Add Object::creation_context() (#255)

And also Array::creation_context(), Function::creation_context(), etc.,
because they inherit from Object.

src/binding.cc

@@ -710,6 +710,10 @@ int v8__Object__GetIdentityHash(v8::Object& self) {
   return self.GetIdentityHash();
 }
 
+v8::Context* v8__Object__CreationContext(v8::Object& self) {
+  return local_to_ptr(self.CreationContext());
+}
+
 v8::Array* v8__Array__New(v8::Isolate* isolate, int length) {
   return local_to_ptr(v8::Array::New(isolate, length));
 }

src/object.rs

@@ -52,6 +52,7 @@ extern "C" {
     attr: PropertyAttribute,
   ) -> MaybeBool;
   fn v8__Object__GetIdentityHash(object: &Object) -> int;
+  fn v8__Object__CreationContext(object: &Object) -> *mut Context;
 
   fn v8__Array__New(isolate: *mut Isolate, length: int) -> *mut Array;
 }
@@ -163,6 +164,17 @@ impl Object {
   pub fn get_identity_hash(&self) -> int {
     unsafe { v8__Object__GetIdentityHash(self) }
   }
+
+  /// Returns the context in which the object was created.
+  pub fn creation_context<'a>(
+    &self,
+    scope: &mut impl ToLocal<'a>,
+  ) -> Local<'a, Context> {
+    unsafe {
+      let ptr = v8__Object__CreationContext(self);
+      scope.to_local(ptr).unwrap()
+    }
+  }
 }
 
 impl Array {

tests/test_api.rs

@@ -1023,6 +1023,9 @@ fn object() {
       &[v1, v2],
     );
     assert!(!object.is_null_or_undefined());
+    let lhs = object.creation_context(scope).global(scope);
+    let rhs = context.global(scope);
+    assert!(lhs.strict_equals(rhs.into()));
 
     let object_ = v8::Object::new(scope);
     assert!(!object_.is_null_or_undefined());
@@ -1050,6 +1053,9 @@ fn array() {
     let s2 = v8::String::new(scope, "b").unwrap();
     let index2 = v8::Integer::new(scope, 1);
     let array = v8::Array::new(scope, 2);
+    let lhs = array.creation_context(scope).global(scope);
+    let rhs = context.global(scope);
+    assert!(lhs.strict_equals(rhs.into()));
     array.set(context, index1.into(), s1.into());
     array.set(context, index2.into(), s2.into());
 
@@ -1296,6 +1302,9 @@ fn function() {
     let function = fn_template
       .get_function(scope, context)
       .expect("Unable to create function");
+    let lhs = function.creation_context(scope).global(scope);
+    let rhs = context.global(scope);
+    assert!(lhs.strict_equals(rhs.into()));
     function
       .call(scope, context, recv, &[])
       .expect("Function call failed");