chore: import upstream snapshot with attribution

extensions/github-authentication/src/common/utils.ts

@@ -0,0 +1,118 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { EventEmitter, Event, Disposable } from 'vscode';
+
+export function filterEvent<T>(event: Event<T>, filter: (e: T) => boolean): Event<T> {
+	return (listener, thisArgs = null, disposables?) => event(e => filter(e) && listener.call(thisArgs, e), null, disposables);
+}
+
+export function onceEvent<T>(event: Event<T>): Event<T> {
+	return (listener, thisArgs = null, disposables?) => {
+		const result = event(e => {
+			result.dispose();
+			return listener.call(thisArgs, e);
+		}, null, disposables);
+
+		return result;
+	};
+}
+
+
+export interface PromiseAdapter<T, U> {
+	(
+		value: T,
+		resolve:
+			(value: U | PromiseLike<U>) => void,
+		reject:
+			(reason: any) => void
+	): any;
+}
+
+const passthrough = (value: any, resolve: (value?: any) => void) => resolve(value);
+
+/**
+ * Return a promise that resolves with the next emitted event, or with some future
+ * event as decided by an adapter.
+ *
+ * If specified, the adapter is a function that will be called with
+ * `(event, resolve, reject)`. It will be called once per event until it resolves or
+ * rejects.
+ *
+ * The default adapter is the passthrough function `(value, resolve) => resolve(value)`.
+ *
+ * @param event the event
+ * @param adapter controls resolution of the returned promise
+ * @returns a promise that resolves or rejects as specified by the adapter
+ */
+export function promiseFromEvent<T, U>(
+	event: Event<T>,
+	adapter: PromiseAdapter<T, U> = passthrough): { promise: Promise<U>; cancel: EventEmitter<void> } {
+	let subscription: Disposable;
+	const cancel = new EventEmitter<void>();
+	return {
+		promise: new Promise<U>((resolve, reject) => {
+			cancel.event(_ => reject('Cancelled'));
+			subscription = event((value: T) => {
+				try {
+					Promise.resolve(adapter(value, resolve, reject))
+						.catch(reject);
+				} catch (error) {
+					reject(error);
+				}
+			});
+		}).then(
+			(result: U) => {
+				subscription.dispose();
+				return result;
+			},
+			error => {
+				subscription.dispose();
+				throw error;
+			}
+		),
+		cancel
+	};
+}
+
+export function arrayEquals<T>(one: ReadonlyArray<T> | undefined, other: ReadonlyArray<T> | undefined, itemEquals: (a: T, b: T) => boolean = (a, b) => a === b): boolean {
+	if (one === other) {
+		return true;
+	}
+
+	if (!one || !other) {
+		return false;
+	}
+
+	if (one.length !== other.length) {
+		return false;
+	}
+
+	for (let i = 0, len = one.length; i < len; i++) {
+		if (!itemEquals(one[i], other[i])) {
+			return false;
+		}
+	}
+
+	return true;
+}
+
+
+export class StopWatch {
+
+	private _startTime: number = Date.now();
+	private _stopTime: number = -1;
+
+	public stop(): void {
+		this._stopTime = Date.now();
+	}
+
+	public elapsed(): number {
+		if (this._stopTime !== -1) {
+			return this._stopTime - this._startTime;
+		}
+		return Date.now() - this._startTime;
+	}
+}