JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://github.com/jshint/jshint/raw/master/jshint.js"></script>

JavaScript

var code = "var test; for (var i in test) { if (test.hasOwnProperty(i)) { alert('.'); } }";

var result = JSHINT(code, {sub:true});

alert(result);