JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://view.jqueryui.com/selectmenu/ui/jquery.ui.core.js"></script>
<script src="http://view.jqueryui.com/selectmenu/ui/jquery.ui.widget.js"></script>
<script src="http://view.jqueryui.com/selectmenu/ui/jquery.ui.position.js"></script>
<script src="http://view.jqueryui.com/selectmenu/ui/jquery.ui.menu.js"></script>
<script src="http://view.jqueryui.com/selectmenu/ui/jquery.ui.selectmenu.js"></script>
<link rel="stylesheet" href="http://view.jqueryui.com/selectmenu/themes/base/jquery.ui.all.css">
<link rel="stylesheet" href="http://view.jqueryui.com/selectmenu/demos/demos.css">
<select id="testcase">
    <option>Test 1</option>
    <option>Test 2</option>
    <option>Test 3</option>
</select>

CSS

#testcase{
    width: 150px;
}

JavaScript

$("#testcase").selectmenu();

$("<option selected>newOption</option>").prependTo("#testcase");

$("#testcase").selectmenu("refresh");