fix window.CustomEvent

customEvent.js

/**
 * CustomEvent polyfill
 * https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent#Polyfill
 */
(function () {
    try {
        // a : While a window.CustomEvent object exists, it cannot be called as a constructor.
        // b : There is no window.CustomEvent object
        new window.CustomEvent('T');
    } catch (e) {
        var CustomEvent = function (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;
    }
})();