src: enable type cast checks in tests (#1581)

doc/value.md

@@ -86,6 +86,19 @@ In order to enforce expected type, use `Napi::Value::Is*()` methods to check
 the type before calling `Napi::Value::As()`, or compile with definition
 `NODE_ADDON_API_ENABLE_TYPE_CHECK_ON_AS` to enforce type checks.
 
+### UnsafeAs
+
+```cpp
+template <typename T> T Napi::Value::UnsafeAs() const;
+```
+
+Casts to another type of `Napi::Value`, when the actual type is known or
+assumed.
+
+This conversion does not coerce the type. This does not check the type even if
+`NODE_ADDON_API_ENABLE_TYPE_CHECK_ON_AS` is defined. This indicates intentional
+unsafe type cast. Use `Napi::Value::As()` if possible.
+
 ### Env
 
 ```cpp

napi-inl.h

@@ -896,6 +896,16 @@ inline T Value::As() const {
   return T(_env, _value);
 }
 
+template <typename T>
+inline T Value::UnsafeAs() const {
+  return T(_env, _value);
+}
+
+// static
+inline void Value::CheckCast(napi_env /* env */, napi_value value) {
+  NAPI_CHECK(value != nullptr, "Value::CheckCast", "empty value");
+}
+
 inline MaybeOrValue<Boolean> Value::ToBoolean() const {
   napi_value result;
   napi_status status = napi_coerce_to_bool(_env, _value, &result);
@@ -1303,12 +1313,15 @@ inline Symbol Symbol::New(napi_env env, napi_value description) {
 
 inline MaybeOrValue<Symbol> Symbol::WellKnown(napi_env env,
                                               const std::string& name) {
+  // No need to check if the return value is a symbol or undefined.
+  // Well known symbols are definite and it is an develop time error
+  // if the symbol does not exist.
 #if defined(NODE_ADDON_API_ENABLE_MAYBE)
   Value symbol_obj;
   Value symbol_value;
   if (Napi::Env(env).Global().Get("Symbol").UnwrapTo(&symbol_obj) &&
       symbol_obj.As<Object>().Get(name).UnwrapTo(&symbol_value)) {
-    return Just<Symbol>(symbol_value.As<Symbol>());
+    return Just<Symbol>(symbol_value.UnsafeAs<Symbol>());
   }
   return Nothing<Symbol>();
 #else
@@ -1317,7 +1330,7 @@ inline MaybeOrValue<Symbol> Symbol::WellKnown(napi_env env,
       .Get("Symbol")
       .As<Object>()
       .Get(name)
-      .As<Symbol>();
+      .UnsafeAs<Symbol>();
 #endif
 }
 
@@ -1535,7 +1548,10 @@ inline void Object::CheckCast(napi_env env, napi_value value) {
   napi_valuetype type;
   napi_status status = napi_typeof(env, value, &type);
   NAPI_CHECK(status == napi_ok, "Object::CheckCast", "napi_typeof failed");
-  NAPI_INTERNAL_CHECK_EQ(type, napi_object, "%d", "Object::CheckCast");
+  NAPI_INTERNAL_CHECK(type == napi_object || type == napi_function,
+                      "Object::CheckCast",
+                      "Expect napi_object or napi_function, but got %d.",
+                      type);
 }
 
 inline Object::Object() : TypeTaggable() {}

napi.h

@@ -461,6 +461,8 @@ class Value {
   template <typename T>
   static Value From(napi_env env, const T& value);
 
+  static void CheckCast(napi_env env, napi_value value);
+
   /// Converts to a Node-API value primitive.
   ///
   /// If the instance is _empty_, this returns `nullptr`.
@@ -527,6 +529,10 @@ class Value {
   template <typename T>
   T As() const;
 
+  // Unsafe Value::As(), should be avoided.
+  template <typename T>
+  T UnsafeAs() const;
+
   MaybeOrValue<Boolean> ToBoolean()
       const;  ///< Coerces a value to a JavaScript boolean.
   MaybeOrValue<Number> ToNumber()

test/async_worker.cc

@@ -20,14 +20,14 @@ class TestWorkerWithUserDefRecv : public AsyncWorker {
   static void DoWorkWithAsyncRes(const CallbackInfo& info) {
     Object recv = info[0].As<Object>();
     Function cb = info[1].As<Function>();
-    Object resource = info[2].As<Object>();
+    Value resource = info[2];
 
     TestWorkerWithUserDefRecv* worker = nullptr;
     if (resource == info.Env().Null()) {
       worker = new TestWorkerWithUserDefRecv(recv, cb, "TestResource");
     } else {
-      worker =
-          new TestWorkerWithUserDefRecv(recv, cb, "TestResource", resource);
+      worker = new TestWorkerWithUserDefRecv(
+          recv, cb, "TestResource", resource.As<Object>());
     }
 
     worker->Queue();

test/binding.gyp

@@ -106,7 +106,8 @@
     {
       'target_name': 'binding',
       'dependencies': ['../node_addon_api.gyp:node_addon_api_except'],
-      'sources': ['>@(build_sources)']
+      'sources': ['>@(build_sources)'],
+      'defines': ['NODE_ADDON_API_ENABLE_TYPE_CHECK_ON_AS']
     },
     {
       'target_name': 'binding_noexcept',

test/function.js

@@ -89,7 +89,7 @@ function test (binding) {
   assert.deepStrictEqual(args, [7, 8, 9]);
 
   assert.throws(() => {
-    binding.callWithInvalidReceiver();
+    binding.callWithInvalidReceiver(() => {});
   }, /Invalid (pointer passed as )?argument/);
 
   obj = binding.callConstructorWithArgs(testConstructor, 5, 6, 7);

test/globalObject/global_object_delete_property.cc

@@ -5,27 +5,27 @@ using namespace Napi;
 
 Value DeletePropertyWithCStyleStringAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  String key = info[0].As<String>();
+  String key = info[0].UnsafeAs<String>();
   return Boolean::New(
       info.Env(), MaybeUnwrap(globalObject.Delete(key.Utf8Value().c_str())));
 }
 
 Value DeletePropertyWithCppStyleStringAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  String key = info[0].As<String>();
+  String key = info[0].UnsafeAs<String>();
   return Boolean::New(info.Env(),
                       MaybeUnwrap(globalObject.Delete(key.Utf8Value())));
 }
 
 Value DeletePropertyWithInt32AsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  Number key = info[0].As<Number>();
+  Number key = info[0].UnsafeAs<Number>();
   return Boolean::New(info.Env(),
                       MaybeUnwrap(globalObject.Delete(key.Uint32Value())));
 }
 
 Value DeletePropertyWithNapiValueAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  Name key = info[0].As<Name>();
+  Name key = info[0].UnsafeAs<Name>();
   return Boolean::New(info.Env(), MaybeUnwrap(globalObject.Delete(key)));
 }

test/globalObject/global_object_get_property.cc

@@ -5,25 +5,25 @@ using namespace Napi;
 
 Value GetPropertyWithNapiValueAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  Name key = info[0].As<Name>();
+  Name key = info[0].UnsafeAs<Name>();
   return MaybeUnwrap(globalObject.Get(key));
 }
 
 Value GetPropertyWithInt32AsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  Number key = info[0].As<Napi::Number>();
+  Number key = info[0].UnsafeAs<Napi::Number>();
   return MaybeUnwrapOr(globalObject.Get(key.Uint32Value()), Value());
 }
 
 Value GetPropertyWithCStyleStringAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  String cStrkey = info[0].As<String>();
+  String cStrkey = info[0].UnsafeAs<String>();
   return MaybeUnwrapOr(globalObject.Get(cStrkey.Utf8Value().c_str()), Value());
 }
 
 Value GetPropertyWithCppStyleStringAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  String cppStrKey = info[0].As<String>();
+  String cppStrKey = info[0].UnsafeAs<String>();
   return MaybeUnwrapOr(globalObject.Get(cppStrKey.Utf8Value()), Value());
 }
 

test/globalObject/global_object_has_own_property.cc

@@ -5,7 +5,7 @@ using namespace Napi;
 
 Value HasPropertyWithCStyleStringAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  String key = info[0].As<String>();
+  String key = info[0].UnsafeAs<String>();
   return Boolean::New(
       info.Env(),
       MaybeUnwrapOr(globalObject.HasOwnProperty(key.Utf8Value().c_str()),
@@ -14,15 +14,15 @@ Value HasPropertyWithCStyleStringAsKey(const CallbackInfo& info) {
 
 Value HasPropertyWithCppStyleStringAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  String key = info[0].As<String>();
+  String key = info[0].UnsafeAs<String>();
   return Boolean::New(
       info.Env(),
       MaybeUnwrapOr(globalObject.HasOwnProperty(key.Utf8Value()), false));
 }
 
 Value HasPropertyWithNapiValueAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  Name key = info[0].As<Name>();
+  Name key = info[0].UnsafeAs<Name>();
   return Boolean::New(info.Env(),
                       MaybeUnwrap(globalObject.HasOwnProperty(key)));
 }

test/globalObject/global_object_set_property.cc

@@ -4,28 +4,28 @@ using namespace Napi;
 
 void SetPropertyWithCStyleStringAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  String key = info[0].As<String>();
+  String key = info[0].UnsafeAs<String>();
   Value value = info[1];
   globalObject.Set(key.Utf8Value().c_str(), value);
 }
 
 void SetPropertyWithCppStyleStringAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  String key = info[0].As<String>();
+  String key = info[0].UnsafeAs<String>();
   Value value = info[1];
   globalObject.Set(key.Utf8Value(), value);
 }
 
 void SetPropertyWithInt32AsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  Number key = info[0].As<Number>();
+  Number key = info[0].UnsafeAs<Number>();
   Value value = info[1];
   globalObject.Set(key.Uint32Value(), value);
 }
 
 void SetPropertyWithNapiValueAsKey(const CallbackInfo& info) {
   Object globalObject = info.Env().Global();
-  Name key = info[0].As<Name>();
+  Name key = info[0].UnsafeAs<Name>();
   Value value = info[1];
   globalObject.Set(key, value);
-}
+}

test/name.cc

@@ -21,19 +21,21 @@ Value EchoString(const CallbackInfo& info) {
 
 Value CreateString(const CallbackInfo& info) {
   String encoding = info[0].As<String>();
-  Number length = info[1].As<Number>();
+  Value length = info[1];
 
   if (encoding.Utf8Value() == "utf8") {
     if (length.IsUndefined()) {
       return String::New(info.Env(), testValueUtf8);
     } else {
-      return String::New(info.Env(), testValueUtf8, length.Uint32Value());
+      return String::New(
+          info.Env(), testValueUtf8, length.As<Number>().Uint32Value());
     }
   } else if (encoding.Utf8Value() == "utf16") {
     if (length.IsUndefined()) {
       return String::New(info.Env(), testValueUtf16);
     } else {
-      return String::New(info.Env(), testValueUtf16, length.Uint32Value());
+      return String::New(
+          info.Env(), testValueUtf16, length.As<Number>().Uint32Value());
     }
   } else {
     Error::New(info.Env(), "Invalid encoding.").ThrowAsJavaScriptException();
@@ -44,20 +46,20 @@ Value CreateString(const CallbackInfo& info) {
 Value CheckString(const CallbackInfo& info) {
   String value = info[0].As<String>();
   String encoding = info[1].As<String>();
-  Number length = info[2].As<Number>();
+  Value length = info[2];
 
   if (encoding.Utf8Value() == "utf8") {
     std::string testValue = testValueUtf8;
     if (!length.IsUndefined()) {
-      testValue = testValue.substr(0, length.Uint32Value());
+      testValue = testValue.substr(0, length.As<Number>().Uint32Value());
     }
 
     std::string stringValue = value;
     return Boolean::New(info.Env(), stringValue == testValue);
   } else if (encoding.Utf8Value() == "utf16") {
     std::u16string testValue = testValueUtf16;
     if (!length.IsUndefined()) {
-      testValue = testValue.substr(0, length.Uint32Value());
+      testValue = testValue.substr(0, length.As<Number>().Uint32Value());
     }
 
     std::u16string stringValue = value;
@@ -69,10 +71,10 @@ Value CheckString(const CallbackInfo& info) {
 }
 
 Value CreateSymbol(const CallbackInfo& info) {
-  String description = info[0].As<String>();
+  Value description = info[0];
 
   if (!description.IsUndefined()) {
-    return Symbol::New(info.Env(), description);
+    return Symbol::New(info.Env(), description.As<String>());
   } else {
     return Symbol::New(info.Env());
   }

test/object/delete_property.cc

@@ -4,34 +4,34 @@
 using namespace Napi;
 
 Value DeletePropertyWithUint32(const CallbackInfo& info) {
-  Object obj = info[0].As<Object>();
+  Object obj = info[0].UnsafeAs<Object>();
   Number key = info[1].As<Number>();
   return Boolean::New(info.Env(), MaybeUnwrap(obj.Delete(key.Uint32Value())));
 }
 
 Value DeletePropertyWithNapiValue(const CallbackInfo& info) {
-  Object obj = info[0].As<Object>();
+  Object obj = info[0].UnsafeAs<Object>();
   Name key = info[1].As<Name>();
   return Boolean::New(
       info.Env(),
       MaybeUnwrapOr(obj.Delete(static_cast<napi_value>(key)), false));
 }
 
 Value DeletePropertyWithNapiWrapperValue(const CallbackInfo& info) {
-  Object obj = info[0].As<Object>();
+  Object obj = info[0].UnsafeAs<Object>();
   Name key = info[1].As<Name>();
   return Boolean::New(info.Env(), MaybeUnwrapOr(obj.Delete(key), false));
 }
 
 Value DeletePropertyWithCStyleString(const CallbackInfo& info) {
-  Object obj = info[0].As<Object>();
+  Object obj = info[0].UnsafeAs<Object>();
   String jsKey = info[1].As<String>();
   return Boolean::New(
       info.Env(), MaybeUnwrapOr(obj.Delete(jsKey.Utf8Value().c_str()), false));
 }
 
 Value DeletePropertyWithCppStyleString(const CallbackInfo& info) {
-  Object obj = info[0].As<Object>();
+  Object obj = info[0].UnsafeAs<Object>();
   String jsKey = info[1].As<String>();
   return Boolean::New(info.Env(),
                       MaybeUnwrapOr(obj.Delete(jsKey.Utf8Value()), false));

test/object/get_property.cc

@@ -4,31 +4,31 @@
 using namespace Napi;
 
 Value GetPropertyWithNapiValue(const CallbackInfo& info) {
-  Object obj = info[0].As<Object>();
+  Object obj = info[0].UnsafeAs<Object>();
   Name key = info[1].As<Name>();
   return MaybeUnwrapOr(obj.Get(static_cast<napi_value>(key)), Value());
 }
 
 Value GetPropertyWithNapiWrapperValue(const CallbackInfo& info) {
-  Object obj = info[0].As<Object>();
+  Object obj = info[0].UnsafeAs<Object>();
   Name key = info[1].As<Name>();
   return MaybeUnwrapOr(obj.Get(key), Value());
 }
 
 Value GetPropertyWithUint32(const CallbackInfo& info) {
-  Object obj = info[0].As<Object>();
+  Object obj = info[0].UnsafeAs<Object>();
   Number key = info[1].As<Number>();
   return MaybeUnwrap(obj.Get(key.Uint32Value()));
 }
 
 Value GetPropertyWithCStyleString(const CallbackInfo& info) {
-  Object obj = info[0].As<Object>();
+  Object obj = info[0].UnsafeAs<Object>();
   String jsKey = info[1].As<String>();
   return MaybeUnwrapOr(obj.Get(jsKey.Utf8Value().c_str()), Value());
 }
 
 Value GetPropertyWithCppStyleString(const CallbackInfo& info) {
-  Object obj = info[0].As<Object>();
+  Object obj = info[0].UnsafeAs<Object>();
   String jsKey = info[1].As<String>();
   return MaybeUnwrapOr(obj.Get(jsKey.Utf8Value()), Value());
 }