chore(common): send Studio empty-body diagnostics to Sentry unsampled

filterSentryEvent keeps 1% of non-crash events, which would leave almost
nothing of a once-per-session warning. Exempt events tagged
`empty_body_diagnostic` from sampling; only Studio's empty-body reporter
sets that tag, so www and docs are unaffected.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UefDak8XYLMi9aiEjDPXc5

apps/studio/data/empty-body-diagnostics.test.ts

@@ -87,7 +87,11 @@ describe('reportEmptyBodyResponse', () => {
     expect(context).toMatchObject({
       level: 'warning',
       fingerprint: ['empty-body-response', '/platform/projects/{ref}/a'],
-      tags: { endpoint: '/platform/projects/{ref}/a', probe_has_body: 'true' },
+      tags: {
+        endpoint: '/platform/projects/{ref}/a',
+        probe_has_body: 'true',
+        empty_body_diagnostic: 'true',
+      },
       extra: {
         method: 'GET',
         status: 200,

apps/studio/data/empty-body-diagnostics.ts

@@ -161,7 +161,7 @@ export async function reportEmptyBodyResponse({
     Sentry.captureMessage('Empty response body on successful API request', {
       level: 'warning',
       fingerprint: ['empty-body-response', endpoint],
-      tags: { endpoint, probe_has_body },
+      tags: { endpoint, probe_has_body, empty_body_diagnostic: 'true' },
       extra: { ...context, ...probeContext },
     })
   } catch (error) {

packages/common/sentry.test.ts

@@ -51,6 +51,30 @@ describe('which errors get sent to Sentry', () => {
     expect(filterSentryEvent(event, enabled) === event).toBe(isSent)
   })
 
+  it.each([true, 'true'])(
+    'sends every Studio empty-body diagnostic without sampling: %s',
+    (tag) => {
+      const random = vi.spyOn(Math, 'random').mockReturnValue(0.99)
+      const event = { tags: { empty_body_diagnostic: tag } }
+      expect(filterSentryEvent(event, enabled)).toBe(event)
+      expect(event.tags).toEqual({ empty_body_diagnostic: tag, codeSampleRate: '1' })
+      expect(random).not.toHaveBeenCalled()
+    }
+  )
+
+  it.each([false, 'false', null])(
+    'still samples events whose empty-body diagnostic tag is not set: %s',
+    (tag) => {
+      vi.spyOn(Math, 'random').mockReturnValue(0.99)
+      expect(filterSentryEvent({ tags: { empty_body_diagnostic: tag } }, enabled)).toBeNull()
+    }
+  )
+
+  it('drops empty-body diagnostics when reporting is turned off', () => {
+    const tags = { empty_body_diagnostic: 'true' }
+    expect(filterSentryEvent({ tags }, { isPlatform: true, hasConsent: false })).toBeNull()
+  })
+
   it.each([undefined, false, 'false', null, 1])(
     'drops errors from outside the app unless marked as a page crash: %s',
     (tag) => {

packages/common/sentry.ts

@@ -3,6 +3,7 @@ type SentryEventTags = {
     globalErrorBoundary?: string | number | boolean | null
     third_party_code?: string | number | boolean | null
     codeSampleRate?: string | number | boolean | null
+    empty_body_diagnostic?: string | number | boolean | null
   }
 }
 
@@ -22,12 +23,18 @@ export function filterSentryEvent<T extends SentryEventTags>(
   const isThirdPartyOnly =
     event.tags?.third_party_code === true || event.tags?.third_party_code === 'true'
 
+  // Studio's once-per-session empty-body diagnostic is too rare to sample
+  const isUnsampled =
+    isErrorBoundaryCrash ||
+    event.tags?.empty_body_diagnostic === true ||
+    event.tags?.empty_body_diagnostic === 'true'
+
   if (isThirdPartyOnly && !isErrorBoundaryCrash) return null
-  if (!isErrorBoundaryCrash && Math.random() >= NON_CRASH_ERROR_SAMPLE_RATE) return null
+  if (!isUnsampled && Math.random() >= NON_CRASH_ERROR_SAMPLE_RATE) return null
 
   event.tags = {
     ...event.tags,
-    codeSampleRate: isErrorBoundaryCrash ? '1' : NON_CRASH_ERROR_SAMPLE_RATE.toString(),
+    codeSampleRate: isUnsampled ? '1' : NON_CRASH_ERROR_SAMPLE_RATE.toString(),
   }
 
   return event