Guides Bug?

application.controller.js

import Ember from 'ember';

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

application.template.hbs

{{comment-form}}

comment-form.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  comment: '',

  actions: {
    submitComment() {
      this.get('submitComment')({ comment: this.get('comment') });
    }
  }
});

comment-form.template.hbs

<form {{action "submitComment" on="submit"}}>
  <label>Comment:</label>
  {{textarea value=comment}}
 
  <input type="submit" value="Submit" />
</form>

twiddle.json

{
  "version": "0.5.3",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.3.1/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.3.3/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember-template-compiler.js"
  }
}