ES5 getters and ember-concurrency = ❤️

controllers.application.js

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

export default Ember.Controller.extend({
  someTask: task(function*() {
    console.log('🔥');
  }),
  
  actions: {
    performSomeTask() {
      this.someTask.perform();
    }
  }
});

templates.application.hbs

<p>
	someTask.performCount: {{this.someTask.performCount}}
</p>

<button onclick={{action "performSomeTask"}}>
  perform someTask
</button>

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": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0",
    "ember-concurrency": "0.8.19"
  }
}