fix: memory leak in integrated browser inspector sessions

[Simon Siefke (SimonSiefke)]

Details

When a cross-site iframe closes, the integrated browser removes its frame inspector but leaves the session event listener in the browser inspector's disposable store. The session and its callbacks remain there until the whole browser closes.

Change

Group event and close listeners by session and dispose that group when the session closes. Ignore late session results and attachments after disposal.

Before

Creating and removing a cross-site iframe 37 times adds 37 old DebugSession objects and two sets of 37 callbacks in the main process.

After

No more inspector-session or matching callback growth is detected in the same 37-cycle test.

Test Video

Seven iframe creation and removal cycles in the integrated browser.

test.mp4

_{AI disclosure: Model: GPT 6 Astra. Worktime: 31 min}

[vs-code-engineering]

📬 CODENOTIFY

The following users are being notified based on files changed in this PR:

Kyle Cutler (@kycutler)

Matched files:

• src/vs/platform/browserView/electron-main/browserViewInspector.ts
• src/vs/platform/browserView/test/electron-main/browserViewInspector.test.ts

Joaquín Ruales (@jruales)

Matched files:

• src/vs/platform/browserView/electron-main/browserViewInspector.ts
• src/vs/platform/browserView/test/electron-main/browserViewInspector.test.ts

[Copilot]

Copilot review overview

🟡 Changes recommended

The late evaluation-result path needs a regression test to prevent reintroducing stale session retention.

Review effort: Balanced
Findings: 1

Open (1)

• Add regression test for late Runtime.evaluate after session close · New

What changed in this PR

Fixes inspector-session listener retention when cross-origin iframes close.

Changes:

• Tracks listeners in per-session disposable stores.
• Cleans listeners on session closure and ignores late asynchronous results.
• Adds lifecycle-focused unit tests.

File	Description
browserViewInspector.ts	Adds session-scoped listener cleanup.
browserViewInspector.test.ts	Tests session and inspector disposal behavior.

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[Dmitriy Vasyura (dmitrivMS)]

Simon Siefke (@SimonSiefke) Thank you!