From 6bf57abb5c23bfc4f0c4fd0693c7a5cc46e728d2 Mon Sep 17 00:00:00 2001
From: Max Bruce <Protryon@users.noreply.github.com>
Date: Mon, 23 Mar 2020 08:39:43 -0700
Subject: [PATCH] Implement GetPrototype and SetPrototype on objects (#321)

---
 src/binding.cc    | 10 ++++++++
 src/object.rs     | 28 +++++++++++++++++++++++
 tests/test_api.rs | 58 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 96 insertions(+)

diff --git a/src/binding.cc b/src/binding.cc
index ae37e0b2..c492b465 100644
--- a/src/binding.cc
+++ b/src/binding.cc
@@ -726,6 +726,10 @@ v8::Value* v8__Object__GetIndex(v8::Object& self,
   return maybe_local_to_ptr(self.Get(context, index));
 }
 
+v8::Value* v8__Object__GetPrototype(v8::Object& self) {
+  return local_to_ptr(self.GetPrototype());
+}
+
 MaybeBool v8__Object__Set(v8::Object& self, v8::Local<v8::Context> context,
                           v8::Local<v8::Value> key,
                           v8::Local<v8::Value> value) {
@@ -737,6 +741,12 @@ MaybeBool v8__Object__SetIndex(v8::Object& self, v8::Local<v8::Context> context,
   return maybe_to_maybe_bool(self.Set(context, index, value));
 }
 
+MaybeBool v8__Object__SetPrototype(v8::Object& self,
+                                   v8::Local<v8::Context> context,
+                                   v8::Local<v8::Value> prototype) {
+  return maybe_to_maybe_bool(self.SetPrototype(context, prototype));
+}
+
 MaybeBool v8__Object__CreateDataProperty(v8::Object& self,
                                          v8::Local<v8::Context> context,
                                          v8::Local<v8::Name> key,
diff --git a/src/object.rs b/src/object.rs
index 67b8c112..a44cd872 100644
--- a/src/object.rs
+++ b/src/object.rs
@@ -37,6 +37,7 @@ extern "C" {
     context: Local<Context>,
     index: u32,
   ) -> *mut Value;
+  fn v8__Object__GetPrototype(object: &Object) -> *mut Value;
   fn v8__Object__Set(
     object: &Object,
     context: Local<Context>,
@@ -49,6 +50,11 @@ extern "C" {
     index: u32,
     value: Local<Value>,
   ) -> MaybeBool;
+  fn v8__Object__SetPrototype(
+    object: &Object,
+    context: Local<Context>,
+    prototype: Local<Value>,
+  ) -> MaybeBool;
   fn v8__Object__CreateDataProperty(
     object: &Object,
     context: Local<Context>,
@@ -128,6 +134,16 @@ impl Object {
     unsafe { v8__Object__SetIndex(self, context, index, value) }.into()
   }
 
+  /// Set the prototype object. This does not skip objects marked to be
+  /// skipped by proto and it does not consult the security handler.
+  pub fn set_prototype(
+    &self,
+    context: Local<Context>,
+    prototype: Local<Value>,
+  ) -> Option<bool> {
+    unsafe { v8__Object__SetPrototype(self, context, prototype) }.into()
+  }
+
   /// Implements CreateDataProperty (ECMA-262, 7.3.4).
   ///
   /// Defines a configurable, writable, enumerable property with the given value
@@ -185,6 +201,18 @@ impl Object {
     }
   }
 
+  /// Get the prototype object. This does not skip objects marked to be
+  /// skipped by proto and it does not consult the security handler.
+  pub fn get_prototype<'a>(
+    &self,
+    scope: &mut impl ToLocal<'a>,
+  ) -> Option<Local<'a, Value>> {
+    unsafe {
+      let ptr = v8__Object__GetPrototype(self);
+      scope.to_local(ptr)
+    }
+  }
+
   /// Note: SideEffectType affects the getter only, not the setter.
   pub fn set_accessor(
     &mut self,
diff --git a/tests/test_api.rs b/tests/test_api.rs
index 0c5d53fb..b6e4f802 100644
--- a/tests/test_api.rs
+++ b/tests/test_api.rs
@@ -2805,3 +2805,61 @@ fn take_heap_snapshot() {
     assert!(s.find(r#""Eyecatcher""#).is_some());
   }
 }
+
+#[test]
+fn test_prototype_api() {
+  let _setup_guard = setup();
+  let mut params = v8::Isolate::create_params();
+  params.set_array_buffer_allocator(v8::new_default_allocator());
+  let mut isolate = v8::Isolate::new(params);
+  {
+    let mut hs = v8::HandleScope::new(&mut isolate);
+    let scope = hs.enter();
+    let context = v8::Context::new(scope);
+    let mut cs = v8::ContextScope::new(scope, context);
+    let scope = cs.enter();
+
+    let obj = v8::Object::new(scope);
+    let proto_obj = v8::Object::new(scope);
+    let key_local: v8::Local<v8::Value> =
+      v8::String::new(scope, "test_proto_key").unwrap().into();
+    let value_local: v8::Local<v8::Value> =
+      v8::String::new(scope, "test_proto_value").unwrap().into();
+    proto_obj.set(context, key_local, value_local);
+    obj.set_prototype(context, proto_obj.into());
+
+    assert!(obj
+      .get_prototype(scope)
+      .unwrap()
+      .same_value(proto_obj.into()));
+
+    let sub_gotten = obj.get(scope, context, key_local).unwrap();
+    assert!(sub_gotten.is_string());
+    let sub_gotten = sub_gotten.to_string(scope).unwrap();
+    assert_eq!(sub_gotten.to_rust_string_lossy(scope), "test_proto_value");
+  }
+  {
+    let mut hs = v8::HandleScope::new(&mut isolate);
+    let scope = hs.enter();
+    let context = v8::Context::new(scope);
+    let mut cs = v8::ContextScope::new(scope, context);
+    let scope = cs.enter();
+
+    let obj = v8::Object::new(scope);
+    obj.set_prototype(context, v8::null(scope).into());
+
+    assert!(obj.get_prototype(scope).unwrap().is_null());
+  }
+  {
+    let mut hs = v8::HandleScope::new(&mut isolate);
+    let scope = hs.enter();
+    let context = v8::Context::new(scope);
+    let mut cs = v8::ContextScope::new(scope, context);
+    let scope = cs.enter();
+
+    let val = eval(scope, context, "({ __proto__: null })").unwrap();
+    let obj = val.to_object(scope).unwrap();
+
+    assert!(obj.get_prototype(scope).unwrap().is_null());
+  }
+}