JSFiddle - React, Tailwind, and code Playground
HTML
<script src="http://getfirebug.com/firebug-lite-debug.js"></script>
<div class="foo.bar"></div>
JavaScript
console.log( $('[class="foo.bar"]') ); // Works, but don't use periods in classes
console.log( $('[class=foo.bar]') ); // Unrecognized expression, throws exception