From abadff16433ba4141048117ee1036504cbef57f0 Mon Sep 17 00:00:00 2001
From: Samuel Attard <sattard@anthropic.com>
Date: Sun, 12 Apr 2026 00:28:01 -0700
Subject: [PATCH] test: deflake 'creates unique session id for each target'

Await each CDP step in sequence and use Runtime.evaluate on the attached
session after Debugger.enable is acknowledged, so Debugger.scriptParsed is
guaranteed to fire regardless of page-load timing. 0/10 flakes (was ~3/5).
---
 spec/api-debugger.spec.ts | 58 ++++++++++++++++++++-------------------
 1 file changed, 30 insertions(+), 28 deletions(-)

diff --git a/spec/api-debugger.spec.ts b/spec/api-debugger.spec.ts
index 74f039340b..a5a767931a 100644
--- a/spec/api-debugger.spec.ts
+++ b/spec/api-debugger.spec.ts
@@ -8,7 +8,7 @@ import * as http from 'node:http';
 import * as path from 'node:path';
 
 import { emittedUntil } from './lib/events-helpers';
-import { listen, withDone } from './lib/spec-helpers';
+import { listen } from './lib/spec-helpers';
 import { closeAllWindows } from './lib/window-helpers';
 
 describe('debugger module', () => {
@@ -237,36 +237,38 @@ describe('debugger module', () => {
       w.webContents.debugger.detach();
     });
 
-    it(
-      'creates unique session id for each target',
-      withDone((done) => {
-        w.webContents.loadFile(path.join(__dirname, 'fixtures', 'sub-frames', 'debug-frames.html'));
-        w.webContents.debugger.attach();
-        let debuggerSessionId: string;
+    it('creates unique session id for each target', async () => {
+      await w.webContents.loadFile(path.join(__dirname, 'fixtures', 'sub-frames', 'debug-frames.html'));
+      w.webContents.debugger.attach();
 
-        w.webContents.debugger.on('message', (_event, ...args) => {
-          const [method, params, sessionId] = args;
+      const targetCreated = new Promise<{ targetId: string }>((resolve) => {
+        w.webContents.debugger.on('message', (_event, method, params) => {
           if (method === 'Target.targetCreated') {
-            w.webContents.debugger
-              .sendCommand('Target.attachToTarget', { targetId: params.targetInfo.targetId, flatten: true })
-              .then((result) => {
-                debuggerSessionId = result.sessionId;
-                w.webContents.debugger.sendCommand('Debugger.enable', {}, result.sessionId);
-
-                // Ensure debugger finds a script to pause to possibly reduce flaky
-                // tests.
-                w.webContents.mainFrame.executeJavaScript('void 0;');
-              });
-          }
-          if (method === 'Debugger.scriptParsed') {
-            if (sessionId === debuggerSessionId) {
-              w.webContents.debugger.detach();
-              done();
-            }
+            resolve({ targetId: params.targetInfo.targetId });
           }
         });
-        w.webContents.debugger.sendCommand('Target.setDiscoverTargets', { discover: true });
-      })
-    );
+      });
+      await w.webContents.debugger.sendCommand('Target.setDiscoverTargets', { discover: true });
+      const { targetId } = await targetCreated;
+
+      const { sessionId } = await w.webContents.debugger.sendCommand('Target.attachToTarget', {
+        targetId,
+        flatten: true
+      });
+      expect(sessionId).to.be.a('string').and.not.be.empty();
+
+      const scriptParsed = new Promise<string>((resolve) => {
+        w.webContents.debugger.on('message', (_event, method, _params, messageSessionId) => {
+          if (method === 'Debugger.scriptParsed') resolve(messageSessionId);
+        });
+      });
+      await w.webContents.debugger.sendCommand('Debugger.enable', {}, sessionId);
+      // Evaluate via CDP on the attached session so a script is parsed after
+      // Debugger.enable has been acknowledged, regardless of page load timing.
+      await w.webContents.debugger.sendCommand('Runtime.evaluate', { expression: 'void 0;' }, sessionId);
+
+      expect(await scriptParsed).to.equal(sessionId);
+      w.webContents.debugger.detach();
+    });
   });
 });