Fix AOS detection in MutationObserver

src/js/libs/observer.js

@@ -1,5 +1,25 @@
 let callback = () => {};
 
+function containsAOSNode(nodes) {
+  let i, currentNode, result;
+
+  for (i = 0; i < nodes.length; i += 1) {
+    currentNode = nodes[i];
+
+    if (currentNode.dataset && currentNode.dataset.aos) {
+      return true;
+    }
+
+    result = currentNode.children && containsAOSNode(currentNode.children);
+
+    if (result) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
 function ready(selector, fn) {
   const doc = window.document;
   const MutationObserver =
@@ -23,13 +43,10 @@ function check(mutations) {
   mutations.forEach(mutation => {
     const addedNodes = Array.prototype.slice.call(mutation.addedNodes);
     const removedNodes = Array.prototype.slice.call(mutation.removedNodes);
+    const allNodes = addedNodes.concat(removedNodes);
 
-    const anyAOSElementAdded = addedNodes
-      .concat(removedNodes)
-      .filter(el => el.hasAttribute && el.hasAttribute('data-aos')).length;
-
-    if (anyAOSElementAdded) {
-      callback();
+    if (containsAOSNode(allNodes)) {
+      return callback();
     }
   });
 }