scratch.js

import Ember from 'ember';

const PromisableArrayProxy = Ember.ArrayProxy.extend(Ember.PromiseProxyMixin);

export default function(...args) {
  const fn = args.pop();
  const dependentKeys = args.slice();

  return Ember.computed(...dependentKeys, function() {
    const promise = fn.apply(this);

    return PromisableArrayProxy.create({
      promise: Ember.RSVP.resolve(promise)
    });
  });
}

// invoke like
//
// myArray: asyncArrayProxy('depkeys', function(){
// 	return this.store.findAll('posts');
// });