parallel-universe/Deferred.js

The set of async flow control structures and promise utils.

'use strict';

/**
 * The promise that can be resolved externally.
 *
 * @template T The value that the promise is fulfilled with.
 */
class Deferred extends Promise {
    static get [Symbol.species]() {
        return Promise;
    }
    /**
     * Creates a new instance of {@link Deferred}.
     *
     * @template T The value that the promise is fulfilled with.
     */
    constructor() {
        let resolve;
        let reject;
        super((resolveSuper, rejectSuper) => {
            resolve = resolveSuper;
            reject = rejectSuper;
        });
        this.resolve = resolve;
        this.reject = reject;
    }
}

exports.Deferred = Deferred;