Disable ESlint on no-return-assign and temporary for arrow-body-style

js/src/alert.js

@@ -66,7 +66,7 @@ class Alert {
 
     const customEvent = this._triggerCloseEvent(rootElement)
 
-    if (customEvent.defaultPrevented) {
+    if (customEvent === null || customEvent.defaultPrevented) {
       return
     }
 

js/src/dom/selectorEngine.js

@@ -16,8 +16,9 @@ if (!Element.prototype.matches) {
 }
 
 // closest polyfill (see: https://mzl.la/2vXggaI)
+let fnClosest = null
 if (!Element.prototype.closest) {
-  Element.prototype.closest = (element, selector) => {
+  fnClosest = (element, selector) => {
     let ancestor = element
     if (!document.documentElement.contains(element)) {
       return null
@@ -33,10 +34,13 @@ if (!Element.prototype.closest) {
 
     return null
   }
+} else {
+  // eslint-disable-next-line arrow-body-style
+  fnClosest = (element, selector) => {
+    return element.closest(selector)
+  }
 }
 
-const fnClosest = Element.prototype.closest
-
 const SelectorEngine = {
   matches(element, selector) {
     return fnMatches.call(element, selector)
@@ -56,7 +60,7 @@ const SelectorEngine = {
   },
 
   closest(element, selector) {
-    return fnClosest.call(element, selector)
+    return fnClosest(element, selector)
   }
 }