From 0127190dcf7fd0ee27a935cf1f3f5c74b77c0fc9 Mon Sep 17 00:00:00 2001
From: Tim Ledbetter <tim.ledbetter@ladybird.org>
Date: Tue, 23 Jul 2024 13:10:50 +0100
Subject: [PATCH] LibWeb: Perform DOMTokenList token validation in the correct
 order

---
 .../Text/expected/DOM/Element-classList.txt   |  1 +
 .../Text/input/DOM/Element-classList.html     |  6 ++++++
 .../Libraries/LibWeb/DOM/DOMTokenList.cpp     | 19 +++++++++++++++++--
 Userland/Libraries/LibWeb/DOM/DOMTokenList.h  |  2 ++
 4 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/Tests/LibWeb/Text/expected/DOM/Element-classList.txt b/Tests/LibWeb/Text/expected/DOM/Element-classList.txt
index c9b7f958521..de17e2a005a 100644
--- a/Tests/LibWeb/Text/expected/DOM/Element-classList.txt
+++ b/Tests/LibWeb/Text/expected/DOM/Element-classList.txt
@@ -3,3 +3,4 @@ element.classList after setting classList to "a": "a"
 element.classList after setting className to "": ""
 element.classList after setting to className to "a a b c": "a a b c"
 element.classList after setting to className to "   a a b c ": "   a a b c "
+element.classList.replace(" ", "") throws "SyntaxError"
diff --git a/Tests/LibWeb/Text/input/DOM/Element-classList.html b/Tests/LibWeb/Text/input/DOM/Element-classList.html
index 72d7f53c265..3f2243d56b9 100644
--- a/Tests/LibWeb/Text/input/DOM/Element-classList.html
+++ b/Tests/LibWeb/Text/input/DOM/Element-classList.html
@@ -12,6 +12,12 @@
         println(`element.classList after setting to className to "a a b c": "${element.classList.toString()}"`);
         element.className = "   a a b c ";
         println(`element.classList after setting to className to "   a a b c ": "${element.classList.toString()}"`);
+
+        try {
+            element.classList.replace(" ", "");
+        } catch (e) {
+            println(`element.classList.replace(" ", "") throws "${e.name}"`);
+        }
     });
 </script>
 </html>
diff --git a/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp b/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp
index dbbd7b57c2e..fa837c9bb71 100644
--- a/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp
+++ b/Userland/Libraries/LibWeb/DOM/DOMTokenList.cpp
@@ -192,9 +192,12 @@ WebIDL::ExceptionOr<bool> DOMTokenList::toggle(String const& token, Optional<boo
 WebIDL::ExceptionOr<bool> DOMTokenList::replace(String const& token, String const& new_token)
 {
     // 1. If either token or newToken is the empty string, then throw a "SyntaxError" DOMException.
+    TRY(validate_token_not_empty(token));
+    TRY(validate_token_not_empty(new_token));
+
     // 2. If either token or newToken contains any ASCII whitespace, then throw an "InvalidCharacterError" DOMException.
-    TRY(validate_token(token));
-    TRY(validate_token(new_token));
+    TRY(validate_token_not_whitespace(token));
+    TRY(validate_token_not_whitespace(new_token));
 
     // 3. If this’s token set does not contain token, then return false.
     if (!contains(token))
@@ -264,9 +267,21 @@ void DOMTokenList::set_value(String const& value)
 }
 
 WebIDL::ExceptionOr<void> DOMTokenList::validate_token(StringView token) const
+{
+    TRY(validate_token_not_empty(token));
+    TRY(validate_token_not_whitespace(token));
+    return {};
+}
+
+WebIDL::ExceptionOr<void> DOMTokenList::validate_token_not_empty(StringView token) const
 {
     if (token.is_empty())
         return WebIDL::SyntaxError::create(realm(), "Non-empty DOM tokens are not allowed"_fly_string);
+    return {};
+}
+
+WebIDL::ExceptionOr<void> DOMTokenList::validate_token_not_whitespace(StringView token) const
+{
     if (any_of(token, Infra::is_ascii_whitespace))
         return WebIDL::InvalidCharacterError::create(realm(), "DOM tokens containing ASCII whitespace are not allowed"_fly_string);
     return {};
diff --git a/Userland/Libraries/LibWeb/DOM/DOMTokenList.h b/Userland/Libraries/LibWeb/DOM/DOMTokenList.h
index a496aaa9e2e..441e6e3b56a 100644
--- a/Userland/Libraries/LibWeb/DOM/DOMTokenList.h
+++ b/Userland/Libraries/LibWeb/DOM/DOMTokenList.h
@@ -51,6 +51,8 @@ private:
     virtual void visit_edges(Cell::Visitor&) override;
 
     WebIDL::ExceptionOr<void> validate_token(StringView token) const;
+    WebIDL::ExceptionOr<void> validate_token_not_empty(StringView token) const;
+    WebIDL::ExceptionOr<void> validate_token_not_whitespace(StringView token) const;
     void run_update_steps();
 
     String serialize_ordered_set() const;