JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://code.jquery.com/qunit/qunit-1.12.0.css">
<script src="http://code.jquery.com/qunit/qunit-1.12.0.js"></script>
<script src="http://sinonjs.org/releases/sinon-1.7.3.js"></script>
<script src="http://sinonjs.org/releases/sinon-qunit-1.0.0.js"></script>
<div id="qunit"></div>
<div id="qunit-fixture"></div>

JavaScript

test("should animate element over 500ms", function () {
    var el = jQuery("<div></div>");
    el.appendTo(document.body);
    ok(el.css('display').indexOf("block") > -1);
    el.fadeOut();
    this.clock.tick(510);
    ok(el.css('display').indexOf("none") > -1);
  
});