New Twiddle

components.my-component.js

import Ember from 'ember';
import { schedule } from '@ember/runloop';
import { scheduleTask, runDisposables } from 'ember-lifeline';

export default Ember.Component.extend({
  didInsertElement() {
    schedule('render', () => {
      if (this.get('isDestroying') || this.get('isDestroyed')) {
        alert('destroyed object');  
      }
    });
    
    this._super(...arguments);
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  showComponent: false,
  
  actions: {
   	toggleDisplay() {
      this.toggleProperty('showComponent'); 
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
<a {{action 'toggleDisplay' on="mouseEnter"}} {{action 'toggleDisplay' on="mouseOut"}}>Hello World</a>

{{#if showComponent}}
	{{my-component}}
{{/if}}
<br>
<br>

templates.components.my-component.hbs

{{yield}}
hello

twiddle.json

{
  "version": "0.15.0",
  "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": "3.2.0",
    "ember-lifeline": "3.0.4"
  }
}