Merge pull request #715 from HugoDF/patch-4

IE11 template polyfill issue leads to false warnings

dist/alpine-ie11.js

@@ -1276,7 +1276,28 @@
   })(EventListenerInterceptor);
 
   // For the IE11 build.
-  SVGElement.prototype.contains = SVGElement.prototype.contains || HTMLElement.prototype.contains;
+  SVGElement.prototype.contains = SVGElement.prototype.contains || HTMLElement.prototype.contains // .childElementCount polyfill
+  // from https://developer.mozilla.org/en-US/docs/Web/API/ParentNode/childElementCount#Polyfill_for_IE8_IE9_Safari
+  ;
+
+  (function (constructor) {
+    if (constructor && constructor.prototype && constructor.prototype.childElementCount == null) {
+      Object.defineProperty(constructor.prototype, 'childElementCount', {
+        get: function get() {
+          var i = 0,
+              count = 0,
+              node,
+              nodes = this.childNodes;
+
+          while (node = nodes[i++]) {
+            if (node.nodeType === 1) count++;
+          }
+
+          return count;
+        }
+      });
+    }
+  })(window.Node || window.Element);
 
   var check = function (it) {
     return it && it.Math == Math && it;

src/polyfills.js

@@ -9,3 +9,21 @@ import "events-polyfill/src/constructors/CustomEvent"
 import "events-polyfill/src/ListenerOptions"
 
 SVGElement.prototype.contains = SVGElement.prototype.contains || HTMLElement.prototype.contains
+
+// .childElementCount polyfill
+// from https://developer.mozilla.org/en-US/docs/Web/API/ParentNode/childElementCount#Polyfill_for_IE8_IE9_Safari
+;(function(constructor) {
+    if (constructor &&
+        constructor.prototype &&
+        constructor.prototype.childElementCount == null) {
+        Object.defineProperty(constructor.prototype, 'childElementCount', {
+            get: function() {
+                var i = 0, count = 0, node, nodes = this.childNodes;
+                while (node = nodes[i++]) {
+                    if (node.nodeType === 1) count++;
+                }
+                return count;
+            }
+        });
+    }
+})(window.Node || window.Element);