Possible service replacement

components.child-component.js

import Ember from 'ember';

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

components.parent-component.js

import Ember from 'ember';
import {inject as service} from '@ember/service'

export default Ember.Component.extend({
  alert: service()
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

services.alert.js

import Ember from 'ember';

export default Ember.Service.extend({
  someMethod(txt) {
  	alert(txt)
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{parent-component}}
<br>
<br>

templates.components.child-component.hbs

{{yield}}
child component
<button {{action clickable "child component was clicked"}}>click to show alert</button>

templates.components.parent-component.hbs

{{yield}}
<p>
parent component
<button {{action alert.someMethod "parent component was clicked"}}>click to show alert</button>
</p>
<p>
{{child-component clickable=alert.someMethod}}
</p>

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"
  }
}