From 36d267ca40b5c5a54ef165ee1b8233e5f0ac85c7 Mon Sep 17 00:00:00 2001
From: Karl Seguin <k@openmymind.io>
Date: Mon, 9 Feb 2026 17:38:11 +0800
Subject: [PATCH] Improve Selection compatibility

collapse-30.html WPT test from from 2753/5133 to 5133/5133.

-Return dom_exception from setPosition
-Verify node containment in document
---
 src/browser/webapi/Node.zig      | 7 +++++++
 src/browser/webapi/Selection.zig | 7 ++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/browser/webapi/Node.zig b/src/browser/webapi/Node.zig
index a21fa568..bcf0ac1b 100644
--- a/src/browser/webapi/Node.zig
+++ b/src/browser/webapi/Node.zig
@@ -457,6 +457,13 @@ pub fn ownerDocument(self: *const Node, page: *const Page) ?*Document {
     return page.document;
 }
 
+pub fn isSameDocumentAs(self: *const Node, other: *const Node, page: *const Page) bool {
+    // Get the root document for each node
+    const self_doc = if (self._type == .document) self._type.document else self.ownerDocument(page);
+    const other_doc = if (other._type == .document) other._type.document else other.ownerDocument(page);
+    return self_doc == other_doc;
+}
+
 pub fn hasChildNodes(self: *const Node) bool {
     return self.firstChild() != null;
 }
diff --git a/src/browser/webapi/Selection.zig b/src/browser/webapi/Selection.zig
index 69054b17..a1613138 100644
--- a/src/browser/webapi/Selection.zig
+++ b/src/browser/webapi/Selection.zig
@@ -370,6 +370,11 @@ pub fn collapse(self: *Selection, _node: ?*Node, _offset: ?u32, page: *Page) !vo
         return error.IndexSizeError;
     }
 
+    // If the node is not contained in the document, do not change the selection
+    if (!page.document.asNode().contains(node)) {
+        return;
+    }
+
     const range = try Range.init(page);
     try range.setStart(node, offset);
     try range.setEnd(node, offset);
@@ -416,7 +421,7 @@ pub const JsApi = struct {
     pub const removeRange = bridge.function(Selection.removeRange, .{ .dom_exception = true });
     pub const selectAllChildren = bridge.function(Selection.selectAllChildren, .{});
     pub const setBaseAndExtent = bridge.function(Selection.setBaseAndExtent, .{ .dom_exception = true });
-    pub const setPosition = bridge.function(Selection.collapse, .{});
+    pub const setPosition = bridge.function(Selection.collapse, .{ .dom_exception = true });
     pub const toString = bridge.function(Selection.toString, .{});
 };