fix(replay): Start replay immediately, not in next tick

This should hopefully fix some race conditions...

.github/workflows/build.yml

@@ -761,6 +761,7 @@ jobs:
           - loader_debug
           - loader_tracing
           - loader_replay
+          - loader_replay_buffer
           - loader_tracing_replay
 
     steps:

dev-packages/browser-integration-tests/loader-suites/loader/noOnLoad/replay/test.ts

@@ -4,7 +4,8 @@ import { sentryTest } from '../../../../utils/fixtures';
 import { getReplayEvent, shouldSkipReplayTest, waitForReplayRequest } from '../../../../utils/replayHelpers';
 
 sentryTest('should capture a replay', async ({ getLocalTestUrl, page }) => {
-  if (shouldSkipReplayTest()) {
+  // When in buffer mode, there will not be a replay by default
+  if (shouldSkipReplayTest() || process.env.PW_BUNDLE === 'loader_replay_buffer') {
     sentryTest.skip();
   }
 

dev-packages/browser-integration-tests/loader-suites/loader/noOnLoad/replayError/subject.js

@@ -0,0 +1 @@
+window.doSomethingWrong();

dev-packages/browser-integration-tests/loader-suites/loader/noOnLoad/replayError/test.ts

@@ -0,0 +1,35 @@
+import { expect } from '@playwright/test';
+
+import { sentryTest } from '../../../../utils/fixtures';
+import { envelopeRequestParser, waitForErrorRequestOnUrl } from '../../../../utils/helpers';
+import { getReplayEvent, shouldSkipReplayTest, waitForReplayRequest } from '../../../../utils/replayHelpers';
+
+sentryTest('should capture a replay & attach an error', async ({ getLocalTestUrl, page }) => {
+  if (shouldSkipReplayTest()) {
+    sentryTest.skip();
+  }
+
+  await page.route('https://dsn.ingest.sentry.io/**/*', route => {
+    return route.fulfill({
+      status: 200,
+      contentType: 'application/json',
+      body: JSON.stringify({ id: 'test-id' }),
+    });
+  });
+
+  const req = waitForReplayRequest(page);
+
+  const url = await getLocalTestUrl({ testDir: __dirname });
+  const reqError = await waitForErrorRequestOnUrl(page, url);
+
+  const errorEventData = envelopeRequestParser(reqError);
+  expect(errorEventData.exception?.values?.length).toBe(1);
+  expect(errorEventData.exception?.values?.[0]?.value).toBe('window.doSomethingWrong is not a function');
+
+  const eventData = getReplayEvent(await req);
+
+  expect(eventData).toBeDefined();
+  expect(eventData.segment_id).toBe(0);
+
+  expect(errorEventData.tags?.replayId).toEqual(eventData.replay_id);
+});

dev-packages/browser-integration-tests/loader-suites/loader/onLoad/customReplay/init.js

@@ -6,5 +6,7 @@ Sentry.onLoad(function () {
         useCompression: false,
       }),
     ],
+
+    replaysSessionSampleRate: 1,
   });
 });

dev-packages/browser-integration-tests/loader-suites/loader/onLoad/replay/init.js

@@ -1,3 +1,5 @@
 Sentry.onLoad(function () {
-  Sentry.init({});
+  Sentry.init({
+    replaysSessionSampleRate: 1,
+  });
 });

dev-packages/browser-integration-tests/package.json

@@ -32,6 +32,7 @@
     "test:loader:eager": "PW_BUNDLE=loader_eager yarn test:loader",
     "test:loader:tracing": "PW_BUNDLE=loader_tracing yarn test:loader",
     "test:loader:replay": "PW_BUNDLE=loader_replay yarn test:loader",
+    "test:loader:replay_buffer": "PW_BUNDLE=loader_replay_buffer yarn test:loader",
     "test:loader:full": "PW_BUNDLE=loader_tracing_replay yarn test:loader",
     "test:loader:debug": "PW_BUNDLE=loader_debug yarn test:loader",
     "test:ci": "yarn test:all --reporter='line'",

dev-packages/browser-integration-tests/suites/replay/errors/immediateError/subject.js

@@ -0,0 +1 @@
+window.doSomethingWrong();

dev-packages/browser-integration-tests/suites/replay/errors/immediateError/test.ts

@@ -0,0 +1,38 @@
+import { expect } from '@playwright/test';
+
+import { sentryTest } from '../../../../utils/fixtures';
+import { envelopeRequestParser, waitForErrorRequestOnUrl } from '../../../../utils/helpers';
+import { getReplayEvent, shouldSkipReplayTest, waitForReplayRequest } from '../../../../utils/replayHelpers';
+
+sentryTest(
+  '[error-mode] should capture error that happens immediately after init',
+  async ({ getLocalTestUrl, page }) => {
+    if (shouldSkipReplayTest()) {
+      sentryTest.skip();
+    }
+
+    await page.route('https://dsn.ingest.sentry.io/**/*', route => {
+      return route.fulfill({
+        status: 200,
+        contentType: 'application/json',
+        body: JSON.stringify({ id: 'test-id' }),
+      });
+    });
+
+    const req = waitForReplayRequest(page);
+
+    const url = await getLocalTestUrl({ testDir: __dirname });
+    const reqError = await waitForErrorRequestOnUrl(page, url);
+
+    const errorEventData = envelopeRequestParser(reqError);
+    expect(errorEventData.exception?.values?.length).toBe(1);
+    expect(errorEventData.exception?.values?.[0]?.value).toBe('window.doSomethingWrong is not a function');
+
+    const eventData = getReplayEvent(await req);
+
+    expect(eventData).toBeDefined();
+    expect(eventData.segment_id).toBe(0);
+
+    expect(errorEventData.tags?.replayId).toEqual(eventData.replay_id);
+  },
+);

dev-packages/browser-integration-tests/utils/generatePlugin.ts

@@ -55,6 +55,7 @@ const BUNDLE_PATHS: Record<string, Record<string, string>> = {
     loader_debug: 'build/bundles/bundle.debug.min.js',
     loader_tracing: 'build/bundles/bundle.tracing.min.js',
     loader_replay: 'build/bundles/bundle.replay.min.js',
+    loader_replay_buffer: 'build/bundles/bundle.replay.min.js',
     loader_tracing_replay: 'build/bundles/bundle.tracing.replay.debug.min.js',
   },
   integrations: {
@@ -96,6 +97,10 @@ export const LOADER_CONFIGS: Record<string, { options: Record<string, unknown>;
     options: { replaysSessionSampleRate: 1, replaysOnErrorSampleRate: 1 },
     lazy: false,
   },
+  loader_replay_buffer: {
+    options: { replaysSessionSampleRate: 0, replaysOnErrorSampleRate: 1 },
+    lazy: false,
+  },
   loader_tracing_replay: {
     options: { tracesSampleRate: 1, replaysSessionSampleRate: 1, replaysOnErrorSampleRate: 1, debug: true },
     lazy: false,
@@ -128,8 +133,9 @@ function generateSentryAlias(): Record<string, string> {
 
       const modulePath = path.resolve(PACKAGES_DIR, packageName);
 
-      if (useCompiledModule && bundleKey && BUNDLE_PATHS[packageName]?.[bundleKey]) {
-        const bundlePath = path.resolve(modulePath, BUNDLE_PATHS[packageName][bundleKey]);
+      const bundleKeyPath = bundleKey && BUNDLE_PATHS[packageName]?.[bundleKey];
+      if (useCompiledModule && bundleKeyPath) {
+        const bundlePath = path.resolve(modulePath, bundleKeyPath);
 
         return [packageJSON['name'], bundlePath];
       }

packages/replay-internal/src/integration.ts

@@ -221,16 +221,7 @@ export class Replay implements Integration {
     }
 
     this._setup();
-
-    // Once upon a time, we tried to create a transaction in `setupOnce` and it would
-    // potentially create a transaction before some native SDK integrations have run
-    // and applied their own global event processor. An example is:
-    // https://github.com/getsentry/sentry-javascript/blob/b47ceafbdac7f8b99093ce6023726ad4687edc48/packages/browser/src/integrations/useragent.ts
-    //
-    // So we call `this._initialize()` in next event loop as a workaround to wait for other
-    // global event processors to finish. This is no longer needed, but keeping it
-    // here to avoid any future issues.
-    setTimeout(() => this._initialize());
+    this._initialize();
   }
 
   /**