Add cancellable promise to Microsoft auth flows (#211495)

Fixes #211406

extensions/microsoft-authentication/src/common/async.ts

@@ -3,7 +3,7 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { Disposable } from 'vscode';
+import { CancellationError, CancellationToken, Disposable } from 'vscode';
 
 export class SequencerByKey<TKey> {
 
@@ -47,3 +47,36 @@ export class IntervalTimer extends Disposable {
 		}, interval);
 	}
 }
+
+/**
+ * Returns a promise that rejects with an {@CancellationError} as soon as the passed token is cancelled.
+ * @see {@link raceCancellation}
+ */
+export function raceCancellationError<T>(promise: Promise<T>, token: CancellationToken): Promise<T> {
+	return new Promise((resolve, reject) => {
+		const ref = token.onCancellationRequested(() => {
+			ref.dispose();
+			reject(new CancellationError());
+		});
+		promise.then(resolve, reject).finally(() => ref.dispose());
+	});
+}
+
+export class TimeoutError extends Error {
+	constructor() {
+		super('Timed out');
+	}
+}
+
+export function raceTimeoutError<T>(promise: Promise<T>, timeout: number): Promise<T> {
+	return new Promise((resolve, reject) => {
+		const ref = setTimeout(() => {
+			reject(new CancellationError());
+		}, timeout);
+		promise.then(resolve, reject).finally(() => clearTimeout(ref));
+	});
+}
+
+export function raceCancellationAndTimeoutError<T>(promise: Promise<T>, token: CancellationToken, timeout: number): Promise<T> {
+	return raceCancellationError(raceTimeoutError(promise, timeout), token);
+}