Nested Stateful Helpers

controllers.application.js

import Ember from 'ember';

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

helpers.a.js

import Ember from 'ember';

export default Ember.Helper.extend({
  compute() {
    return 'a';
  }
});

helpers.b.js

import Ember from 'ember';

export default Ember.Helper.extend({
  compute() {
    // must change to lookupFactory('helper:a').create() for ember 2.10
    let a = this.container.lookup('helper:a');
    return 'b ' + a.compute();
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{a}}
{{b}}
<br>
<br>

twiddle.json

{
  "version": "0.11.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.10.2",
    "ember-data": "2.11.0",
    "ember-template-compiler": "2.10.2",
    "ember-testing": "2.10.2"
  },
  "addons": {}
}