Report Event.Buffer leaks when running from source

[alexdima]

No description provided.

[vs-code-engineering]

📬 CODENOTIFY

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

@bpasero

Matched files:

• src/vs/base/parts/ipc/common/ipc.ts

[Copilot]

Pull request overview

This PR enhances Event.buffer with dev-only leak diagnostics to help identify buffered events that are never consumed when running from source (VSCODE_DEV). It updates existing call sites to provide a buffer “debug name” so warnings can be attributed to a specific buffered event.

Changes:

• Extend Event.buffer to require a debugName and emit dev-only warnings when buffered events accumulate unconsumed (count/time thresholds).
• Update various call sites (terminal embedder service, extension host message port, IPC channels) to pass a debugName.
• Update Event.buffer unit tests to match the new signature.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/vs/base/common/event.ts	Adds debugName parameter to Event.buffer and implements dev-only leak warning logic.
src/vs/base/parts/ipc/common/ipc.ts	Updates ProxyChannel event buffering to pass the event name as debugName.
src/vs/base/test/common/event.test.ts	Adjusts tests to pass a debugName to Event.buffer.
src/vs/workbench/services/terminal/common/embedderTerminalService.ts	Updates buffered terminal creation event to include a debugName.
src/vs/workbench/api/common/extHostExtensionService.ts	Updates buffered message-port receive event to include a debugName.
src/vs/platform/extensionManagement/common/extensionManagementIpc.ts	Updates buffered extension management events to include debugNames.
src/vs/platform/mcp/common/mcpManagementIpc.ts	Updates buffered MCP management events to include debugNames.

Comments suppressed due to low confidence (2)

src/vs/base/parts/ipc/common/ipc.ts:1141

• Same as above: undefined is being passed as the _buffer argument to Event.buffer, but the implementation immediately does _buffer.slice(). This should be an empty array (or adjust the call/signature) to avoid compile/runtime failure.

						mapEventNameToEvent.set(event, Event.buffer(handler[event] as Event<unknown>, event, true, undefined, disposables));

src/vs/workbench/api/common/extHostExtensionService.ts:566

• This Event.buffer result becomes part of the extension-facing messagePassingProtocol. Per the Event.buffer contract, public/third-party-facing buffered events should be created with a DisposableStore so the underlying DOM listener can be cleaned up when the extension is disposed. You already have extensionInternalStore in scope; consider passing it to Event.buffer(...).

						const onDidReceiveMessage = Event.buffer(Event.fromDOMEventEmitter(messagePort, 'message', e => e.data), 'onDidReceiveMessage');
						messagePort.start();
						messagePassingProtocol = {
							onDidReceiveMessage,
							// eslint-disable-next-line local/code-no-any-casts
							postMessage: messagePort.postMessage.bind(messagePort) as any
						};