JavaScript polyfills for matches,closest, and forEach.

_polyfills.js

// https://github.com/jonathantneal/closest/blob/master/src/index.js
var ElementPrototype = window.Element.prototype;
if (typeof ElementPrototype.matches !== 'function') {
  ElementPrototype.matches = ElementPrototype.msMatchesSelector || ElementPrototype.mozMatchesSelector || ElementPrototype.webkitMatchesSelector || function matches(selector) {
    var element = this;
    var elements = (element.document || element.ownerDocument).querySelectorAll(selector);
    var index = 0;
    while (elements[index] && elements[index] !== element) {
      ++index;
    }
    return Boolean(elements[index]);
  };
}
if (typeof ElementPrototype.closest !== 'function') {
  ElementPrototype.closest = function closest(selector) {
    var element = this;
    while (element && element.nodeType === 1) {
      if (element.matches(selector)) {
        return element;
      }
      element = element.parentNode;
    }
    return null;
  };
}
// https://gist.github.com/hufyhang/c303ce1b80c7b6f8a73e
if (!Array.prototype.forEach) {
  Array.prototype.forEach = function forEach (callback, thisArg) {
    if (typeof callback !== 'function') {
      throw new TypeError(callback + ' is not a function');
    }
    var array = this;
    thisArg = thisArg || this;
    for (var i = 0, l = array.length; i !== l; ++i) {
      callback.call(thisArg, array[i], i, array);
    }
  };
}
// https://vanillajstoolkit.com/polyfills/nodelistforeach/
if (window.NodeList && !NodeList.prototype.forEach) {
  NodeList.prototype.forEach = function (callback, thisArg) {
    thisArg = thisArg || window;
    for (var i = 0; i < this.length; i++) {
      callback.call(thisArg, this[i], i, this);
    }
  };
}