From 288379aa7dd8da49eed42dec9eb5ba75f8ad194b Mon Sep 17 00:00:00 2001
From: Karl Seguin <k@openmymind.io>
Date: Thu, 16 Oct 2025 19:08:33 +0800
Subject: [PATCH] support the composed option of getRootNode()

---
 src/browser/dom/node.zig | 28 ++++++++++++++++++++--------
 src/tests/dom/node.html  | 21 +++++++++++++++++++++
 2 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/src/browser/dom/node.zig b/src/browser/dom/node.zig
index 71b88e0e..b84ae9d3 100644
--- a/src/browser/dom/node.zig
+++ b/src/browser/dom/node.zig
@@ -360,18 +360,30 @@ pub const Node = struct {
         node: Union,
     };
     pub fn _getRootNode(self: *parser.Node, options: ?struct { composed: bool = false }, page: *Page) !GetRootNodeResult {
-        if (options) |options_| if (options_.composed) {
-            log.warn(.web_api, "not implemented", .{ .feature = "getRootNode composed" });
-        };
+        const composed = if (options) |opts| opts.composed else false;
 
-        const root = parser.nodeGetRootNode(self);
-        if (page.getNodeState(root)) |state| {
-            if (state.shadow_root) |sr| {
-                return .{ .shadow_root = sr };
+        var current_root = parser.nodeGetRootNode(self);
+
+        while (true) {
+            const node_type = parser.nodeType(current_root);
+
+            if (node_type == .document_fragment) {
+                if (parser.documentFragmentGetHost(@ptrCast(current_root))) |host| {
+                    if (page.getNodeState(host)) |state| {
+                        if (state.shadow_root) |sr| {
+                            if (!composed) {
+                                return .{ .shadow_root = sr };
+                            }
+                            current_root = parser.nodeGetRootNode(@ptrCast(sr.host));
+                            continue;
+                        }
+                    }
+                }
             }
+            break;
         }
 
-        return .{ .node = try Node.toInterface(root) };
+        return .{ .node = try Node.toInterface(current_root) };
     }
 
     pub fn _hasChildNodes(self: *parser.Node) bool {
diff --git a/src/tests/dom/node.html b/src/tests/dom/node.html
index cdea68d6..ae9b8a3e 100644
--- a/src/tests/dom/node.html
+++ b/src/tests/dom/node.html
@@ -7,6 +7,7 @@
     <p id="para"> And</p>
     <!--comment-->
   </div>
+  <div id="rootNodeComposed"></div>
 </body>
 
 <script src="../testing.js"></script>
@@ -36,6 +37,26 @@ let first_child = content.firstChild.nextSibling; // nextSibling because of line
   testing.expectEqual('HTMLDocument', content.getRootNode().__proto__.constructor.name);
 </script>
 
+<script id=getRootNodeComposed>
+  const testContainer = $('#rootNodeComposed');
+  const shadowHost = document.createElement('div');
+  testContainer.appendChild(shadowHost);
+  const shadowRoot = shadowHost.attachShadow({ mode: 'open' });
+  const shadowChild = document.createElement('span');
+  shadowRoot.appendChild(shadowChild);
+
+  testing.expectEqual('ShadowRoot', shadowChild.getRootNode().__proto__.constructor.name);
+  testing.expectEqual('ShadowRoot', shadowChild.getRootNode({ composed: false }).__proto__.constructor.name);
+  testing.expectEqual('HTMLDocument', shadowChild.getRootNode({ composed: true }).__proto__.constructor.name);
+  testing.expectEqual('HTMLDocument', shadowHost.getRootNode().__proto__.constructor.name);
+
+  const disconnected = document.createElement('div');
+  const disconnectedChild = document.createElement('span');
+  disconnected.appendChild(disconnectedChild);
+  testing.expectEqual('HTMLDivElement', disconnectedChild.getRootNode().__proto__.constructor.name);
+  testing.expectEqual('HTMLDivElement', disconnectedChild.getRootNode({ composed: true }).__proto__.constructor.name);
+</script>
+
 <script id=firstChild>
   let body_first_child = document.body.firstChild;
   testing.expectEqual('div', body_first_child.localName);