ember-concurrency-test

application.controller.js

import Ember from 'ember';
import { task } from 'ember-concurrency';

export default Ember.Controller.extend({

  parentTask: task(function *() {
		yield this.get('childTask').perform();
  }),
  
  childTask: task(function *() {
    throw new Error('error');
  })
});

application.template.hbs

<h1>Double Thrown Error</h1>
<button {{action (perform parentTask)}}>perform</button>

twiddle.json

{
  "version": "0.7.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.5.1/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.5.2/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.5.1/ember-template-compiler.js",
    "babel-polyfill":"https://cdn.rawgit.com/nicksrandall/babel-polyfill/master/browser-polyfill.js"
  },
  "addons": {
    "ember-concurrency": "0.6.0"
  }
}