n-api: make napi_get_property_names return strings

The documentation says that this method returns an array of strings.
Currently, it does not do so for indices. Resolve that by telling
V8 explicitly to convert to string.

PR-URL: #27524
Fixes: #27496
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Author: addaleax

src/js_native_api_v8.cc

@@ -870,7 +870,14 @@ napi_status napi_get_property_names(napi_env env,
   v8::Local<v8::Object> obj;
   CHECK_TO_OBJECT(env, context, obj, object);
 
-  auto maybe_propertynames = obj->GetPropertyNames(context);
+  v8::MaybeLocal<v8::Array> maybe_propertynames = obj->GetPropertyNames(
+    context,
+    v8::KeyCollectionMode::kIncludePrototypes,
+    static_cast<v8::PropertyFilter>(
+        v8::PropertyFilter::ONLY_ENUMERABLE |
+        v8::PropertyFilter::SKIP_SYMBOLS),
+    v8::IndexFilter::kIncludeIndices,
+    v8::KeyConversionMode::kConvertToString);
 
   CHECK_MAYBE_EMPTY(env, maybe_propertynames, napi_generic_failure);
 

test/js-native-api/test_object/test.js

@@ -202,3 +202,26 @@ assert.strictEqual(newObject.test_string, 'test string');
   assert.strictEqual(test_object.Delete(obj, 'foo'), true);
   assert.strictEqual(obj.foo, 'baz');
 }
+
+{
+  // Verify that napi_get_property_names gets the right set of property names,
+  // i.e.: includes prototypes, only enumerable properties, skips symbols,
+  // and includes indices and converts them to strings.
+
+  const object = Object.create({
+    inherited: 1
+  });
+
+  object.normal = 2;
+  object[Symbol('foo')] = 3;
+  Object.defineProperty(object, 'unenumerable', {
+    value: 4,
+    enumerable: false,
+    writable: true,
+    configurable: true
+  });
+  object[5] = 5;
+
+  assert.deepStrictEqual(test_object.GetPropertyNames(object),
+                         ['5', 'normal', 'inherited']);
+}

test/js-native-api/test_object/test_object.c

@@ -63,6 +63,25 @@ static napi_value GetNamed(napi_env env, napi_callback_info info) {
   return output;
 }
 
+static napi_value GetPropertyNames(napi_env env, napi_callback_info info) {
+  size_t argc = 1;
+  napi_value args[1];
+  NAPI_CALL(env, napi_get_cb_info(env, info, &argc, args, NULL, NULL));
+
+  NAPI_ASSERT(env, argc >= 1, "Wrong number of arguments");
+
+  napi_valuetype value_type0;
+  NAPI_CALL(env, napi_typeof(env, args[0], &value_type0));
+
+  NAPI_ASSERT(env, value_type0 == napi_object,
+      "Wrong type of arguments. Expects an object as first argument.");
+
+  napi_value output;
+  NAPI_CALL(env, napi_get_property_names(env, args[0], &output));
+
+  return output;
+}
+
 static napi_value Set(napi_env env, napi_callback_info info) {
   size_t argc = 3;
   napi_value args[3];
@@ -325,6 +344,7 @@ napi_value Init(napi_env env, napi_value exports) {
   napi_property_descriptor descriptors[] = {
     DECLARE_NAPI_PROPERTY("Get", Get),
     DECLARE_NAPI_PROPERTY("GetNamed", GetNamed),
+    DECLARE_NAPI_PROPERTY("GetPropertyNames", GetPropertyNames),
     DECLARE_NAPI_PROPERTY("Set", Set),
     DECLARE_NAPI_PROPERTY("SetNamed", SetNamed),
     DECLARE_NAPI_PROPERTY("Has", Has),