README.md

JavaScript Deferred Promise

A copy-paste friendly implementation of the deferred promise pattern ready for you to use, because this pattern is useful no matter what others may tell you.

export default class Deferred extends Promise {
  constructor() {
    let _resolve;
    let _reject;
    super((resolve, reject) => {
      _resolve = resolve;
      _reject = reject;
    });

    this.resolve = _resolve;
    this.reject = _reject;
  }
}

Deferred.prototype.constructor = Promise;

https://stackoverflow.com/a/48159603/2715716