wrap an element pure javascript
by Simplybj
HTML
<ul class="wrap_me">
<li class="li">asdf</li>
</ul>
JavaScript
// element that will be wrapped
var el = document.querySelector('div.wrap_me');
// create wrapper container
var wrapper = document.createElement('div');
// insert wrapper before el in the DOM tree
el.parentNode.insertBefore(wrapper, el);
// move el into wrapper
wrapper.appendChild(el);