New Twiddle

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  init() {
    this._super();
    this.set('bar', { foo: 'stuff' });
    this.set('keys', Object.keys(Ember.get(this, 'bar')));
  },
  
  actions: {
    foo() {
      this.set('keys', Object.keys(Ember.get(this, 'bar')));
      this.setProperties({ 'bar.foo': undefined });
    }
  }
});

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>
{{my-component}}
<br>
<br>

templates.components.my-component.hbs

<p>Current Value: {{bar.foo}}</p>
<p>Random Value: {{bar.random}}</p>
<p>Keys: {{keys}}</p>

<button {{action 'foo'}}>Click Me</button>

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": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}