JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://code.jquery.com/qunit/qunit-1.11.0.js"></script>
<link rel="stylesheet" href="http://code.jquery.com/qunit/qunit-1.11.0.css">
<script src="http://sinonjs.org/releases/sinon-1.6.0.js"></script>
Bug in either Sinon.JS or jQuery.<br>
PASSES with jQuery 1.9.1<br>
FAILS with jQuery 2.0.0

<div id="qunit"></div>
<div id="qunit-fixture"></div>

JavaScript

test('$.ajax', function() {
    this.server = sinon.fakeServer.create();
    this.server.respondWith('ok');
    $.ajax('/foo').success(function() { ok(1); });
    this.server.respond();
});