LibWeb: Implement Node.getRootNode

Userland/Libraries/LibWeb/DOM/Node.cpp

@@ -890,4 +890,14 @@ bool Node::in_a_document_tree() const
     return root().is_document();
 }
 
+// https://dom.spec.whatwg.org/#dom-node-getrootnode
+NonnullRefPtr<Node> Node::get_root_node(GetRootNodeOptions const& options)
+{
+    // The getRootNode(options) method steps are to return this’s shadow-including root if options["composed"] is true; otherwise this’s root.
+    if (options.composed)
+        return shadow_including_root();
+
+    return root();
+}
+
 }

Userland/Libraries/LibWeb/DOM/Node.h

@@ -35,6 +35,10 @@ enum class NodeType : u16 {
     NOTATION_NODE = 12
 };
 
+struct GetRootNodeOptions {
+    bool composed { false };
+};
+
 class Node
     : public TreeNode<Node>
     , public EventTarget
@@ -195,6 +199,8 @@ public:
     bool is_same_node(Node const*) const;
     bool is_equal_node(Node const*) const;
 
+    NonnullRefPtr<Node> get_root_node(GetRootNodeOptions const& options = {});
+
 protected:
     Node(Document&, NodeType);
 

Userland/Libraries/LibWeb/DOM/Node.idl

@@ -13,6 +13,7 @@ interface Node : EventTarget {
     readonly attribute Element? parentElement;
     readonly attribute boolean isConnected;
     readonly attribute Document? ownerDocument;
+    Node getRootNode(optional GetRootNodeOptions options = {});
 
     // FIXME: [LegacyNullToEmptyString] is not allowed on nullable types as per the Web IDL spec.
     //        However, we only apply it to setters, so this works as a stop gap.
@@ -50,3 +51,7 @@ interface Node : EventTarget {
     const unsigned short DOCUMENT_POSITION_CONTAINED_BY = 16;
     const unsigned short DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC = 32;
 };
+
+dictionary GetRootNodeOptions {
+    boolean composed = false;
+};