Flipping Checkbox

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName:'Ember Twiddle',
  valueUndefined: undefined,
  valueNull: null,
  valueFalse: false,
  
  value1: Ember.computed('valueUndefined', {
    get: function() {
      return !this.get('valueUndefined');
		},
    set: function(key, value) {
      console.log('In here');
      return value;
    }
	}),
  
  allItemsSelected: false,
  
  isSelected: Ember.computed('allItemsSelected', {
    get: function() {
      return this.get('allItemsSelected'); 
    }
  }).readOnly(),
  
  actions: {
    selectAllItems(value) {
      this.set('allItemsSelected', value);
    }
  }
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>

<p>
Initial is undefined<br />
{{input type='checkbox' checked=value1}} {{value1}} {{valueUndefined}}
</p>

<input type="checkbox"
          id="select-all-profiles"
          class="paginated-view__all-checkbox small-input"
          checked={{isSelected}}
          data-test-all-checkbox
>
{{isSelected}}

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": "0.4.16",
  "EmberENV": {
    "FEATURES": {}
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.9.0",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.1.0/ember-data.js",
    "ember-template-compiler": "2.9.0"
  },
  "options": {
    "enable-testing": false
  }
}