feat: Allow capture of more than 1 ANR event (#14684)

Adds a `maxAnrEvents` option to the ANR integration which allows you to
capture more than one event.

Author: timfish

dev-packages/node-integration-tests/suites/anr/basic-multiple.mjs

@@ -0,0 +1,36 @@
+import * as assert from 'assert';
+import * as crypto from 'crypto';
+
+import * as Sentry from '@sentry/node';
+
+global._sentryDebugIds = { [new Error().stack]: 'aaaaaaaa-aaaa-4aaa-aaaa-aaaaaaaaaa' };
+
+setTimeout(() => {
+  process.exit();
+}, 10000);
+
+Sentry.init({
+  dsn: process.env.SENTRY_DSN,
+  release: '1.0',
+  autoSessionTracking: false,
+  integrations: [Sentry.anrIntegration({ captureStackTrace: true, anrThreshold: 100, maxAnrEvents: 2 })],
+});
+
+Sentry.setUser({ email: '[email protected]' });
+Sentry.addBreadcrumb({ message: 'important message!' });
+
+function longWork() {
+  for (let i = 0; i < 20; i++) {
+    const salt = crypto.randomBytes(128).toString('base64');
+    const hash = crypto.pbkdf2Sync('myPassword', salt, 10000, 512, 'sha512');
+    assert.ok(hash);
+  }
+}
+
+setTimeout(() => {
+  longWork();
+}, 1000);
+
+setTimeout(() => {
+  longWork();
+}, 4000);

dev-packages/node-integration-tests/suites/anr/basic.mjs

@@ -30,3 +30,8 @@ function longWork() {
 setTimeout(() => {
   longWork();
 }, 1000);
+
+// Ensure we only send one event even with multiple blocking events
+setTimeout(() => {
+  longWork();
+}, 4000);

dev-packages/node-integration-tests/suites/anr/test.ts

@@ -101,7 +101,7 @@ const ANR_EVENT_WITH_DEBUG_META: Event = {
       {
         type: 'sourcemap',
         debug_id: 'aaaaaaaa-aaaa-4aaa-aaaa-aaaaaaaaaa',
-        code_file: expect.stringContaining('basic.'),
+        code_file: expect.stringContaining('basic'),
       },
     ],
   },
@@ -123,6 +123,14 @@ conditionalTest({ min: 16 })('should report ANR when event loop blocked', () =>
       .start(done);
   });
 
+  test('multiple events via maxAnrEvents', done => {
+    createRunner(__dirname, 'basic-multiple.mjs')
+      .withMockSentryServer()
+      .expect({ event: ANR_EVENT_WITH_DEBUG_META })
+      .expect({ event: ANR_EVENT_WITH_DEBUG_META })
+      .start(done);
+  });
+
   test('blocked indefinitely', done => {
     createRunner(__dirname, 'indefinite.mjs').withMockSentryServer().expect({ event: ANR_EVENT }).start(done);
   });

packages/node/src/integrations/anr/common.ts

@@ -21,6 +21,12 @@ export interface AnrIntegrationOptions {
    * This uses the node debugger which enables the inspector API and opens the required ports.
    */
   captureStackTrace: boolean;
+  /**
+   * Maximum number of ANR events to send.
+   *
+   * Defaults to 1.
+   */
+  maxAnrEvents: number;
   /**
    * Tags to include with ANR events.
    */

packages/node/src/integrations/anr/index.ts

@@ -160,6 +160,7 @@ async function _startWorker(
     pollInterval: integrationOptions.pollInterval || DEFAULT_INTERVAL,
     anrThreshold: integrationOptions.anrThreshold || DEFAULT_HANG_THRESHOLD,
     captureStackTrace: !!integrationOptions.captureStackTrace,
+    maxAnrEvents: integrationOptions.maxAnrEvents || 1,
     staticTags: integrationOptions.staticTags || {},
     contexts,
   };

packages/node/src/integrations/anr/worker.ts

@@ -23,7 +23,7 @@ type VoidFunction = () => void;
 
 const options: WorkerStartData = workerData;
 let session: Session | undefined;
-let hasSentAnrEvent = false;
+let sentAnrEvents = 0;
 let mainDebugImages: Record<string, string> = {};
 
 function log(msg: string): void {
@@ -136,11 +136,11 @@ function applyScopeToEvent(event: Event, scope: ScopeData): void {
 }
 
 async function sendAnrEvent(frames?: StackFrame[], scope?: ScopeData): Promise<void> {
-  if (hasSentAnrEvent) {
+  if (sentAnrEvents >= options.maxAnrEvents) {
     return;
   }
 
-  hasSentAnrEvent = true;
+  sentAnrEvents += 1;
 
   await sendAbnormalSession();
 
@@ -181,11 +181,13 @@ async function sendAnrEvent(frames?: StackFrame[], scope?: ScopeData): Promise<v
   await transport.send(envelope);
   await transport.flush(2000);
 
-  // Delay for 5 seconds so that stdio can flush if the main event loop ever restarts.
-  // This is mainly for the benefit of logging or debugging.
-  setTimeout(() => {
-    process.exit(0);
-  }, 5_000);
+  if (sentAnrEvents >= options.maxAnrEvents) {
+    // Delay for 5 seconds so that stdio can flush if the main event loop ever restarts.
+    // This is mainly for the benefit of logging or debugging.
+    setTimeout(() => {
+      process.exit(0);
+    }, 5_000);
+  }
 }
 
 let debuggerPause: VoidFunction | undefined;