From 896f8be09f2abb490d0a8e391af38fbd6e54d7dd Mon Sep 17 00:00:00 2001
From: Andreas Kling <andreas@ladybird.org>
Date: Wed, 19 Mar 2025 10:38:22 -0500
Subject: [PATCH] LibJS: Add fast path for strings in Value::to_property_key()

If the Value is already a primitive string, we can skip all the
conversion ceremony and return a PropertyKey right away.
---
 Libraries/LibJS/Runtime/Value.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Libraries/LibJS/Runtime/Value.cpp b/Libraries/LibJS/Runtime/Value.cpp
index 50f0ac2f826..6da7a6b7ad8 100644
--- a/Libraries/LibJS/Runtime/Value.cpp
+++ b/Libraries/LibJS/Runtime/Value.cpp
@@ -898,6 +898,10 @@ ThrowCompletionOr<PropertyKey> Value::to_property_key(VM& vm) const
     if (is_int32() && as_i32() >= 0)
         return PropertyKey { as_i32() };
 
+    // OPTIMIZATION: If this is already a string, we can skip all the ceremony.
+    if (is_string())
+        return PropertyKey { as_string().utf8_string() };
+
     // 1. Let key be ? ToPrimitive(argument, string).
     auto key = TRY(to_primitive(vm, PreferredType::String));