New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  items: [1, 2, 3],
  
  remove() {
    this.items.removeAt(0);
  },
  
  reset() {
    this.set('items', [1, 2, 3]);
  }
});

templates.application.hbs

<button onclick={{action remove}}>Remove</button>
<button onclick={{action reset}}>Reset</button>

{{#each items key='@index' as |item|}}
	{{item}}
{{/each}}

twiddle.json

{
  "version": "0.14.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "2.18.2",
    "ember-template-compiler": "2.18.2",
    "ember-testing": "2.18.2"
  },
  "addons": {
    "ember-data": "2.18.2"
  }
}