Add default implementation for Object.getPrototypeOf and Object.setPrototypeOf (#47996)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/47996

Getting and setting an Object's prototype is convoluted. Users have to
call into the global object to get the method, then call it.

This diff adds a JSI API for Object.getPrototype and Object.setPrototype
to make it easy for users.

Changelog: [Internal]

Reviewed By: fbmal7

Differential Revision: D66562549

fbshipit-source-id: 85a2e49deb9d00500544de4cc5ab123c4717398e

packages/react-native/ReactCommon/jsi/jsi/decorator.h

@@ -282,6 +282,14 @@ class RuntimeDecorator : public Base, private jsi::Instrumentation {
     plain_.setExternalMemoryPressure(obj, amt);
   }
 
+  void setPrototypeOf(const Object& object, const Value& prototype) override {
+    plain_.setPrototypeOf(object, prototype);
+  }
+
+  Value getPrototypeOf(const Object& object) override {
+    return plain_.getPrototypeOf(object);
+  }
+
   Value getProperty(const Object& o, const PropNameID& name) override {
     return plain_.getProperty(o, name);
   };
@@ -760,6 +768,16 @@ class WithRuntimeDecorator : public RuntimeDecorator<Plain, Base> {
     RD::setNativeState(o, state);
   };
 
+  void setPrototypeOf(const Object& object, const Value& prototype) override {
+    Around around{with_};
+    RD::setPrototypeOf(object, prototype);
+  }
+
+  Value getPrototypeOf(const Object& object) override {
+    Around around{with_};
+    return RD::getPrototypeOf(object);
+  }
+
   Value getProperty(const Object& o, const PropNameID& name) override {
     Around around{with_};
     return RD::getProperty(o, name);

packages/react-native/ReactCommon/jsi/jsi/jsi-inl.h

@@ -84,6 +84,10 @@ inline const Runtime::PointerValue* Runtime::getPointerValue(
   return value.data_.pointer.ptr_;
 }
 
+Value Object::getPrototype(Runtime& runtime) const {
+  return runtime.getPrototypeOf(*this);
+}
+
 inline Value Object::getProperty(Runtime& runtime, const char* name) const {
   return getProperty(runtime, String::createFromAscii(runtime, name));
 }

packages/react-native/ReactCommon/jsi/jsi/jsi.cpp

@@ -274,6 +274,20 @@ void Runtime::getPropNameIdData(
   cb(ctx, false, utf16Str.data(), utf16Str.size());
 }
 
+void Runtime::setPrototypeOf(const Object& object, const Value& prototype) {
+  auto setPrototypeOfFn = global()
+                              .getPropertyAsObject(*this, "Object")
+                              .getPropertyAsFunction(*this, "setPrototypeOf");
+  setPrototypeOfFn.call(*this, object, prototype).asObject(*this);
+}
+
+Value Runtime::getPrototypeOf(const Object& object) {
+  auto setPrototypeOfFn = global()
+                              .getPropertyAsObject(*this, "Object")
+                              .getPropertyAsFunction(*this, "getPrototypeOf");
+  return setPrototypeOfFn.call(*this, object);
+}
+
 Pointer& Pointer::operator=(Pointer&& other) noexcept {
   if (ptr_) {
     ptr_->invalidate();

packages/react-native/ReactCommon/jsi/jsi/jsi.h

@@ -339,6 +339,9 @@ class JSI_EXPORT Runtime {
       const jsi::Object&,
       std::shared_ptr<NativeState> state) = 0;
 
+  virtual void setPrototypeOf(const Object& object, const Value& prototype);
+  virtual Value getPrototypeOf(const Object& object);
+
   virtual Value getProperty(const Object&, const PropNameID& name) = 0;
   virtual Value getProperty(const Object&, const String& name) = 0;
   virtual bool hasProperty(const Object&, const PropNameID& name) = 0;
@@ -758,6 +761,16 @@ class JSI_EXPORT Object : public Pointer {
     return rt.instanceOf(*this, ctor);
   }
 
+  /// Sets \p prototype as the prototype of the object. The prototype must be
+  /// either an Object or null. If the prototype was not set successfully, this
+  /// method will throw.
+  void setPrototype(Runtime& runtime, const Value& prototype) const {
+    return runtime.setPrototypeOf(*this, prototype);
+  }
+
+  /// \return the prototype of the object
+  inline Value getPrototype(Runtime& runtime) const;
+
   /// \return the property of the object with the given ascii name.
   /// If the name isn't a property on the object, returns the
   /// undefined value.

packages/react-native/ReactCommon/jsi/jsi/test/testlib.cpp

@@ -1664,6 +1664,40 @@ TEST_P(JSITest, GetStringDataTest) {
   EXPECT_EQ(buf, str.utf16(rd));
 }
 
+TEST_P(JSITest, ObjectSetPrototype) {
+  // This Runtime Decorator is used to test the default implementation of
+  // Object.setPrototypeOf
+  class RD : public RuntimeDecorator<Runtime, Runtime> {
+   public:
+    explicit RD(Runtime& rt) : RuntimeDecorator(rt) {}
+
+    void setPrototypeOf(const Object& object, const Value& prototype) override {
+      return Runtime::setPrototypeOf(object, prototype);
+    }
+
+    Value getPrototypeOf(const Object& object) override {
+      return Runtime::getPrototypeOf(object);
+    }
+  };
+
+  RD rd = RD(rt);
+  Object child(rd);
+
+  // Tests null value as prototype
+  child.setPrototype(rd, Value::null());
+  EXPECT_TRUE(child.getPrototype(rd).isNull());
+
+  Object prototypeObj(rd);
+  prototypeObj.setProperty(rd, "someProperty", 123);
+  Value prototype(rd, prototypeObj);
+
+  child.setPrototype(rd, prototype);
+  EXPECT_EQ(child.getProperty(rd, "someProperty").getNumber(), 123);
+
+  auto getPrototypeRes = child.getPrototype(rd).asObject(rd);
+  EXPECT_EQ(getPrototypeRes.getProperty(rd, "someProperty").getNumber(), 123);
+}
+
 INSTANTIATE_TEST_CASE_P(
     Runtimes,
     JSITest,