From 81c2584bb269911f8090ad6ff837d30f0ae359ed Mon Sep 17 00:00:00 2001
From: Don Isaac <donald.isaac@gmail.com>
Date: Sun, 6 Sep 2026 16:40:06 -0400
Subject: [PATCH] fix: SetFunctionName always includes prefix

---
 .../builtins/ecmascript_function.rs           | 22 +++++++++++--------
 tests/expectations.json                       |  5 -----
 tests/metrics.json                            |  4 ++--
 3 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/nova_vm/src/ecmascript/builtins/ecmascript_function.rs b/nova_vm/src/ecmascript/builtins/ecmascript_function.rs
index d2ebc374b..78a534cb9 100644
--- a/nova_vm/src/ecmascript/builtins/ecmascript_function.rs
+++ b/nova_vm/src/ecmascript/builtins/ecmascript_function.rs
@@ -1095,15 +1095,19 @@ pub(crate) fn set_function_name<'a>(
             // a. Let description be name's [[Description]] value.
             // b. If description is undefined, set name to the empty String.
             // c. Else, set name to the string-concatenation of "[", description, and "]".
-            s.description(agent)
-                .map_or(String::EMPTY_STRING, |descriptor| {
-                    let descriptor = descriptor.to_string_lossy_(agent);
-                    String::from_string(
-                        agent,
-                        format!("{}[{descriptor}]", prefix_into_str(prefix)),
-                        gc,
-                    )
-                })
+            if let Some(descriptor) = s.description(agent) {
+                let descriptor = descriptor.to_string_lossy_(agent);
+                String::from_string(
+                    agent,
+                    format!("{}[{descriptor}]", prefix_into_str(prefix)),
+                    gc,
+                )
+            } else if let Some(prefix) = prefix {
+                // Step 5 applies even when description is None
+                String::from_static_str(agent, prefix.into_str(), gc)
+            } else {
+                String::EMPTY_STRING
+            }
         }
 
         PropertyKey::Integer(integer) => String::from_string(
diff --git a/tests/expectations.json b/tests/expectations.json
index 8fb7142c7..487d02552 100644
--- a/tests/expectations.json
+++ b/tests/expectations.json
@@ -5787,8 +5787,6 @@
   "language/expressions/logical-or/tco-right.js": "FAIL",
   "language/expressions/multiplication/S11.5.1_A4_T7.js": "FAIL",
   "language/expressions/object/computed-property-name-topropertykey-before-value-evaluation.js": "FAIL",
-  "language/expressions/object/fn-name-accessor-get.js": "FAIL",
-  "language/expressions/object/fn-name-accessor-set.js": "FAIL",
   "language/expressions/object/identifier-shorthand-static-init-await-valid.js": "FAIL",
   "language/expressions/object/method-definition/generator-prototype-prop.js": "FAIL",
   "language/expressions/object/method-definition/static-init-await-binding-accessor.js": "FAIL",
@@ -6157,8 +6155,6 @@
   "language/statements/class/decorator/syntax/valid/decorator-member-expr-identifier-reference.js": "FAIL",
   "language/statements/class/decorator/syntax/valid/decorator-parenthesized-expr-identifier-reference.js": "FAIL",
   "language/statements/class/definition/constructor-strict-by-default.js": "FAIL",
-  "language/statements/class/definition/fn-name-accessor-get.js": "FAIL",
-  "language/statements/class/definition/fn-name-accessor-set.js": "FAIL",
   "language/statements/class/elements/arrow-body-derived-cls-direct-eval-contains-superproperty-1.js": "FAIL",
   "language/statements/class/elements/arrow-body-derived-cls-direct-eval-contains-superproperty-2.js": "FAIL",
   "language/statements/class/elements/arrow-body-direct-eval-err-contains-arguments.js": "FAIL",
@@ -6540,7 +6536,6 @@
   "staging/sm/Function/function-caller-restrictions.js": "FAIL",
   "staging/sm/Function/function-name-assignment.js": "FAIL",
   "staging/sm/Function/function-name-for.js": "FAIL",
-  "staging/sm/Function/function-name-method.js": "FAIL",
   "staging/sm/Function/function-name-property.js": "FAIL",
   "staging/sm/Function/function-toString-builtin-name.js": "FAIL",
   "staging/sm/Function/function-toString-builtin.js": "FAIL",
diff --git a/tests/metrics.json b/tests/metrics.json
index e81399db9..a3f6bc541 100644
--- a/tests/metrics.json
+++ b/tests/metrics.json
@@ -1,8 +1,8 @@
 {
   "results": {
     "crash": 52,
-    "fail": 6785,
-    "pass": 40515,
+    "fail": 6780,
+    "pass": 40520,
     "skip": 3326,
     "timeout": 18,
     "unresolved": 37