New Twiddle

controllers.application.js

import Ember from 'ember';
import BaseController from './base';

export default BaseController.extend({
  appName: 'Ember Twiddle',
  barbaz: 'application barbaz',
  init() {
    this._super(...arguments);
    this.get('index')();
  }
});

controllers.base.js

import Ember from 'ember';
import FoobarMixin from '../mixins/foobar';

export default Ember.Controller.extend(FoobarMixin, {
  barbaz: 'base barbaz',
  init() {
    this._super(...arguments);
    this.initialize(this.get('barbaz'));
    console.log('base::init called');
  }
});

mixins.foobar.js

import Ember from 'ember';

export default Ember.Mixin.create({
  index: function() {
    console.log('index is a thing');
  },
  initialize(foo) {
    console.log('foobar::initialize', foo); 
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.10.6",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.9.0",
    "ember-data": "2.9.0",
    "ember-template-compiler": "2.9.0",
    "ember-testing": "2.9.0"
  },
  "addons": {}
}