New Twiddle

comment-list.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  _commentsModel: ['one', 'two', 'three'],
  
  // switching this to `readOnly` will blow up
  comments: Ember.computed.reads('_commentsModel')
});

comment-list.template.hbs

{{#each comments as |comment|}}
  {{comment}}
{{/each}}

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  applicationComments: ['application', ' ', 'comments']
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{comment-list comments=applicationComments}}
<br>
<br>

twiddle.json

{
  "version": "0.9.3",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.6.0",
    "ember-data": "2.6.1",
    "ember-template-compiler": "2.6.0"
  }
}