1// Copyright (C) 2018 The Android Open Source Project 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15// tslint:disable:no-any 16 17/** 18 * Promise wrapper with exposed resolve and reject callbacks. 19 */ 20export interface Deferred<T> extends Promise<T> { 21 readonly resolve: (value?: T|PromiseLike<T>) => void; 22 readonly reject: (reason?: any) => void; 23} 24 25/** 26 * Create a promise with exposed resolve and reject callbacks. 27 */ 28export function defer<T>(): Deferred<T> { 29 let resolve = null as any; 30 let reject = null as any; 31 const p = new Promise((res, rej) => [resolve, reject] = [res, rej]); 32 return Object.assign(p, {resolve, reject}) as any; 33} 34