fix(perf_hooks): align default import export keys

changelog.d/9885-perf-hooks-default-export-keys.md

@@ -0,0 +1,3 @@
+### Fixed
+
+- Match Node's `node:perf_hooks` default-import keys while preserving namespace `default` and shared export identity.

crates/perry-dispatch/src/cjs_default_modules.rs

@@ -47,6 +47,7 @@ cjs_default_namespace_modules!(
     "path",
     "path.posix",
     "path.win32",
+    "perf_hooks",
     "process",
     "punycode",
     "querystring",

crates/perry-hir/src/lower/tests.rs

@@ -582,6 +582,39 @@ export function perfHooksDefault() {
     ));
 }
 
+#[test]
+fn native_perf_hooks_default_import_reads_cjs_namespace() {
+    let source = r#"
+import hooks from "node:perf_hooks";
+export function perfHooksDefaultImport() {
+  return hooks;
+}
+"#;
+    let module = perry_parser::parse_typescript(source, "perf-hooks-default-import.ts")
+        .expect("source parses");
+    let hir = super::lower_module(
+        &module,
+        "perf-hooks-default-import",
+        "perf-hooks-default-import.ts",
+    )
+    .expect("source lowers");
+    let function = hir
+        .functions
+        .iter()
+        .find(|function| function.name == "perfHooksDefaultImport")
+        .expect("exported function is lowered");
+
+    assert!(matches!(
+        function.body.as_slice(),
+        [Stmt::Return(Some(crate::ir::Expr::PropertyGet {
+            object,
+            property,
+            ..
+        }))] if property == "default"
+            && matches!(object.as_ref(), crate::ir::Expr::NativeModuleRef(module) if module == "perf_hooks")
+    ));
+}
+
 #[test]
 fn test_lower_type_param_scoping() {
     let mut ctx = make_ctx();

crates/perry-runtime/src/object/native_module.rs

@@ -702,14 +702,6 @@ pub(crate) fn cjs_default_export_value(module_name: &str) -> Option<f64> {
             "dgram".len(),
         )),
         "module" => Some(bound_native_callable_export_value("module", "Module")),
-        // node:perf_hooks has no distinct CJS shape — `module.exports` IS the
-        // namespace, and `default` is listed among its keys. Resolving to the
-        // same tag keeps `hooks.default.performance === hooks.performance`
-        // (the `performance` singleton resolves identically from either).
-        "perf_hooks" => Some(js_create_native_module_namespace(
-            b"perf_hooks".as_ptr(),
-            "perf_hooks".len(),
-        )),
         "process" => Some(js_create_native_module_namespace(
             b"process".as_ptr(),
             "process".len(),
@@ -812,6 +804,7 @@ fn should_cache_native_module_namespace(module_name: &str) -> bool {
             | "path.default"
             | "path.posix.default"
             | "path.win32.default"
+            | "perf_hooks.default"
             | "punycode"
             | "punycode.default"
             | "punycode.ucs2"
@@ -936,12 +929,13 @@ unsafe fn native_module_property_by_name_impl(
     // `typeof performance === "object"`, `performance.timeOrigin` (a
     // constant), `performance.now` (a callable export), and
     // `constants.NODE_PERFORMANCE_GC_*` (constants) all dispatch coherently.
-    if module_name == "perf_hooks" && property_name == "performance" {
+    if matches!(module_name, "perf_hooks" | "perf_hooks.default") && property_name == "performance"
+    {
         // Singleton so `require("perf_hooks").performance` and the global
         // `performance` are the same object (Node identity guarantee, #1327).
         return crate::perf_hooks::performance_namespace();
     }
-    if module_name == "perf_hooks" && property_name == "constants" {
+    if matches!(module_name, "perf_hooks" | "perf_hooks.default") && property_name == "constants" {
         // Its OWN tag. Sharing the `perf_hooks` tag made every read of the
         // constants object resolve against the MODULE's surface, so
         // `Object.keys(constants)` enumerated the export list instead of the

crates/perry-runtime/src/object/native_module/module_keys.rs

@@ -1281,6 +1281,22 @@ const VM_MODULE_NAMESPACE_KEYS: &[&[u8]] = &[
 
 const VM_CONSTANTS_KEYS: &[&[u8]] = &[b"USE_MAIN_CONTEXT_DEFAULT_LOADER", b"DONT_CONTEXTIFY"];
 
+const PERF_HOOKS_DEFAULT_KEYS: &[&[u8]] = &[
+    b"Performance",
+    b"PerformanceEntry",
+    b"PerformanceMark",
+    b"PerformanceMeasure",
+    b"PerformanceObserver",
+    b"PerformanceObserverEntryList",
+    b"PerformanceResourceTiming",
+    b"monitorEventLoopDelay",
+    b"eventLoopUtilization",
+    b"timerify",
+    b"createHistogram",
+    b"performance",
+    b"constants",
+];
+
 // Linux-only open() flags: Node only enumerates these on platforms whose libc
 // defines them (e.g. `O_DIRECT`/`O_NOATIME` are absent on macOS), so gate the
 // enumerable-key tail by target so `Object.keys(constants)` matches Node here.
@@ -1862,6 +1878,7 @@ pub(crate) fn native_module_enumerable_keys(module_name: &str) -> Option<&'stati
             b"constants",
             b"default",
         ]),
+        "perf_hooks.default" => Some(PERF_HOOKS_DEFAULT_KEYS),
         "perf_hooks.constants" => Some(&[
             b"NODE_PERFORMANCE_GC_MAJOR",
             b"NODE_PERFORMANCE_GC_MINOR",

crates/perry-runtime/src/object/native_module_dispatch.rs

@@ -390,6 +390,7 @@ mod cjs_default_dispatch_tests {
         "path.default",
         "path.posix.default",
         "path.win32.default",
+        "perf_hooks.default",
         "process.default",
         "punycode.default",
         "querystring.default",