EventedError

components.child-component.js

import Ember from 'ember';
import ParentComponent from 'twiddle/components/parent-component';
const Child = ParentComponent.extend(Ember.Evented, {
  onOpen: function() { alert('success'); }.on('open'),
  actions: {
    open() {
      this.toggleProperty('open'); 
    }
  }
});

export default Child;

components.parent-component.js

import Ember from 'ember';

export default Ember.Component.extend(Ember.Evented, {
  open: false,
  
  _triggerOnOpen() {
    this.trigger('open');
  },
  onOpenChange: function() {
    Ember.run.once(this, this._triggerOnOpen);
  }.observes('open')
});

templates.application.hbs

{{outlet}}
{{child-component}}

templates.components.child-component.hbs

<button {{action 'open'}}>Toggle Open</button>

twiddle.json

{
  "version": "0.10.7",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.10.0",
    "ember-data": "2.10.0",
    "ember-template-compiler": "2.10.0",
    "ember-testing": "2.10.0"
  },
  "addons": {}
}