Add v8::FunctionCallbackInfo::NewTarget bindings (#898)

src/binding.cc

@@ -1714,6 +1714,11 @@ const v8::Value* v8__FunctionCallbackInfo__Data(
   return local_to_ptr(self.Data());
 }
 
+const v8::Value* v8__FunctionCallbackInfo__NewTarget(
+    const v8::FunctionCallbackInfo<v8::Value>& self) {
+  return local_to_ptr(self.NewTarget());
+}
+
 void v8__ReturnValue__Set(v8::ReturnValue<v8::Value>* self,
                           const v8::Value& value) {
   self->Set(ptr_to_local(&value));

src/function.rs

@@ -66,6 +66,9 @@ extern "C" {
   fn v8__FunctionCallbackInfo__Data(
     this: *const FunctionCallbackInfo,
   ) -> *const Value;
+  fn v8__FunctionCallbackInfo__NewTarget(
+    this: *const FunctionCallbackInfo,
+  ) -> *const Value;
 
   fn v8__PropertyCallbackInfo__GetReturnValue(
     this: *const PropertyCallbackInfo,
@@ -215,6 +218,13 @@ impl<'s> FunctionCallbackArguments<'s> {
         .unwrap()
     }
   }
+
+  /// For construct calls, this returns the "new.target" value.
+  pub fn new_target(&self) -> Local<'s, Value> {
+    unsafe {
+      Local::from_raw(v8__FunctionCallbackInfo__NewTarget(self.info)).unwrap()
+    }
+  }
 }
 
 #[derive(Debug)]

tests/test_api.rs

@@ -1952,6 +1952,21 @@ fn fn_callback(
   rv.set(s.into());
 }
 
+fn fn_callback_new(
+  scope: &mut v8::HandleScope,
+  args: v8::FunctionCallbackArguments,
+  mut rv: v8::ReturnValue,
+) {
+  assert_eq!(args.length(), 0);
+  assert!(args.new_target().is_object());
+  let recv = args.this();
+  let key = v8::String::new(scope, "works").unwrap();
+  let value = v8::Boolean::new(scope, true);
+  assert!(recv.set(scope, key.into(), value.into()).unwrap());
+  assert!(rv.get(scope).is_undefined());
+  rv.set(recv.into());
+}
+
 fn fn_callback2(
   scope: &mut v8::HandleScope,
   args: v8::FunctionCallbackArguments,
@@ -2073,6 +2088,16 @@ fn function() {
     let result = eval(scope, "f.prototype").unwrap();
     assert!(result.is_undefined());
     assert!(eval(scope, "new f()").is_none()); // throws
+
+    let function = v8::Function::builder(fn_callback_new).build(scope).unwrap();
+    let name = v8::String::new(scope, "f2").unwrap();
+    global.set(scope, name.into(), function.into()).unwrap();
+    let f2: v8::Local<v8::Object> =
+      eval(scope, "new f2()").unwrap().try_into().unwrap();
+    let key = v8::String::new(scope, "works").unwrap();
+    let value = f2.get(scope, key.into()).unwrap();
+    assert!(value.is_boolean());
+    assert!(value.boolean_value(scope));
   }
 }