New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  lineItems: [],
  init() {
    this._super(...arguments);
    this.lineItems.push(11);
    this.lineItems.push(22);
    this.lineItems.push(33);
  },
  actions: {
    input: function(index,e) {
      console.log(e.target.value);
      this.set('lineItems[' + index + ']', e.target.value);
      this.set('lineItems', Ember.copy(this.lineItems));
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<ul>
{{#each lineItems as |lineItem index|}}
<li>{{lineItem}} {{input value=lineItem input=(action 'input' index)}}</li>
{{/each}}
</ul>
<br>
<br>

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}