From d00adabc3c13f18ca46e9c8ab329551fdc3fdef3 Mon Sep 17 00:00:00 2001
From: scorpion-26 <dev.scorpion26@gmail.com>
Date: Thu, 3 Oct 2024 23:12:15 +0200
Subject: [PATCH] LibWeb: Preserve order of HTMLCollection property names

The supported property names should be ordered in "tree order", though
m_cached_name_to_element_mappings doesn't preserve this ordering, which
breaks Object.getOwnPropertyNames.

Fixes at least the following WPT tests:
 - https://wpt.live/dom/nodes/Element-children.html
 - https://wpt.live/dom/collections/HTMLCollection-live-mutations.window.html
 - https://wpt.live/dom/collections/HTMLCollection-supported-property-names.html
---
 .../HTMLCollection-property-names-iteration-order.txt  |  1 +
 .../HTMLCollection-property-names-iteration-order.html | 10 ++++++++++
 Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp       |  2 +-
 Userland/Libraries/LibWeb/DOM/HTMLCollection.h         |  2 +-
 4 files changed, 13 insertions(+), 2 deletions(-)
 create mode 100644 Tests/LibWeb/Text/expected/DOM/HTMLCollection-property-names-iteration-order.txt
 create mode 100644 Tests/LibWeb/Text/input/DOM/HTMLCollection-property-names-iteration-order.html

diff --git a/Tests/LibWeb/Text/expected/DOM/HTMLCollection-property-names-iteration-order.txt b/Tests/LibWeb/Text/expected/DOM/HTMLCollection-property-names-iteration-order.txt
new file mode 100644
index 00000000000..dd3ca6e56a7
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/DOM/HTMLCollection-property-names-iteration-order.txt
@@ -0,0 +1 @@
+0,1,2,foo,bar,baz
diff --git a/Tests/LibWeb/Text/input/DOM/HTMLCollection-property-names-iteration-order.html b/Tests/LibWeb/Text/input/DOM/HTMLCollection-property-names-iteration-order.html
new file mode 100644
index 00000000000..7d9205c3b94
--- /dev/null
+++ b/Tests/LibWeb/Text/input/DOM/HTMLCollection-property-names-iteration-order.html
@@ -0,0 +1,10 @@
+<a name="foo"></a>
+<a name="bar"></a>
+<a name="baz"></a>
+
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        println(Object.getOwnPropertyNames(document.anchors));
+    });
+</script>
diff --git a/Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp b/Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp
index 021d2b9763f..19a9d2a4c79 100644
--- a/Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp
+++ b/Userland/Libraries/LibWeb/DOM/HTMLCollection.cpp
@@ -57,7 +57,7 @@ void HTMLCollection::update_name_to_element_mappings_if_needed() const
     update_cache_if_needed();
     if (m_cached_name_to_element_mappings)
         return;
-    m_cached_name_to_element_mappings = make<HashMap<FlyString, JS::NonnullGCPtr<Element>>>();
+    m_cached_name_to_element_mappings = make<OrderedHashMap<FlyString, JS::NonnullGCPtr<Element>>>();
     for (auto const& element : m_cached_elements) {
         // 1. If element has an ID which is not in result, append element’s ID to result.
         if (auto const& id = element->id(); id.has_value()) {
diff --git a/Userland/Libraries/LibWeb/DOM/HTMLCollection.h b/Userland/Libraries/LibWeb/DOM/HTMLCollection.h
index 5b08fc43f5c..5ebafa79772 100644
--- a/Userland/Libraries/LibWeb/DOM/HTMLCollection.h
+++ b/Userland/Libraries/LibWeb/DOM/HTMLCollection.h
@@ -61,7 +61,7 @@ private:
 
     mutable u64 m_cached_dom_tree_version { 0 };
     mutable Vector<JS::NonnullGCPtr<Element>> m_cached_elements;
-    mutable OwnPtr<HashMap<FlyString, JS::NonnullGCPtr<Element>>> m_cached_name_to_element_mappings;
+    mutable OwnPtr<OrderedHashMap<FlyString, JS::NonnullGCPtr<Element>>> m_cached_name_to_element_mappings;
 
     JS::NonnullGCPtr<ParentNode> m_root;
     Function<bool(Element const&)> m_filter;