From a942ef374897d85da38e9c8904574f8376555388 Mon Sep 17 00:00:00 2001
From: Chi Tsai <chitsai@meta.com>
Date: Thu, 9 Jan 2025 05:15:51 -0800
Subject: [PATCH] Add Hermes implementation for Object.create with prototype

Summary:
Adds the implementation `createObjectWithPrototype` JSI method for
Hermes runtime.

Grafted from 1053185886992b918021c4d2578a0807f797dd00 (D66487948)
- Grafted path xplat/static_h to xplat/hermes

Reviewed By: tmikov

Differential Revision: D67412929

fbshipit-source-id: a283ffc775494f7df2bdcf9a91ada188b673c071
---
 API/hermes/hermes.cpp     | 14 ++++++++++++++
 unittests/API/APITest.cpp | 16 ++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/API/hermes/hermes.cpp b/API/hermes/hermes.cpp
index f5e6c29c719..0fec8a6637b 100644
--- a/API/hermes/hermes.cpp
+++ b/API/hermes/hermes.cpp
@@ -632,6 +632,7 @@ class HermesRuntimeImpl final : public HermesRuntime,
   jsi::Object createObject() override;
   jsi::Object createObject(std::shared_ptr<jsi::HostObject> ho) override;
   std::shared_ptr<jsi::HostObject> getHostObject(const jsi::Object &) override;
+  jsi::Object createObjectWithPrototype(const jsi::Value &prototype) override;
   jsi::HostFunctionType &getHostFunction(const jsi::Function &) override;
   bool hasNativeState(const jsi::Object &) override;
   std::shared_ptr<jsi::NativeState> getNativeState(
@@ -1874,6 +1875,19 @@ jsi::Object HermesRuntimeImpl::createObject(
   return add<jsi::Object>(*objRes);
 }
 
+jsi::Object HermesRuntimeImpl::createObjectWithPrototype(
+    const jsi::Value &prototype) {
+  if (!prototype.isObject() && !prototype.isNull()) {
+    throw jsi::JSError(
+        *this, "Object prototype argument must be an Object or null");
+  }
+
+  auto object = vm::JSObject::create(
+      runtime_,
+      vm::Handle<vm::JSObject>::dyn_vmcast(vmHandleFromValue(prototype)));
+  return add<jsi::Object>(object.getHermesValue());
+}
+
 std::shared_ptr<jsi::HostObject> HermesRuntimeImpl::getHostObject(
     const jsi::Object &obj) {
   const vm::HostObjectProxy *proxy =
diff --git a/unittests/API/APITest.cpp b/unittests/API/APITest.cpp
index afc1d94959a..c3928848549 100644
--- a/unittests/API/APITest.cpp
+++ b/unittests/API/APITest.cpp
@@ -1294,6 +1294,22 @@ TEST_P(HermesRuntimeTest, SetPrototypeOf) {
   EXPECT_THROW(child.setPrototype(*rt, Value(1)), JSError);
 }
 
+TEST_P(HermesRuntimeTest, CreateObjectWithPrototype) {
+  Object prototypeObj(*rt);
+  prototypeObj.setProperty(*rt, "someProperty", 123);
+  Value prototype(*rt, prototypeObj);
+
+  Object child = Object::create(*rt, prototype);
+  EXPECT_EQ(child.getProperty(*rt, "someProperty").getNumber(), 123);
+
+  // Tests null value as prototype
+  child = Object::create(*rt, Value::null());
+  EXPECT_TRUE(child.getPrototype(*rt).isNull());
+
+  // Throw when prototype is neither an Object nor null
+  EXPECT_THROW(Object::create(*rt, Value(1)), JSError);
+}
+
 INSTANTIATE_TEST_CASE_P(
     Runtimes,
     HermesRuntimeTest,