Component Namespacing

components.addon-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  classNames: ['addon-component']
});

controllers.application.js

import Ember from 'ember';

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

styles.app.css

/* SITE STYLES */
body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

/* APP STYLES */
p {
  color: blue;
}

/* ADDON STYLES */
.addon-component p {
  padding: 0 0.5rem;
  color: white;
  background: blue;
}

templates.application.hbs

<p>Paragraph in parent app.</p>

{{addon-component}}

<p>Paragraph in parent app.</p>

{{addon-component}}

templates.components.addon-component.hbs

<p>Paragraph in addon-component.</p>

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"
  }
}