Element.closest(selector) polyfill

element-closest-polyfill.js

/**
 * Element.closest(selector) polyfill
 *
 * https://developer.mozilla.org/en-US/docs/Web/API/Element/closest#Polyfill
 */
(function(){
    if (!Element.prototype.matches) {
        Element.prototype.matches = Element.prototype.msMatchesSelector || Element.prototype.webkitMatchesSelector;
    }
    if (!Element.prototype.closest) {
        Element.prototype.closest = function(s) {
            var el = this;
            do {
                if (el.matches(s)) return el;
                el = el.parentElement || el.parentNode;
            } while (el !== null && el.nodeType === 1);
            return null;
        };
    }
})();