New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  theValue: 'the Text Value',
  actions:{
    getText(arg){
      return arg+'_yay'
    }
  }
});

templates.application.hbs

<h1>Text action</h1>
<br>
<br>
{{use-text text= (get getText theValue)}}
<br>
<br>

templates.components.use-text.hbs

<p>Before</p>
{{text}}
<p>After</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"
  }
}