New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  originalValue: 'hello bob',
  
  reads: Ember.computed.reads('originalValue'),
  
  readOnly: Ember.computed.alias('originalValue').readOnly(),
  
  alias: Ember.computed.alias('originalValue'),
  
  readOnlyTest: Ember.computed('originalValue', function() {
    return this.getAMillionTimes('readOnlyTest');
  }),
  
  
  readsTest: Ember.computed('originalValue',function() {
    return this.getAMillionTimes('reads');
  }),
  
  aliasTest: Ember.computed('originalValue',function() {
    return this.getAMillionTimes('alias');
  }),
  
  getAMillionTimes(prop) {
    let start = performance.now();
    for(let i = 0; i < 100000; i++) {
      this.get('reads');
    }
    return performance.now() - start;
  },
  
  actions: {
    run() {
      this.set('originalValue', Math.random());
    },
  },
  
  
   
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
<button {{action "run"}}>Run again</button><br />
OriginalValue: {{originalValue}}<br />
ReadOnly: {{readOnlyTest}}<br />
Reads: {{readsTest}}<br />
Alias: {{aliasTest}}
<br>
<br>

twiddle.json

{
  "version": "0.10.4",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.7.0",
    "ember-data": "2.7.0",
    "ember-template-compiler": "2.7.0"
  },
  "addons": {}
}