await-duration.js

class Duration {
  constructor(number) {
    this._number = number;
  }

  valueOf() {
    return this._number;
  }

  then(fn) {
    setTimeout(fn, this.valueOf());
  }
}

Object.defineProperty(Number.prototype, 'seconds', {
  enumerable: false,
  get() {
    return new Duration(this * 1000);
  }
});

console.log('Now');
setTimeout(_ => console.log('2 seconds later'), (2).seconds);

(async function doIt() {
  await (2).seconds;
  console.log('2 seconds later');
})();


/*eslint no-console: 0*/