New Twiddle

components.x-list.js

import Ember from 'ember';
import titleComponent from 'app/components/x-list/list-item'

export default Ember.Component.extend({
  titleComponent: titleComponent,
});

components.x-list.list-item.js

import Ember from 'ember';

export default Ember.Component.extend({
});

controllers.application.js

import Ember from 'ember';

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

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>
{{#x-list as |list|}}
  {{#list.item}}
    hello
  {{/list.item}}
{{/x-list}}

templates.components.x-list.hbs

{{yield (hash item=titleComponent)}}

templates.components.x-list.list-item.hbs

item - {{yield}}

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1"
  }
}