New Twiddle

components.my-component.js

import Component from '@ember/component';
import { computed } from '@ember/object';

export default Component.extend({
  setCalls: [], // mea culpa!
  
  prop1: computed({
    get() {
      return 'Initial Prop1 Value';
    },
    set(key, value) {
      this.setCalls.pushObject(`prop1 -> ${value}`);
      console.log(new Error().stack);
      return value;
    }
  }),
  
  prop2: computed({
    get() {
      return 'Initial Prop2 Value';
    },
    set(key, value) {
      this.setCalls.pushObject(`prop2 -> ${value}`);
      return value;
    }
  })
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  prop1: 'value1',
  prop2: 'value2'
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<button onclick={{action (mut prop1) (concat prop1 ' x')}}>Set prop1</button>
<br>
<button onclick={{action (mut prop2) (concat prop2 ' x')}}>Set prop2</button>
<br>
{{my-component prop1=prop1 prop2=prop2}}
<br>
<br>

templates.components.my-component.hbs

prop1: {{prop1}}<br>
prop2: {{prop2}}<br>
<br>
set calls:<br>
{{#each setCalls as |setCall|}}
	{{setCall}}<br>
{{/each}}

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"
  }
}