LibWeb: Return actual callback object from NodeIterator::filter

Author: https://github.com/Lubrsi
Commit: 95949ba8f2
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3685
Reviewed-by: https://github.com/gmta ✅

Libraries/LibWeb/DOM/NodeIterator.cpp

@@ -136,6 +136,15 @@ JS::ThrowCompletionOr<GC::Ptr<Node>> NodeIterator::traverse(Direction direction)
     return candidate;
 }
 
+// https://dom.spec.whatwg.org/#concept-traversal-filter
+JS::Object* NodeIterator::filter() const
+{
+    if (!m_filter)
+        return nullptr;
+
+    return m_filter->callback().callback;
+}
+
 // https://dom.spec.whatwg.org/#concept-node-filter
 JS::ThrowCompletionOr<NodeFilter::Result> NodeIterator::filter(Node& node)
 {