asyncio-like Future for JavaScript

future.js

/**
 * A future similar to Python's asyncio.Future. Allows to resolve or reject
 * outside of the executor.
 */
class Future extends Promise {
  constructor(executor) {
    let resolve, reject;
    super((resolve_, reject_) => {
      resolve = resolve_;
      reject = reject_;
      if (executor) {
        return executor(resolve_, reject_);
      }
    });

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

  get done() {
    return this._done;
  }
  
  resolve(...args) {
    this._done = true;
    return this._resolve(...args);
  }

  reject(...args) {
    this._done = true;
    return this._reject(...args);
  }
}