1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
// TODO(ry) It'd be better to make Deferred a class that inherits from// Promise, rather than an interface. This is possible in ES2016, however// typescript produces broken code when targeting ES5 code.// See https://github.com/Microsoft/TypeScript/issues/15202// At the time of writing, the github issue is closed but the problem remains.export interface Deferred<T> extends Promise<T> {  readonly state: "pending" | "fulfilled" | "rejected";  resolve(value?: T | PromiseLike<T>): void;  // deno-lint-ignore no-explicit-any  reject(reason?: any): void;}
/** * Creates a Promise with the `reject` and `resolve` functions placed as methods * on the promise object itself. * * @example * ```typescript * import { deferred } from "https://deno.land/std@$STD_VERSION/async/deferred.ts"; * * const p = deferred<number>(); * // ... * p.resolve(42); * ``` */export function deferred<T>(): Deferred<T> {  let methods;  let state = "pending";  const promise = new Promise<T>((resolve, reject) => {    methods = {      async resolve(value: T | PromiseLike<T>) {        await value;        state = "fulfilled";        resolve(value);      },      // deno-lint-ignore no-explicit-any      reject(reason?: any) {        state = "rejected";        reject(reason);      },    };  });  Object.defineProperty(promise, "state", { get: () => state });  return Object.assign(promise, methods) as Deferred<T>;}