.addEvent(event);
-        });
-        this.events.forEach(event => event.setThread(this));
+        return this.liveTimeline.getEvents();
     }
 
     public has(eventId: string): boolean {
@@ -188,4 +270,55 @@ export class Thread extends TypedEventEmitter<ThreadEvent> {
     public get hasCurrentUserParticipated(): boolean {
         return this._currentUserParticipated;
     }
+
+    public get liveTimeline(): EventTimeline {
+        return this.timelineSet.getLiveTimeline();
+    }
+
+    public async fetchEvents(opts: IRelationsRequestOpts = { limit: 20 }): Promise<{
+        originalEvent: MatrixEvent;
+        events: MatrixEvent[];
+        nextBatch?: string;
+        prevBatch?: string;
+    }> {
+        let {
+            originalEvent,
+            events,
+            prevBatch,
+            nextBatch,
+        } = await this.client.relations(
+            this.room.roomId,
+            this.id,
+            RelationType.Thread,
+            null,
+            opts,
+        );
+
+        // When there's no nextBatch returned with a `from` request we have reached
+        // the end of the thread, and therefore want to return an empty one
+        if (!opts.to && !nextBatch) {
+            events = [originalEvent, ...events];
+        }
+
+        for (const event of events) {
+            await this.client.decryptEventIfNeeded(event);
+            this.setEventMetadata(event);
+        }
+
+        const prependEvents = !opts.direction || opts.direction === Direction.Backward;
+
+        this.timelineSet.addEventsToTimeline(
+            events,
+            prependEvents,
+            this.liveTimeline,
+            prependEvents ? nextBatch : prevBatch,
+        );
+
+        return {
+            originalEvent,
+            events,
+            prevBatch,
+            nextBatch,
+        };
+    }
 }

src/room-hierarchy.ts

@@ -112,7 +112,7 @@ export class RoomHierarchy {
                 if (!this.backRefs.has(childRoomId)) {
                     this.backRefs.set(childRoomId, []);
                 }
-                this.backRefs.get(childRoomId).push(ev.room_id);
+                this.backRefs.get(childRoomId).push(room.room_id);
 
                 // fill viaMap
                 if (Array.isArray(ev.content.via)) {

src/scheduler.ts

@@ -70,7 +70,7 @@ export class MatrixScheduler<T = ISendEventResponse> {
         }
         // we ship with browser-request which returns { cors: rejected } when trying
         // with no connection, so if we match that, give up since they have no conn.
-        if (err.cors === "rejected") {
+        if (err["cors"] === "rejected") {
             return -1;
         }
 

src/store/indexeddb-local-backend.ts

@@ -231,7 +231,7 @@ export class LocalIndexedDBStoreBackend implements IIndexedDBBackend {
      * @returns {null} in case the members for this room haven't been stored yet
      */
     public getOutOfBandMembers(roomId: string): Promise<IEvent[] | null> {
-        return new Promise<IEvent[] | null>((resolve, reject) =>{
+        return new Promise<IEvent[] | null>((resolve, reject) => {
             const tx = this.db.transaction(["oob_membership_events"], "readonly");
             const store = tx.objectStore("oob_membership_events");
             const roomIndex = store.index("room");

src/store/session/webstorage.js

@@ -256,8 +256,8 @@ function removeByPrefix(store, prefix) {
     }
 }
 
-function debuglog() {
+function debuglog(...args) {
     if (DEBUG) {
-        logger.log(...arguments);
+        logger.log(...args);
     }
 }

src/sync-accumulator.ts

@@ -32,6 +32,7 @@ interface IOpts {
 export interface IMinimalEvent {
     content: IContent;
     type: EventType | string;
+    unsigned?: IUnsigned;
 }
 
 export interface IEphemeral {

src/sync.ts

@@ -34,23 +34,22 @@ import { PushProcessor } from "./pushprocessor";
 import { logger } from './logger';
 import { InvalidStoreError } from './errors';
 import { IStoredClientOpts, MatrixClient, PendingEventOrdering } from "./client";
-import { SyncState } from "./sync.api";
 import {
     Category,
+    IEphemeral,
     IInvitedRoom,
     IInviteState,
     IJoinedRoom,
     ILeftRoom,
-    IStateEvent,
+    IMinimalEvent,
     IRoomEvent,
+    IStateEvent,
     IStrippedState,
     ISyncResponse,
     ITimeline,
-    IEphemeral,
-    IMinimalEvent,
 } from "./sync-accumulator";
 import { MatrixEvent } from "./models/event";
-import { MatrixError } from "./http-api";
+import { MatrixError, Method } from "./http-api";
 import { ISavedSync } from "./store";
 import { EventType } from "./@types/event";
 import { IPushRules } from "./@types/PushRules";
@@ -68,6 +67,15 @@ const BUFFER_PERIOD_MS = 80 * 1000;
 // keepAlive is successful but the server /sync fails.
 const FAILED_SYNC_ERROR_THRESHOLD = 3;
 
+export enum SyncState {
+    Error = "ERROR",
+    Prepared = "PREPARED",
+    Stopped = "STOPPED",
+    Syncing = "SYNCING",
+    Catchup = "CATCHUP",
+    Reconnecting = "RECONNECTING",
+}
+
 function getFilterName(userId: string, suffix?: string): string {
     // scope this on the user ID because people may login on many accounts
     // and they all need to be stored!
@@ -87,13 +95,19 @@ interface ISyncOptions {
 }
 
 export interface ISyncStateData {
-    error?: Error;
+    error?: MatrixError;
     oldSyncToken?: string;
     nextSyncToken?: string;
     catchingUp?: boolean;
     fromCache?: boolean;
 }
 
+enum SetPresence {
+    Offline = "offline",
+    Online = "online",
+    Unavailable = "unavailable",
+}
+
 interface ISyncParams {
     filter?: string;
     timeout: number;
@@ -101,7 +115,7 @@ interface ISyncParams {
     // eslint-disable-next-line camelcase
     full_state?: boolean;
     // eslint-disable-next-line camelcase
-    set_presence?: "offline" | "online" | "unavailable";
+    set_presence?: SetPresence;
     _cacheBuster?: string | number; // not part of the API itself
 }
 
@@ -187,6 +201,7 @@ export class SyncApi {
             "Room.accountData",
             "Room.myMembership",
             "Room.replaceEvent",
+            "Room.visibilityChange",
         ]);
         this.registerStateListeners(room);
         return room;
@@ -260,16 +275,16 @@ export class SyncApi {
             getFilterName(client.credentials.userId, "LEFT_ROOMS"), filter,
         ).then(function(filterId) {
             qps.filter = filterId;
-            return client.http.authedRequest(
-                undefined, "GET", "/sync", qps, undefined, localTimeoutMs,
+            return client.http.authedRequest<any>( // TODO types
+                undefined, Method.Get, "/sync", qps as any, undefined, localTimeoutMs,
             );
         }).then((data) => {
             let leaveRooms = [];
-            if (data.rooms && data.rooms.leave) {
+            if (data.rooms?.leave) {
                 leaveRooms = this.mapSyncResponseToRoomArray(data.rooms.leave);
             }
             const rooms = [];
-            leaveRooms.forEach((leaveObj) => {
+            leaveRooms.forEach(async (leaveObj) => {
                 const room = leaveObj.room;
                 rooms.push(room);
                 if (!leaveObj.isBrandNewRoom) {
@@ -295,7 +310,7 @@ export class SyncApi {
                     EventTimeline.BACKWARDS);
 
                 this.processRoomEvents(room, stateEvents, timelineEvents);
-                this.processThreadEvents(room, threadedEvents);
+                await this.processThreadEvents(room, threadedEvents);
 
                 room.recalculate();
                 client.store.storeRoom(room);
@@ -400,9 +415,10 @@ export class SyncApi {
         }
 
         // FIXME: gut wrenching; hard-coded timeout values
-        this.client.http.authedRequest(undefined, "GET", "/events", {
+        // TODO types
+        this.client.http.authedRequest<any>(undefined, Method.Get, "/events", {
             room_id: peekRoom.roomId,
-            timeout: 30 * 1000,
+            timeout: String(30 * 1000),
             from: token,
         }, undefined, 50 * 1000).then((res) => {
             if (this._peekRoom !== peekRoom) {
@@ -470,7 +486,7 @@ export class SyncApi {
         return this.syncStateData;
     }
 
-    public async recoverFromSyncStartupError(savedSyncPromise: Promise<void>, err: Error): Promise<void> {
+    public async recoverFromSyncStartupError(savedSyncPromise: Promise<void>, err: MatrixError): Promise<void> {
         // Wait for the saved sync to complete - we send the pushrules and filter requests
         // before the saved sync has finished so they can run in parallel, but only process
         // the results after the saved sync is done. Equivalently, we wait for it to finish
@@ -865,8 +881,8 @@ export class SyncApi {
 
     private doSyncRequest(syncOptions: ISyncOptions, syncToken: string): IRequestPromise<ISyncResponse> {
         const qps = this.getSyncParams(syncOptions, syncToken);
-        return this.client.http.authedRequest(
-            undefined, "GET", "/sync", qps, undefined,
+        return this.client.http.authedRequest( // TODO types
+            undefined, Method.Get, "/sync", qps as any, undefined,
             qps.timeout + BUFFER_PERIOD_MS,
         );
     }
@@ -901,7 +917,7 @@ export class SyncApi {
         };
 
         if (this.opts.disablePresence) {
-            qps.set_presence = "offline";
+            qps.set_presence = SetPresence.Offline;
         }
 
         if (syncToken) {
@@ -924,7 +940,7 @@ export class SyncApi {
         return qps;
     }
 
-    private onSyncError(err: Error, syncOptions: ISyncOptions): void {
+    private onSyncError(err: MatrixError, syncOptions: ISyncOptions): void {
         if (!this.running) {
             debuglog("Sync no longer running: exiting");
             if (this.connectionReturnedDefer) {
@@ -1291,7 +1307,7 @@ export class SyncApi {
             const [timelineEvents, threadedEvents] = this.client.partitionThreadedEvents(events);
 
             this.processRoomEvents(room, stateEvents, timelineEvents, syncEventData.fromCache);
-            this.processThreadEvents(room, threadedEvents);
+            await this.processThreadEvents(room, threadedEvents);
 
             // set summary after processing events,
             // because it will trigger a name calculation
@@ -1350,7 +1366,7 @@ export class SyncApi {
         });
 
         // Handle leaves (e.g. kicked rooms)
-        leaveRooms.forEach((leaveObj) => {
+        leaveRooms.forEach(async (leaveObj) => {
             const room = leaveObj.room;
             const stateEvents = this.mapSyncEventsFormat(leaveObj.state, room);
             const events = this.mapSyncEventsFormat(leaveObj.timeline, room);
@@ -1359,7 +1375,7 @@ export class SyncApi {
             const [timelineEvents, threadedEvents] = this.client.partitionThreadedEvents(events);
 
             this.processRoomEvents(room, stateEvents, timelineEvents);
-            this.processThreadEvents(room, threadedEvents);
+            await this.processThreadEvents(room, threadedEvents);
             room.addAccountData(accountDataEvents);
 
             room.recalculate();
@@ -1477,7 +1493,7 @@ export class SyncApi {
 
         this.client.http.request(
             undefined, // callback
-            "GET", "/_matrix/client/versions",
+            Method.Get, "/_matrix/client/versions",
             undefined, // queryParams
             undefined, // data
             {
@@ -1704,7 +1720,7 @@ export class SyncApi {
     /**
      * @experimental
      */
-    private processThreadEvents(room: Room, threadedEvents: MatrixEvent[]): void {
+    private processThreadEvents(room: Room, threadedEvents: MatrixEvent[]): Promise<void> {
         return this.client.processThreadEvents(room, threadedEvents);
     }
 

src/webrtc/call.ts

@@ -937,7 +937,7 @@ export class MatrixCall extends EventEmitter {
             const upgradeVideo = video && !this.hasLocalUserMediaVideoTrack;
             logger.debug(`Upgrading call: audio?=${upgradeAudio} video?=${upgradeVideo}`);
 
-            const stream = await this.client.getMediaHandler().getUserMediaStream(upgradeAudio, upgradeVideo);
+            const stream = await this.client.getMediaHandler().getUserMediaStream(upgradeAudio, upgradeVideo, false);
             if (upgradeAudio && upgradeVideo) {
                 if (this.hasLocalUserMediaAudioTrack) return;
                 if (this.hasLocalUserMediaVideoTrack) return;
@@ -1717,7 +1717,12 @@ export class MatrixCall extends EventEmitter {
 
         const stream = ev.streams[0];
         this.pushRemoteFeed(stream);
-        stream.addEventListener("removetrack", () => this.deleteFeedByStream(stream));
+        stream.addEventListener("removetrack", () => {
+            if (stream.getTracks().length === 0) {
+                logger.info(`Stream ID ${stream.id} has no tracks remaining - removing`);
+                this.deleteFeedByStream(stream);
+            }
+        });
     };
 
     private onDataChannel = (ev: RTCDataChannelEvent): void => {
@@ -1973,7 +1978,7 @@ export class MatrixCall extends EventEmitter {
     }
 
     private stopAllMedia(): void {
-        logger.debug(`stopAllMedia (stream=${this.localUsermediaStream})`);
+        logger.debug("Stopping all media for call", this.callId);
 
         for (const feed of this.feeds) {
             if (feed.isLocal() && feed.purpose === SDPStreamMetadataPurpose.Usermedia) {
@@ -1981,6 +1986,7 @@ export class MatrixCall extends EventEmitter {
             } else if (feed.isLocal() && feed.purpose === SDPStreamMetadataPurpose.Screenshare) {
                 this.client.getMediaHandler().stopScreensharingStream(feed.stream);
             } else {
+                logger.debug("Stopping remote stream", feed.stream.id);
                 for (const track of feed.stream.getTracks()) {
                     track.stop();
                 }

src/webrtc/mediaHandler.ts

@@ -54,9 +54,12 @@ export class MediaHandler {
     }
 
     /**
+     * @param audio should have an audio track
+     * @param video should have a video track
+     * @param reusable is allowed to be reused by the MediaHandler
      * @returns {MediaStream} based on passed parameters
      */
-    public async getUserMediaStream(audio: boolean, video: boolean): Promise<MediaStream> {
+    public async getUserMediaStream(audio: boolean, video: boolean, reusable = true): Promise<MediaStream> {
         const shouldRequestAudio = audio && await this.hasAudioDevice();
         const shouldRequestVideo = video && await this.hasVideoDevice();
 
@@ -78,7 +81,9 @@ export class MediaHandler {
             stream = await navigator.mediaDevices.getUserMedia(constraints);
         }
 
-        this.userMediaStreams.push(stream);
+        if (reusable) {
+            this.userMediaStreams.push(stream);
+        }
 
         return stream;
     }
@@ -101,9 +106,11 @@ export class MediaHandler {
     }
 
     /**
+     * @param desktopCapturerSourceId sourceId for Electron DesktopCapturer
+     * @param reusable is allowed to be reused by the MediaHandler
      * @returns {MediaStream} based on passed parameters
      */
-    public async getScreensharingStream(desktopCapturerSourceId: string): Promise<MediaStream | null> {
+    public async getScreensharingStream(desktopCapturerSourceId: string, reusable = true): Promise<MediaStream | null> {
         let stream: MediaStream;
 
         if (this.screensharingStreams.length === 0) {
@@ -125,7 +132,9 @@ export class MediaHandler {
             stream = matchingStream.clone();
         }
 
-        this.screensharingStreams.push(stream);
+        if (reusable) {
+            this.screensharingStreams.push(stream);
+        }
 
         return stream;
     }