Select demo

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  vehicle: null,
  vehicles: ['Tesla', 'Chrysler', 'Toyota'],
  actions: {
    selectVehicle(vehicle) {
      this.set('vehicle', vehicle);
    }
  }
});

helpers.eq.js

import Ember from 'ember';

export function eq(params) {
  return params[0] === params[1];
}

export default Ember.Helper.helper(eq);

templates.application.hbs

<select onchange={{action "selectVehicle" value="target.value"}}>
<option
 disabled={{if vehicle true false}}
 selected={{if vehicle true false}}>Choose one:</option>
  {{#each vehicles as |vehicleChoice|}}
    <option
      selected={{eq vehicle vehicleChoice}}>{{vehicleChoice}}</option>
  {{/each}}
</select>


<select onchange={{action "selectVehicle" value="target.value"}}>

{{#if vehicle}}
  <option disabled >Choose one:</option>
{{else}}
  <option selected disabled >Choose one:</option>
{{/if}}

  {{#each vehicles as |vehicleChoice|}}
    {{#if (eq vehicle vehicleChoice)}}
      <option selected>{{vehicleChoice}}</option>
    {{else}}
      <option>{{vehicleChoice}}</option>
    {{/if}}
  {{/each}}
</select>

{{#if vehicle}}<p>Selected: {{vehicle}}</p>{{/if}}

tests.helpers.destroy-app.js

import Ember from 'ember';

export default function destroyApp(application) {
  Ember.run(application, 'destroy');
}

tests.helpers.resolver.js

import Resolver from '../../resolver';
import config from '../../config/environment';

const resolver = Resolver.create();

resolver.namespace = {
  modulePrefix: config.modulePrefix,
  podModulePrefix: config.podModulePrefix
};

export default resolver;

tests.helpers.start-app.js

import Ember from 'ember';
import Application from '../../app';
import config from '../../config/environment';

const { run } = Ember;
const assign = Ember.assign || Ember.merge;

export default function startApp(attrs) {
  let application;

  let attributes = assign({rootElement: "#test-root"}, config.APP);
  attributes = assign(attributes, attrs); // use defaults, but you can override;

  run(() => {
    application = Application.create(attributes);
    application.setupForTesting();
    application.injectTestHelpers();
  });

  return application;
}

tests.test-helper.js

import resolver from './helpers/resolver';
import {
  setResolver
} from 'ember-qunit';

setResolver(resolver);

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": {}
}