fix: don't throw resolving browser view dynamic events after view destroyed (fixes #333783)

src/vs/platform/browserView/electron-main/browserViewMainService.ts

@@ -4,7 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { Emitter, Event } from '../../../base/common/event.js';
-import { Disposable, DisposableMap } from '../../../base/common/lifecycle.js';
+import { Disposable, DisposableMap, toDisposable } from '../../../base/common/lifecycle.js';
 import { VSBuffer } from '../../../base/common/buffer.js';
 import { BrowserViewSessionSelector, IBrowserElementCommentsUpdate, IBrowserElementSelectionOptions, IBrowserViewAudience, IBrowserViewBounds, IBrowserViewState, IBrowserViewService, IBrowserViewCaptureScreenshotOptions, IBrowserViewFindInPageOptions, BrowserViewCommandId, IBrowserViewOwner, IBrowserViewInfo, IBrowserViewCreatedEvent, IBrowserViewEditorOpenOptions, IBrowserViewCreateOptions, IBrowserViewCreationContext, IBrowserViewWindowConfiguration, IBrowserDeviceProfile } from '../common/browserView.js';
 import { clipboard, Menu, MenuItem } from 'electron';
@@ -124,6 +124,37 @@ export class BrowserViewMainService extends Disposable implements IBrowserViewMa
 		return view;
 	}
 
+	/**
+	 * Resolve a dynamic event for a browser view, returning {@link Event.None}
+	 * when the view no longer exists. A missing view is an expected IPC
+	 * subscription race (the view can be destroyed before the renderer's
+	 * `listen` request is handled), not a bug, so the getter must not throw.
+	 */
+	private _getBrowserViewEvent<T>(id: string, getEvent: (view: BrowserView) => Event<T>): Event<T> {
+		const view = this.browserViews.get(id);
+		if (!view) {
+			return Event.None;
+		}
+		return getEvent(view);
+	}
+
+	/**
+	 * An event that fires `void` once for every subscriber, on the next tick.
+	 * Used for the terminal `onDidClose` event when the view is already gone,
+	 * so a consumer that lost the IPC subscription race still receives a single
+	 * close notification and tears down its stale editor/model.
+	 */
+	private readonly _onceClosed: Event<void> = (listener, thisArgs?, disposables?) => {
+		const handle = setTimeout(() => listener.call(thisArgs));
+		const disposable = toDisposable(() => clearTimeout(handle));
+		if (Array.isArray(disposables)) {
+			disposables.push(disposable);
+		} else if (disposables) {
+			disposables.add(disposable);
+		}
+		return disposable;
+	};
+
 	private _getViewInfo(view: BrowserView): IBrowserViewInfo {
 		return {
 			id: view.id,
@@ -146,83 +177,88 @@ export class BrowserViewMainService extends Disposable implements IBrowserViewMa
 	}
 
 	onDynamicDidNavigate(id: string) {
-		return this._getBrowserView(id).onDidNavigate;
+		return this._getBrowserViewEvent(id, view => view.onDidNavigate);
 	}
 
 	onDynamicDidChangeLoadingState(id: string) {
-		return this._getBrowserView(id).onDidChangeLoadingState;
+		return this._getBrowserViewEvent(id, view => view.onDidChangeLoadingState);
 	}
 
 	onDynamicDidChangeFocus(id: string) {
-		return this._getBrowserView(id).onDidChangeFocus;
+		return this._getBrowserViewEvent(id, view => view.onDidChangeFocus);
 	}
 
 	onDynamicDidChangeVisibility(id: string) {
-		return this._getBrowserView(id).onDidChangeVisibility;
+		return this._getBrowserViewEvent(id, view => view.onDidChangeVisibility);
 	}
 
 	onDynamicDidChangeDevToolsState(id: string) {
-		return this._getBrowserView(id).onDidChangeDevToolsState;
+		return this._getBrowserViewEvent(id, view => view.onDidChangeDevToolsState);
 	}
 
 	onDynamicDidKeyCommand(id: string) {
-		return this._getBrowserView(id).onDidKeyCommand;
+		return this._getBrowserViewEvent(id, view => view.onDidKeyCommand);
 	}
 
 	onDynamicDidChangeTitle(id: string) {
-		return this._getBrowserView(id).onDidChangeTitle;
+		return this._getBrowserViewEvent(id, view => view.onDidChangeTitle);
 	}
 
 	onDynamicDidChangeFavicon(id: string) {
-		return this._getBrowserView(id).onDidChangeFavicon;
+		return this._getBrowserViewEvent(id, view => view.onDidChangeFavicon);
 	}
 
 	onDynamicDidFindInPage(id: string) {
-		return this._getBrowserView(id).onDidFindInPage;
+		return this._getBrowserViewEvent(id, view => view.onDidFindInPage);
 	}
 
 	onDynamicDidClose(id: string) {
-		return this._getBrowserView(id).onDidClose;
+		const view = this.browserViews.get(id);
+		if (!view) {
+			// Terminal event: emit one close so a consumer that lost the IPC race still tears down its stale editor/model.
+			return this._onceClosed;
+		}
+		return view.onDidClose;
 	}
 
 	onDynamicDidSelectElement(id: string) {
-		return this._getBrowserView(id).inspector.onDidSelectElement;
+		return this._getBrowserViewEvent(id, view => view.inspector.onDidSelectElement);
 	}
 
 	onDynamicDidRemoveElementComment(id: string) {
-		return this._getBrowserView(id).inspector.onDidRemoveElementComment;
+		return this._getBrowserViewEvent(id, view => view.inspector.onDidRemoveElementComment);
 	}
 
 	onDynamicDidChangeElementSelectionState(id: string) {
-		return this._getBrowserView(id).inspector.onDidChangeElementSelectionState;
+		return this._getBrowserViewEvent(id, view => view.inspector.onDidChangeElementSelectionState);
 	}
 
 	onDynamicDidPickArea(id: string) {
-		return this._getBrowserView(id).inspector.onDidPickArea;
+		return this._getBrowserViewEvent(id, view => view.inspector.onDidPickArea);
 	}
 
 	onDynamicDidChangeAreaSelectionActive(id: string) {
-		return this._getBrowserView(id).inspector.onDidChangeAreaSelectionActive;
+		return this._getBrowserViewEvent(id, view => view.inspector.onDidChangeAreaSelectionActive);
 	}
 
 	onDynamicDidChangeDeviceEmulation(id: string) {
-		return this._getBrowserView(id).emulator.onDidChange;
+		return this._getBrowserViewEvent(id, view => view.emulator.onDidChange);
 	}
 
 	onDynamicDidChangeRemoteStatus(id: string) {
-		return this._getBrowserView(id).onDidChangeRemoteStatus;
+		return this._getBrowserViewEvent(id, view => view.onDidChangeRemoteStatus);
 	}
 
 	onDynamicDidChangeAudiences(id: string) {
-		return this._getBrowserView(id).onDidChangeAudiences;
+		return this._getBrowserViewEvent(id, view => view.onDidChangeAudiences);
 	}
 
 	onDynamicDidRequestPermission(id: string) {
-		return this._getBrowserView(id).onDidRequestPermission;
+		return this._getBrowserViewEvent(id, view => view.onDidRequestPermission);
 	}
 
 	onDynamicDidChangePermissions(id: string) {
-		return this._getBrowserView(id).onDidChangePermissions;
+		return this._getBrowserViewEvent(id, view => view.onDidChangePermissions);
 	}
 
 	async getState(id: string): Promise<IBrowserViewState> {