fix(replay): Ensure dropped errors are removed from replay reference

packages/replay/src/index.ts

@@ -1,7 +1,7 @@
 /* eslint-disable max-lines */ // TODO: We might want to split this file up
 import type { BrowserClient, BrowserOptions } from '@sentry/browser';
 import { addGlobalEventProcessor, getCurrentHub, Scope, setContext } from '@sentry/core';
-import { Breadcrumb, Client, Event, Integration } from '@sentry/types';
+import { Breadcrumb, Client, DataCategory, Event, EventDropReason, Integration } from '@sentry/types';
 import { addInstrumentationHandler, createEnvelope, logger } from '@sentry/utils';
 import debounce from 'lodash.debounce';
 import { PerformanceObserverEntryList } from 'perf_hooks';
@@ -126,6 +126,11 @@ export class Replay implements Integration {
    */
   private stopRecording: ReturnType<typeof record> | null = null;
 
+  /**
+   * We overwrite `client.recordDroppedEvent`, but store the original method here so we can restore it.
+   */
+  private _originalRecordDroppedEvent?: Client['recordDroppedEvent'];
+
   private context: InternalEventContext = {
     errorIds: new Set(),
     traceIds: new Set(),
@@ -405,6 +410,9 @@ export class Replay implements Integration {
       WINDOW.addEventListener('blur', this.handleWindowBlur);
       WINDOW.addEventListener('focus', this.handleWindowFocus);
 
+      // We need to filter out dropped events captured by `addGlobalEventProcessor(this.handleGlobalEvent)` below
+      this._overwriteRecordDroppedEvent();
+
       // There is no way to remove these listeners, so ensure they are only added once
       if (!this.hasInitializedCoreListeners) {
         // Listeners from core SDK //
@@ -467,6 +475,8 @@ export class Replay implements Integration {
       WINDOW.removeEventListener('blur', this.handleWindowBlur);
       WINDOW.removeEventListener('focus', this.handleWindowFocus);
 
+      this._restoreRecordDroppedEvent();
+
       if (this.performanceObserver) {
         this.performanceObserver.disconnect();
         this.performanceObserver = null;
@@ -1352,4 +1362,39 @@ export class Replay implements Integration {
       this.options.errorSampleRate = opt.replaysOnErrorSampleRate;
     }
   }
+
+  private _overwriteRecordDroppedEvent(): void {
+    const client = getCurrentHub().getClient();
+
+    if (!client) {
+      return;
+    }
+
+    const _originalCallback = client.recordDroppedEvent.bind(client);
+
+    const recordDroppedEvent: Client['recordDroppedEvent'] = (
+      reason: EventDropReason,
+      category: DataCategory,
+      event?: Event,
+    ): void => {
+      if (event && event.event_id) {
+        this.context.errorIds.delete(event.event_id);
+      }
+
+      return _originalCallback(reason, category, event);
+    };
+
+    client.recordDroppedEvent = recordDroppedEvent;
+    this._originalRecordDroppedEvent = _originalCallback;
+  }
+
+  private _restoreRecordDroppedEvent(): void {
+    const client = getCurrentHub().getClient();
+
+    if (!client || !this._originalRecordDroppedEvent) {
+      return;
+    }
+
+    client.recordDroppedEvent = this._originalRecordDroppedEvent;
+  }
 }

packages/replay/test/unit/index-handleGlobalEvent.test.ts

@@ -1,3 +1,4 @@
+import { getCurrentHub } from '@sentry/core';
 import { Error } from '@test/fixtures/error';
 import { Transaction } from '@test/fixtures/transaction';
 import { resetSdkMock } from '@test/mocks';
@@ -83,6 +84,27 @@ it('only tags errors with replay id, adds trace and error id to context for erro
   expect(replay.waitForError).toBe(false);
 });
 
+it('strips out dropped events from errorIds', async () => {
+  const error1 = Error({ event_id: 'err1' });
+  const error2 = Error({ event_id: 'err2' });
+  const error3 = Error({ event_id: 'err3' });
+
+  replay['_overwriteRecordDroppedEvent']();
+
+  const client = getCurrentHub().getClient()!;
+
+  replay.handleGlobalEvent(error1);
+  replay.handleGlobalEvent(error2);
+  replay.handleGlobalEvent(error3);
+
+  client.recordDroppedEvent('before_send', 'error', { event_id: 'err2' });
+
+  // @ts-ignore private
+  expect(Array.from(replay.context.errorIds)).toEqual(['err1', 'err3']);
+
+  replay['_restoreRecordDroppedEvent']();
+});
+
 it('tags errors and transactions with replay id for session samples', async () => {
   ({ replay } = await resetSdkMock({
     sessionSampleRate: 1.0,