Add CustomEvent polyfill and a working preventDefault for IE

js/src/alert.js

@@ -85,7 +85,8 @@ class Alert {
     let parent     = false
 
     if (selector) {
-      parent = document.querySelector(selector)
+      const tmpSelected = SelectorEngine.find(selector)
+      parent = tmpSelected[0]
     }
 
     if (!parent) {

js/src/dom/eventHandler.js

@@ -5,6 +5,58 @@
  * --------------------------------------------------------------------------
  */
 
+// defaultPrevented is broken in IE.
+// https://connect.microsoft.com/IE/feedback/details/790389/event-defaultprevented-returns-false-after-preventdefault-was-called
+const workingDefaultPrevented = (() => {
+  const e = document.createEvent('CustomEvent')
+  e.initEvent('Bootstrap', true, true)
+  e.preventDefault()
+  return e.defaultPrevented
+})()
+
+// CustomEvent polyfill for IE (see: https://mzl.la/2v76Zvn)
+if (typeof window.CustomEvent !== 'function') {
+  window.CustomEvent = (event, params) => {
+    params = params || {
+      bubbles: false,
+      cancelable: false
+    }
+    const evt = document.createEvent('CustomEvent')
+    evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail)
+    if (!workingDefaultPrevented) {
+      const origPreventDefault = Event.prototype.preventDefault
+      evt.preventDefault = () => {
+        if (!evt.cancelable) {
+          return
+        }
+
+        origPreventDefault.call(evt)
+        Object.defineProperty(evt, 'defaultPrevented', {
+          get() {
+            return true
+          },
+          configurable: true
+        })
+      }
+    }
+    return evt
+  }
+
+  window.CustomEvent.prototype = window.Event.prototype
+}
+
+// Event constructor shim
+if (!window.Event || typeof window.Event !== 'function') {
+  const origEvent = window.Event
+  window.Event = (inType, params) => {
+    params = params || {}
+    const e = document.createEvent('Event')
+    e.initEvent(inType, Boolean(params.bubbles), Boolean(params.cancelable))
+    return e
+  }
+  window.Event.prototype = origEvent.prototype
+}
+
 const EventHandler = {
   on(element, event, handler) {
     if (typeof event !== 'string' || typeof element === 'undefined') {
@@ -31,6 +83,9 @@ const EventHandler = {
       bubbles: true,
       cancelable: true
     })
+
+    // Add a function 'isDefaultPrevented'
+    eventToDispatch.isDefaultPrevented = () => eventToDispatch.defaultPrevented
     element.dispatchEvent(eventToDispatch)
 
     return eventToDispatch