Add v8::Value::InstanceOf bindings (#879)

src/binding.cc

@@ -682,6 +682,12 @@ const v8::Boolean* v8__Value__ToBoolean(const v8::Value& self,
   return local_to_ptr(self.ToBoolean(isolate));
 }
 
+void v8__Value__InstanceOf(const v8::Value& self, const v8::Context& context,
+                           const v8::Object& object, v8::Maybe<bool>* out) {
+  v8::Value* self_non_const = const_cast<v8::Value*>(&self);
+  *out = self_non_const->InstanceOf(ptr_to_local(&context), ptr_to_local(&object));
+}
+
 void v8__Value__NumberValue(const v8::Value& self, const v8::Context& context,
                             v8::Maybe<double>* out) {
   *out = self.NumberValue(ptr_to_local(&context));

src/value.rs

@@ -72,7 +72,12 @@ extern "C" {
   fn v8__Value__IsModuleNamespaceObject(this: *const Value) -> bool;
   fn v8__Value__StrictEquals(this: *const Value, that: *const Value) -> bool;
   fn v8__Value__SameValue(this: *const Value, that: *const Value) -> bool;
-
+  fn v8__Value__InstanceOf(
+    this: *const Value,
+    context: *const Context,
+    object: *const Object,
+    out: *mut Maybe<bool>,
+  );
   fn v8__Value__ToBigInt(
     this: *const Value,
     context: *const Context,
@@ -551,6 +556,23 @@ impl Value {
     .unwrap()
   }
 
+  pub fn instance_of<'s>(
+    &self,
+    scope: &mut HandleScope<'s>,
+    object: Local<Object>,
+  ) -> Option<bool> {
+    let mut out = Maybe::<bool>::default();
+    unsafe {
+      v8__Value__InstanceOf(
+        self,
+        &*scope.get_current_context(),
+        &*object,
+        &mut out,
+      );
+    }
+    out.into()
+  }
+
   pub fn number_value<'s>(&self, scope: &mut HandleScope<'s>) -> Option<f64> {
     let mut out = Maybe::<f64>::default();
     unsafe {

tests/test_api.rs

@@ -5884,3 +5884,22 @@ fn current_stack_trace() {
   .unwrap();
   assert_eq!(too_deep, 5);
 }
+
+#[test]
+fn instance_of() {
+  let _setup_guard = setup();
+
+  let mut isolate = v8::Isolate::new(Default::default());
+  let mut scope = v8::HandleScope::new(&mut isolate);
+  let context = v8::Context::new(&mut scope);
+  let mut scope = v8::ContextScope::new(&mut scope, context);
+  let global = context.global(&mut scope);
+  let array_name = v8::String::new(&mut scope, "Array").unwrap();
+  let array_constructor = global.get(&mut scope, array_name.into()).unwrap();
+  let array_constructor =
+    v8::Local::<v8::Object>::try_from(array_constructor).unwrap();
+  let array: v8::Local<v8::Value> =
+    v8::Array::new_with_elements(&mut scope, &[]).into();
+
+  assert!(array.instance_of(&mut scope, array_constructor).unwrap());
+}