polyfill-service/polyfills/Element/prototype/after/polyfill.js

A polyfill combinator

Document.prototype.after = Element.prototype.after = function after() {
	if (this.parentNode) {
		var args = Array.prototype.slice.call(arguments),
				viableNextSibling = this.nextSibling,
				idx = viableNextSibling ? args.indexOf(viableNextSibling) : -1;

		while (idx !== -1) {
			viableNextSibling = viableNextSibling.nextSibling;
			if (!viableNextSibling) {
				break;
			}
			idx = args.indexOf(viableNextSibling);
		}
		
		this.parentNode.insertBefore(_mutation(arguments), viableNextSibling);
	}
};

// Not all UAs support the Text constructor.  Polyfill on the Text constructor only where it exists
// TODO: Add a polyfill for the Text constructor, and make it a dependency of this polyfill.
if ("Text" in this) {
	Text.prototype.after = Element.prototype.after;
}