feat(napi): implement napi_is_promise

napi/src/js_values/mod.rs

@@ -174,11 +174,16 @@ macro_rules! impl_js_value_methods {
       #[cfg(napi5)]
       pub fn is_date(&self) -> Result<bool> {
         let mut is_date = true;
-        let status = unsafe { sys::napi_is_date(self.0.env, self.0.value, &mut is_date) };
-        check_status(status)?;
+        check_status(unsafe { sys::napi_is_date(self.0.env, self.0.value, &mut is_date) })?;
         Ok(is_date)
       }
 
+      pub fn is_promise(&self) -> Result<bool> {
+        let mut is_promise = true;
+        check_status(unsafe { sys::napi_is_promise(self.0.env, self.0.value, &mut is_promise) })?;
+        Ok(is_promise)
+      }
+
       #[inline]
       pub fn is_error(&self) -> Result<bool> {
         let mut result = false;

test_module/__test__/object.spec.ts

@@ -224,3 +224,21 @@ test('testDefineProperties', (t) => {
   const descriptor = Object.getOwnPropertyDescriptor(obj, 'ro')
   t.is(descriptor?.value ?? descriptor?.get?.(), 'readonly')
 })
+
+test('is promise', (t) => {
+  t.false(bindings.testIsPromise(1))
+  t.false(bindings.testIsPromise('hello'))
+  t.false(bindings.testIsPromise({}))
+  t.false(bindings.testIsPromise(new Date()))
+  t.false(bindings.testIsPromise(Symbol()))
+
+  t.true(bindings.testIsPromise(Promise.resolve()))
+  t.true(bindings.testIsPromise(Promise.reject().catch(() => {})))
+  t.true(
+    bindings.testIsPromise(
+      new Promise((resolve) => {
+        resolve()
+      }),
+    ),
+  )
+})

test_module/src/object.rs

@@ -158,6 +158,12 @@ fn readonly_getter(ctx: CallContext) -> Result<JsString> {
   ctx.env.create_string("readonly")
 }
 
+#[js_function(1)]
+fn test_is_promise(ctx: CallContext) -> Result<JsBoolean> {
+  let obj = ctx.get::<JsObject>(0)?;
+  ctx.env.get_boolean(obj.is_promise()?)
+}
+
 pub fn register_js(module: &mut Module) -> Result<()> {
   module.create_named_method("testSetProperty", test_set_property)?;
   module.create_named_method("testGetProperty", test_get_property)?;
@@ -179,5 +185,7 @@ pub fn register_js(module: &mut Module) -> Result<()> {
   module.create_named_method("testGetElement", test_get_element)?;
   module.create_named_method("testDeleteElement", test_delete_element)?;
   module.create_named_method("testDefineProperties", test_define_properties)?;
+
+  module.create_named_method("testIsPromise", test_is_promise)?;
   Ok(())
 }