lifecycle - emit onWillKill when app.exit

src/vs/platform/lifecycle/electron-main/lifecycleMainService.ts

@@ -91,6 +91,13 @@ export interface ILifecycleMainService {
 	 */
 	readonly onBeforeCloseWindow: Event<ICodeWindow>;
 
+	/**
+	 * An event that fires in the rare cases where `app.exit` is triggered
+	 * and thus we Forcefully shutdown the application. No other lifecycle
+	 * event handlers are triggered.
+	 */
+	readonly onWillKill: Event<void>;
+
 	/**
 	 * Make a `ICodeWindow` known to the lifecycle main service.
 	 */
@@ -117,7 +124,8 @@ export interface ILifecycleMainService {
 	quit(willRestart?: boolean): Promise<boolean /* veto */>;
 
 	/**
-	 * Forcefully shutdown the application. No livecycle event handlers are triggered.
+	 * Forcefully shutdown the application. The only lifecycle event handler
+	 * that is triggered is `onWillKill`.
 	 */
 	kill(code?: number): Promise<void>;
 
@@ -169,6 +177,9 @@ export class LifecycleMainService extends Disposable implements ILifecycleMainSe
 	private readonly _onBeforeUnloadWindow = this._register(new Emitter<IWindowUnloadEvent>());
 	readonly onBeforeUnloadWindow = this._onBeforeUnloadWindow.event;
 
+	private readonly _onWillKill = this._register(new Emitter<void>());
+	readonly onWillKill = this._onWillKill.event;
+
 	private _quitRequested = false;
 	get quitRequested(): boolean { return this._quitRequested; }
 
@@ -589,6 +600,9 @@ export class LifecycleMainService extends Disposable implements ILifecycleMainSe
 	async kill(code?: number): Promise<void> {
 		this.logService.trace('Lifecycle#kill()');
 
+		// Event
+		this._onWillKill.fire();
+
 		// The kill() method is only used in 2 situations:
 		// - when an instance fails to start at all
 		// - when extension tests run from CLI to report proper exit code

src/vs/platform/storage/test/electron-main/storageMainService.test.ts

@@ -57,6 +57,7 @@ suite('StorageMainService', function () {
 		onWillLoadWindow = Event.None;
 		onBeforeCloseWindow = Event.None;
 		onBeforeUnloadWindow = Event.None;
+		onWillKill = Event.None;
 
 		wasRestarted = false;
 		quitRequested = false;