New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

mixins.bar.js

import Ember from 'ember';

export default Ember.Mixin.create({
	beforeModel() {
    console.log('[barMixin] beforeModel')
  }
})

mixins.foo.js

import Ember from 'ember';

export default Ember.Mixin.create({
	beforeModel() {
    console.log('[fooMixin] beforeModel')
  }
})

routes.index.js

import Ember from 'ember';
import Foo from '../mixins/foo';
import Bar from '../mixins/bar';

export default Ember.Route.extend(Foo, Bar, {
  // uncomment below to see that mixins got overriden
  /*
  beforeModel() { 
    console.log('route before model')
  }
  */
});

templates.application.hbs

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

twiddle.json

{
  "version": "0.8.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.5.1",
    "ember-data": "2.5.2",
    "ember-template-compiler": "2.5.1"
  }
}