Simple deferred

deferred.js

(() => {
  
  'use strict';

  function Deferred() {
  
    this.promise = new Promise((resolve, reject) => {
  
      this.resolve = resolve;
      this.reject = reject;
    
    });
  
  }


  let d = new Deferred();

  d.promise.then(() => {
  
    console.log('done!');
  
  }).catch(() => {
  
    console.log('error!')
  
  });

  d.resolve();
  
}());