more TS 4.1 fixes (#106358)

Author: bpasero

src/vs/base/common/async.ts

@@ -52,21 +52,21 @@ export function createCancelablePromise<T>(callback: (token: CancellationToken)
 
 export function raceCancellation<T>(promise: Promise<T>, token: CancellationToken): Promise<T | undefined>;
 export function raceCancellation<T>(promise: Promise<T>, token: CancellationToken, defaultValue: T): Promise<T>;
-export function raceCancellation<T>(promise: Promise<T>, token: CancellationToken, defaultValue?: T): Promise<T> {
-	return Promise.race([promise, new Promise<T>(resolve => token.onCancellationRequested(() => resolve(defaultValue)))]);
+export function raceCancellation<T>(promise: Promise<T>, token: CancellationToken, defaultValue?: T): Promise<T | undefined> {
+	return Promise.race([promise, new Promise<T | undefined>(resolve => token.onCancellationRequested(() => resolve(defaultValue)))]);
 }
 
-export function raceTimeout<T>(promise: Promise<T>, timeout: number, onTimeout?: () => void): Promise<T> {
-	let promiseResolve: (() => void) | undefined = undefined;
+export function raceTimeout<T>(promise: Promise<T>, timeout: number, onTimeout?: () => void): Promise<T | undefined> {
+	let promiseResolve: ((value: T | undefined) => void) | undefined = undefined;
 
 	const timer = setTimeout(() => {
-		promiseResolve?.();
+		promiseResolve?.(undefined);
 		onTimeout?.();
 	}, timeout);
 
 	return Promise.race([
 		promise.finally(() => clearTimeout(timer)),
-		new Promise<T>(resolve => promiseResolve = resolve)
+		new Promise<T | undefined>(resolve => promiseResolve = resolve)
 	]);
 }