frequently used polyfills

polyfills.js

// Element.matches()
if (!Element.prototype.matches)
    Element.prototype.matches =
        Element.prototype.msMatchesSelector ||
        Element.prototype.webkitMatchesSelector


// NodeList.forEach()
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)
        }
    }
}

// CustomEvent()
if ( typeof window.CustomEvent === "function" ) return false

function CustomEvent ( event, params ) {
  params = params || { bubbles: false, cancelable: false, detail: undefined }
  var evt = document.createEvent( 'CustomEvent' )
  evt.initCustomEvent( event, params.bubbles, params.cancelable, params.detail )
  return evt
 }

CustomEvent.prototype = window.Event.prototype

window.CustomEvent = CustomEvent