From fb049cb934dc7f417bd299b1c78d783a1e29bd6d Mon Sep 17 00:00:00 2001
From: l3ops <leops@users.noreply.github.com>
Date: Mon, 26 Oct 2020 08:57:14 +0100
Subject: [PATCH] Add Function::new_instance (#508)

---
 src/binding.cc    |  8 ++++++++
 src/function.rs   | 21 +++++++++++++++++++++
 tests/test_api.rs | 19 +++++++++++++++++++
 3 files changed, 48 insertions(+)

diff --git a/src/binding.cc b/src/binding.cc
index b978d259..315c0f63 100644
--- a/src/binding.cc
+++ b/src/binding.cc
@@ -1285,6 +1285,14 @@ const v8::Value* v8__Function__Call(const v8::Function& self,
                                 argc, const_ptr_array_to_local_array(argv)));
 }
 
+const v8::Object* v8__Function__NewInstance(const v8::Function& self,
+                                    const v8::Context& context, int argc,
+                                    const v8::Value* const argv[]) {
+  return maybe_local_to_ptr(
+      ptr_to_local(&self)->NewInstance(ptr_to_local(&context),
+                                argc, const_ptr_array_to_local_array(argv)));
+}
+
 const v8::FunctionTemplate* v8__FunctionTemplate__New(
     v8::Isolate* isolate, v8::FunctionCallback callback = nullptr) {
   return local_to_ptr(v8::FunctionTemplate::New(isolate, callback));
diff --git a/src/function.rs b/src/function.rs
index b334fbf5..8ccec99f 100644
--- a/src/function.rs
+++ b/src/function.rs
@@ -32,6 +32,12 @@ extern "C" {
     argc: int,
     argv: *const *const Value,
   ) -> *const Value;
+  fn v8__Function__NewInstance(
+    this: *const Function,
+    context: *const Context,
+    argc: int,
+    argv: *const *const Value,
+  ) -> *const Object;
 
   fn v8__FunctionCallbackInfo__GetReturnValue(
     info: *const FunctionCallbackInfo,
@@ -326,4 +332,19 @@ impl Function {
       })
     }
   }
+
+  pub fn new_instance<'s>(
+    &self,
+    scope: &mut HandleScope<'s>,
+    args: &[Local<Value>],
+  ) -> Option<Local<'s, Object>> {
+    let args = Local::slice_into_raw(args);
+    let argc = int::try_from(args.len()).unwrap();
+    let argv = args.as_ptr();
+    unsafe {
+      scope.cast_local(|sd| {
+        v8__Function__NewInstance(self, sd.get_current_context(), argc, argv)
+      })
+    }
+  }
 }
diff --git a/tests/test_api.rs b/tests/test_api.rs
index e0e1c78e..3671ab40 100644
--- a/tests/test_api.rs
+++ b/tests/test_api.rs
@@ -1671,6 +1671,25 @@ fn function() {
   }
 }
 
+#[test]
+fn constructor() {
+  let _setup_guard = setup();
+  let isolate = &mut v8::Isolate::new(Default::default());
+
+  {
+    let scope = &mut v8::HandleScope::new(isolate);
+    let context = v8::Context::new(scope);
+    let scope = &mut v8::ContextScope::new(scope, context);
+    let global = context.global(scope);
+    let array_name = v8::String::new(scope, "Array").unwrap();
+    let array_constructor = global.get(scope, array_name.into()).unwrap();
+    let array_constructor =
+      v8::Local::<v8::Function>::try_from(array_constructor).unwrap();
+    let array = array_constructor.new_instance(scope, &[]).unwrap();
+    v8::Local::<v8::Array>::try_from(array).unwrap();
+  }
+}
+
 extern "C" fn promise_reject_callback(msg: v8::PromiseRejectMessage) {
   let scope = &mut unsafe { v8::CallbackScope::new(&msg) };
   let event = msg.get_event();