New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  doSomething: task(function*() {
    return yield 'task result';
  }),
  
  runTask: task(function*(es5Getter) {
    this.set('result', '');
    try {
      if (es5Getter) {
        this.set('result', yield this.doSomething.perform());
      } else {
        this.set('result', yield this.get('doSomething').perform());
      }
    } catch (e) {
      this.set('result', `ERROR: ${e}`);
    }
  })
});

templates.application.hbs

<button onclick={{perform this.runTask}}>Run task</button>
<br>
<button onclick={{perform this.runTask}}>Run task using ES5 getter</button>
<br>
result: {{result}}

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "canary",
    "ember-template-compiler": "canary",
    "ember-testing": "canary"
  },
  "addons": {
    "ember-concurrency": "0.8.19"
  }
}