JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://codemirror.net/2/lib/codemirror.css">
<script src="http://codemirror.net/2/lib/codemirror.js"></script>
<script src="http://codemirror.net/2/lib/util/formatting.js"></script>
<script src="http://codemirror.net/2/mode/css/css.js"></script>
<script src="http://codemirror.net/2/mode/xml/xml.js"></script>
<script src="http://codemirror.net/2/mode/htmlmixed/htmlmixed.js"></script>
<script src="http://codemirror.net/2/mode/javascript/javascript.js"></script>
<link rel="stylesheet" href="http://codemirror.net/2/doc/docs.css">
<input type="button" onclick="autoFormatSelection()" value="autoFormatSelection">
<input type="button" onclick="commentSelection(true)" value="commentSelection">

    <form><textarea id="code" name="code"><script> function (s,e){ for(var i=0; i < 1; i++) test("test();a=1");} </script>
<script>
function test(c){  for (var i = 0; i < 10; i++){	          process("a.b();c = null;", 300);}
}
</script>
<table><tr><td>test 1</td></tr><tr><td>test 2</td></tr></table>
<script> function test() { return 1;} </script>
<style> .test { font-size: medium; font-family: monospace; }
</style></textarea></form>

CSS

.CodeMirror {
        border: 1px solid #eee;
      }
      td {
        padding-right: 20px;
      }

JavaScript

var editor = CodeMirror.fromTextArea(document.getElementById("code"), {
        lineNumbers: true,
        mode: "htmlmixed",
        extraKeys:{"Shift-Tab":autoFormatSelection}
      });

      
      function getSelectedRange() {
        return { from: editor.getCursor(true), to: editor.getCursor(false) };
      }
      
      function autoFormatSelection() {
        var range = getSelectedRange();
        editor.autoFormatRange(range.from, range.to);
      }
      
      function commentSelection(isComment) {
        var range = getSelectedRange();
        editor.commentRange(isComment, range.from, range.to);
      }