UNPKG

1.28 kBJavaScriptView Raw
1"use strict";
2
3Object.defineProperty(exports, "__esModule", {
4 value: true
5});
6exports.promisify = promisify;
7
8// Copyright 2017-2022 @polkadot/util authors & contributors
9// SPDX-License-Identifier: Apache-2.0
10
11/**
12 * @name promisify
13 * @summary Wraps an async callback into a `Promise`
14 * @description
15 * Wraps the supplied async function `fn` that has a standard JS callback `(error: Error, result: any)` into a `Promise`, passing the supplied parameters. When `error` is set, the Promise is rejected, else the Promise resolves with the `result` value.
16 * @example
17 * <BR>
18 *
19 * ```javascript
20 * const { promisify } from '@polkadot/util';
21 *
22 * await promisify(null, ((a, cb) => cb(null, a), true); // resolves with `true`
23 * await promisify(null, (cb) => cb(new Error('error!'))); // rejects with `error!`
24 * ```
25 */
26// eslint-disable-next-line @typescript-eslint/no-explicit-any
27function promisify(self, fn) {
28 for (var _len = arguments.length, params = new Array(_len > 2 ? _len - 2 : 0), _key = 2; _key < _len; _key++) {
29 params[_key - 2] = arguments[_key];
30 }
31
32 return new Promise((resolve, reject) => {
33 fn.apply(self, params.concat((error, result) => {
34 if (error) {
35 reject(error);
36 } else {
37 resolve(result);
38 }
39 }));
40 });
41}
\No newline at end of file