$.Deferred Alternative using Promises

deferred-promises.js

function Deferred( executor ){
  var self = this;

  this._promise = new Promise(function(resolve, reject){
    self._resolver = resolve;
    self._rejector = reject;

    if( typeof executor === 'function' ){
      executor(resolve, rejector)
    }

  });

}

Deferred.all = function(deferreds){

  var promises = deferreds.map(function(d){
    return d.promise();
  });

  return Promise.all(promises)
}


Object.assign(Deferred.prototype, {

  promise : function(){
    return this._promise;
  },

  //returns promise
  then : function(cb){
    return this._promise.then(cb);
  },

  //returns promise
  catch : function(){
    return this._promise.catch(cb);
  },

  finally : function(){
    return this._promise.finally(cb);
  },

  //returns Deferred
  done : function(cb){
    this._promise.then(cb);
    return this;
  },
  
  //returns Deferred
  fail : function(cb){
    this._promise.catch(cb);
    return this;
  },

  resolve : function(value){
    this.resolved = true;
    this._resolver(value);
    return this;
  },

  reject : function(){
    this._rejector(value)
    return this;
  }

})