Hrmm

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  noChange: function() {
    return 'foo';
  }.property(),
  
  butWhy: function() {
    console.log('changed!')
    return this.get('noChange') + ' wat';
  }.property('noChange'),
  
  actions: {
    changeTheThing: function() {
      this.set('noChange', this.get('noChange'));
    },
    
    changeTheThingRandom: function() {
      this.set('noChange', Math.random().toString())
    }
  }
});

templates.application.hbs

<p>{{noChange}}
{{butWhy}}</p>
<button {{action "changeTheThing"}}>Same</button>
<button {{action "changeTheThingRandom"}}>Change</button>

twiddle.json

{
  "version": "0.10.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "1.12.2",
    "ember-data": "1.13.15",
    "ember-template-compiler": "1.12.2"
  },
  "addons": {}
}