From 35648dd011439787c3303376bc6df7e6e4cf0e42 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20Z=C3=BCnd?= <szuend@chromium.org>
Date: Tue, 3 Feb 2026 07:33:48 +0100
Subject: [PATCH] chore: emit UncaughtError events for Runtime.exceptionThrown

---
 src/PageCollector.ts        | 21 +++++++++++++++++++++
 tests/PageCollector.test.ts | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/src/PageCollector.ts b/src/PageCollector.ts
index 323d7fdbe..c68e9bacd 100644
--- a/src/PageCollector.ts
+++ b/src/PageCollector.ts
@@ -22,8 +22,19 @@ import {
   type PageEvents as PuppeteerPageEvents,
 } from './third_party/index.js';
 
+export class UncaughtError {
+  readonly message: string;
+  readonly stackTrace?: Protocol.Runtime.StackTrace;
+
+  constructor(message: string, stackTrace?: Protocol.Runtime.StackTrace) {
+    this.message = message;
+    this.stackTrace = stackTrace;
+  }
+}
+
 interface PageEvents extends PuppeteerPageEvents {
   issue: DevTools.AggregatedIssue;
+  uncaughtError: UncaughtError;
 }
 
 export type ListenerMap<EventMap extends PageEvents = PageEvents> = {
@@ -272,6 +283,7 @@ class PageIssueSubscriber {
     this.#resetIssueAggregator();
     this.#page.on('framenavigated', this.#onFrameNavigated);
     this.#session.on('Audits.issueAdded', this.#onIssueAdded);
+    this.#session.on('Runtime.exceptionThrown', this.#onExceptionThrown);
     try {
       await this.#session.send('Audits.enable');
     } catch (error) {
@@ -284,6 +296,7 @@ class PageIssueSubscriber {
     this.#seenIssues.clear();
     this.#page.off('framenavigated', this.#onFrameNavigated);
     this.#session.off('Audits.issueAdded', this.#onIssueAdded);
+    this.#session.off('Runtime.exceptionThrown', this.#onExceptionThrown);
     if (this.#issueAggregator) {
       this.#issueAggregator.removeEventListener(
         DevTools.IssueAggregatorEvents.AGGREGATED_ISSUE_UPDATED,
@@ -305,6 +318,14 @@ class PageIssueSubscriber {
     this.#page.emit('issue', event.data);
   };
 
+  #onExceptionThrown = (event: Protocol.Runtime.ExceptionThrownEvent) => {
+    const {exception, text, stackTrace} = event.exceptionDetails;
+    const messageWithRest = exception?.description?.split('\n    at ', 2) ?? [];
+    const message = text + ' ' + (messageWithRest[0] ?? '');
+
+    this.#page.emit('uncaughtError', new UncaughtError(message, stackTrace));
+  };
+
   // On navigation, we reset issue aggregation.
   #onFrameNavigated = (frame: Frame) => {
     // Only split the storage on main frame navigation
diff --git a/tests/PageCollector.test.ts b/tests/PageCollector.test.ts
index 41e769c47..0c49d435d 100644
--- a/tests/PageCollector.test.ts
+++ b/tests/PageCollector.test.ts
@@ -382,4 +382,36 @@ describe('ConsoleCollector', () => {
     assert.equal(collectedIssue.code(), 'MixedContentIssue');
     assert.equal(collectedIssue.getAggregatedIssuesCount(), 1);
   });
+
+  it('emits UncaughtErrors for Runtime.exceptionThrown CDP events', async () => {
+    const browser = getMockBrowser();
+    const page = (await browser.pages())[0];
+    // @ts-expect-error internal API.
+    const cdpSession = page._client();
+    const onUncaughtErrorListener = sinon.spy();
+    const collector = new ConsoleCollector(browser, () => {
+      return {
+        uncaughtError: onUncaughtErrorListener,
+      } as ListenerMap;
+    });
+    await collector.init([page]);
+
+    cdpSession.emit('Runtime.exceptionThrown', {
+      exceptionDetails: {
+        exception: {description: 'SyntaxError: Expected {'},
+        text: 'Uncaught',
+        stackTrace: {callFrames: []},
+      },
+    });
+
+    sinon.assert.calledOnceWithMatch(
+      onUncaughtErrorListener,
+      sinon.match(e => {
+        return (
+          e.message === 'Uncaught SyntaxError: Expected {' &&
+          e.stackTrace.callFrames.length === 0
+        );
+      }),
+    );
+  });
 });