New Twiddle

components.attributes-checker.js

import Ember from 'ember';

export default Ember.Component.extend({
  test: 4,
  click() {
		console.log("CLICKED");
    this.set('test', Math.random());
  },
  didReceiveAttrs() {
   console.log("DID", this.get("test")); 
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',

    	update() {
      console.log("ACTION CONTROLLER CALLED");
  		this.set('test', Math.random() + '-outside')
      
      },

        
  actions: {
  	update() {
      console.log("ACTION CONTROLLER CALLED");
  		this.set('test', Math.random() + '-outside');
	
}
	}
});

templates.application.hbs

{{attributes-checker
test=appName
}}
<button action={{action 'update'}}>update</button>

templates.components.attributes-checker.hbs

|{{test}}|

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"
  }
}