Remove jQuery from alert.js and add .alert only if jQuery is available

js/src/dom/data.js

@@ -10,7 +10,7 @@ const mapData = (() => {
   return {
     set(element, key, data) {
       let id
-      if (element.key === undefined) {
+      if (typeof element.key === 'undefined') {
         element.key = {
           key,
           id
@@ -20,14 +20,14 @@ const mapData = (() => {
       storeData[id] = data
     },
     get(element, key) {
-      if (element.key === undefined || element.key !== key) {
+      if (typeof element.key === 'undefined' || element.key !== key) {
         return null
       }
       const keyProperties = element.key
       return storeData[keyProperties.id]
     },
     delete(element, key) {
-      if (element.key === undefined || element.key !== key) {
+      if (typeof element.key === 'undefined' || element.key !== key) {
         return
       }
       const keyProperties = element.key

js/src/dom/eventHandler.js

@@ -19,7 +19,8 @@ if (typeof window.CustomEvent !== 'function') {
   window.CustomEvent = (event, params) => {
     params = params || {
       bubbles: false,
-      cancelable: false
+      cancelable: false,
+      detail: null
     }
     const evt = document.createEvent('CustomEvent')
     evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail)
@@ -101,6 +102,8 @@ function bootstrapDelegationHandler(selector, fn) {
         }
       }
     }
+    // To please ESLint
+    return null
   }
 }
 

js/src/dom/selectorEngine.js

@@ -16,9 +16,8 @@ if (!Element.prototype.matches) {
 }
 
 // closest polyfill (see: https://mzl.la/2vXggaI)
-let fnClosest = null
 if (!Element.prototype.closest) {
-  fnClosest = (element, selector) => {
+  Element.prototype.closest = (element, selector) => {
     let ancestor = element
     if (!document.documentElement.contains(element)) {
       return null
@@ -34,12 +33,10 @@ if (!Element.prototype.closest) {
 
     return null
   }
-} else {
-  fnClosest = (element, selector) => {
-    return element.closest(selector)
-  }
 }
 
+const fnClosest = Element.prototype.closest
+
 const SelectorEngine = {
   matches(element, selector) {
     return fnMatches.call(element, selector)
@@ -59,7 +56,7 @@ const SelectorEngine = {
   },
 
   closest(element, selector) {
-    return fnClosest(element, selector)
+    return fnClosest.call(element, selector)
   }
 }