New Twiddle

components.bar-comp.js

import Ember from 'ember';

export default Ember.Component.extend({
  
});

components.baz-com.js

import Ember from 'ember';

export default Ember.Component.extend({

});

components.doo-doo.js

import Ember from 'ember';
import { tryInvoke } from '@ember/utils';

export default Ember.Component.extend({
  actions: {
    makePoopy() {
    	tryInvoke(this, 'a', ['I make a dookie!']);
    },    
  },
});

components.foo-comp.js

import Ember from 'ember';

export default Ember.Component.extend({
  actions: {
    a(message) {
      alert(message)
    }
  }
});

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>

{{foo-comp}}

<br>
<br>

templates.components.bar-comp.hbs

{{baz-com a=a}}

templates.components.baz-com.hbs

{{doo-doo a=a}}

templates.components.doo-doo.hbs

<button {{action "makePoopy"}}>Doo doo</button>

templates.components.foo-comp.hbs

{{bar-comp a=(action "a")}}

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": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}