JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://code.jquery.com/jquery-2.1.1.js"></script>
<script src="http://lrdv.eu/embercdn/handlebars-v1.3.0.js"></script>
<script src="http://builds.emberjs.com/release/ember.js"></script>
<script src="http://code.jquery.com/qunit/qunit-1.15.0.js"></script>
<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css" rel="stylesheet">
 <script src="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
<script src="http://lrdv.eu/embercdn/bootbox.js"></script>
<link rel="stylesheet" href="//code.jquery.com/qunit/qunit-1.14.0.css">

<script type="text/x-handlebars" data-template-name="application">
    <h1>Test app</h1>
    {{outlet}}
</script>
<script type="text/x-handlebars" data-template-name="index">
    <h3>The index file</h3>
    <p>Dit is een zin <a id="link" href="#" {{action 'save' target="view"}}>Klik hier om op te slaan</a></p>
    <div id="block" style="height:100px;width:100px;background-color:red"></div>
</script>
  <div id="qunit"></div>
  <div id="ember_content"></div>
    
  <div id="qunit-fixture"></div>

JavaScript

window.App = Ember.Application.create();
App.rootElement = '#ember_content';
App.setupForTesting();
App.injectTestHelpers();

App.IndexView = Ember.View.extend({
    actions: {
        save: function(){
            
            var self = this;
            bootbox.confirm('Make it async', function(){ 
                 self.$().find('#block').remove();
            });
            
            /** this works
            Ember.run.later(function(){
                 self.$().find('#block').remove();
            },1000);
            */
        }
    }
});

test('Test ', function(){
  visit('/');
  andThen(function() {
      equal(find('#block').length,1, 'There should be a block on the page');
  });
  click("#link");
  andThen(function() {
      equal(find('#block').length,0, 'There should be no block on the page');
  });
});