name : promiseCallback.js 'use strict'; Object.defineProperty(exports, "__esModule", { value: true }); const PROMISE_SYMBOL = Symbol('promiseCallback'); function promiseCallback() { let resolve, reject; function callback(err, ...args) { if (err) return reject(err); resolve(args.length > 1 ? args : args[0]); } callback[PROMISE_SYMBOL] = new Promise((res, rej) => { resolve = res, reject = rej; }); return callback; } exports.promiseCallback = promiseCallback; exports.PROMISE_SYMBOL = PROMISE_SYMBOL;