From c5315ddaa2dd492f5e3b0099076db918cf15fcb9 Mon Sep 17 00:00:00 2001
From: Andrew DiZenzo <andrewdizenzojhu@gmail.com>
Date: Wed, 3 Jun 2026 15:51:01 +0000
Subject: [PATCH] Align captured Object.assign value shape

---
 crates/perry-hir/src/lower/expr_member.rs     | 20 +++++++++++++++++++
 .../perry-runtime/src/object/global_this.rs   |  9 ++++++++-
 .../object/captured-object-assign.ts          | 13 ++++++++++++
 3 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 test-parity/node-suite/object/captured-object-assign.ts

diff --git a/crates/perry-hir/src/lower/expr_member.rs b/crates/perry-hir/src/lower/expr_member.rs
index fd4d25fa76..488b7c2acd 100644
--- a/crates/perry-hir/src/lower/expr_member.rs
+++ b/crates/perry-hir/src/lower/expr_member.rs
@@ -1768,9 +1768,29 @@ fn lower_member_inner(ctx: &mut LoweringContext, member: &ast::MemberExpr) -> Re
                             ast::MemberProp::Computed(_) => true,
                             _ => false,
                         };
+                    let outer_is_reified_object_static_value = property == "Object"
+                        && matches!(
+                            &member.prop,
+                            ast::MemberProp::Ident(p) if matches!(
+                                p.sym.as_ref(),
+                                "assign"
+                                    | "create"
+                                    | "defineProperty"
+                                    | "entries"
+                                    | "freeze"
+                                    | "fromEntries"
+                                    | "getOwnPropertyDescriptor"
+                                    | "getOwnPropertyNames"
+                                    | "getPrototypeOf"
+                                    | "hasOwn"
+                                    | "keys"
+                                    | "values"
+                            )
+                        );
                     if !outer_is_prototype_or_proto
                         && !receiver_is_namespace_value
                         && !outer_is_websocket_static
+                        && !outer_is_reified_object_static_value
                     {
                         object_expr = Expr::GlobalGet(0);
                     }
diff --git a/crates/perry-runtime/src/object/global_this.rs b/crates/perry-runtime/src/object/global_this.rs
index 0d9c621145..ca7fc55458 100644
--- a/crates/perry-runtime/src/object/global_this.rs
+++ b/crates/perry-runtime/src/object/global_this.rs
@@ -3103,7 +3103,14 @@ fn install_builtin_constructor_statics(name: &str, ctor: *mut crate::closure::Cl
                 1,
                 false,
             );
-            install_constructor_static(ctor, "assign", object_assign_thunk as *const u8, 1, true);
+            install_constructor_static_with_call_arity(
+                ctor,
+                "assign",
+                object_assign_thunk as *const u8,
+                2,
+                1,
+                true,
+            );
             install_constructor_static(ctor, "hasOwn", object_hasown_thunk as *const u8, 2, false);
         }
         "Array" => {
diff --git a/test-parity/node-suite/object/captured-object-assign.ts b/test-parity/node-suite/object/captured-object-assign.ts
new file mode 100644
index 0000000000..991f0cba78
--- /dev/null
+++ b/test-parity/node-suite/object/captured-object-assign.ts
@@ -0,0 +1,13 @@
+const assign = Object.assign;
+
+console.log("assign typeof:", typeof assign);
+console.log("assign name:", assign.name);
+console.log("assign length:", assign.length);
+
+const target: any = { base: 1 };
+const out: any = assign(target, { a: 2 }, { b: 3 });
+
+console.log("same target:", out === target);
+console.log("keys:", Object.keys(out).join(","));
+console.log("values:", [out.base, out.a, out.b].join(","));
+console.log("fresh copy:", JSON.stringify(assign({}, { x: 1 }, { y: 2 })));