New Twiddle

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  test: null,
  
  
  didReceiveAttrs() {
    console.log("DID recevie attrs: ", this.get('test'));
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  test: Ember.Object.create(),
  
  a() {
      console.log('set path');
      this.set('test.wojtek', 5);
    },
 
  actions: {
    
    a() {
      console.log('set path');
      this.set('test.wojtek', 5);
    },
    b() {
      console.log('set attribut');
      this.set('test', Ember.Object.create());
    },
  }
  
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{my-component test=test}}

<button {{action a}}>a</button>

<button {{action b}}>b</button>

templates.components.my-component.hbs

{{yield}}

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"
  }
}