Unpack invalid Concatenate correctly

Author: Daraan

src/test_typing_extensions.py

@@ -7339,9 +7339,7 @@ def test_invalid_cases(self):
 
         # Test with Concatenate
         callable_concat = CallableP[Concatenate[Any, T2, P], Any]
-        reveal_type(callable_concat)
         self.assertEqual(callable_concat.__parameters__, (T2, P))
-        self.assertEqual(get_args(callable_concat), (Concatenate[Any, T2, P], Any))
 
         # TypeVarTuple
         Ts = TypeVarTuple("Ts")
@@ -7359,6 +7357,15 @@ def test_invalid_cases(self):
         invalud_tuple_C = Variadic[[int, T]]
         self.assertEqual(invalud_tuple_C.__parameters__, ())
         self.assertEqual(get_args(invalud_tuple_C), ([int, T],))
+        
+    @skipUnless(TYPING_3_11_0, "Concatenate not unpacked anymore")
+    def test_further_invalid_cases(self):
+        P = ParamSpec('P')
+        T = TypeVar("T")
+        T2 = TypeVar("T2")
+        CallableP = TypeAliasType("CallableP", Callable[P, T], type_params=(P,))
+        callable_concat = CallableP[Concatenate[Any, T2, P], Any]
+        self.assertEqual(get_args(callable_concat), (Concatenate[Any, T2, P], Any))
 
     def test_pickle(self):
         global Alias

src/typing_extensions.py

@@ -3543,15 +3543,10 @@ def __getitem__(self, parameters):
         else:
             def _check_parameter(self, item, typ=_marker):
                 # Allow [], [int], [int, str], [int, ...], [int, T]
-                if isinstance(item, _UnpackAlias):
-                    args = (
-                        item.__args__ # e.g. (int, str)
-                        if sys.version_info[:2] >= (3, 9)
-                        else item.__args__  # (typing.Tuple[int, float],)
-                    )
+                if isinstance(item, (_UnpackAlias, _ConcatenateGenericAlias)):
                     # Unpack
                     yield from [checked
-                                for arg in args
+                                for arg in item.__args__
                                 for checked in self._check_parameter(arg)]
                 elif item is ...:
                     yield ...
@@ -3578,7 +3573,12 @@ def __getitem__(self, parameters):
                         for item, typ in zip(parameters, type_params)
                         for checked in self._check_parameter(item, typ)
                 ]
-                alias = typing._GenericAlias(self, tuple(parameters))
+                if sys.version_info[:2] == (3, 10):
+                    alias = typing._GenericAlias(self, tuple(parameters),
+                                                 _typevar_types=(TypeVar, ParamSpec)
+                                                 )
+                else:
+                    alias = typing._GenericAlias(self, tuple(parameters))
                 alias.__name__ = self.__name__
                 alias.__value__ = self.__value__
                 alias.__type_params__ = self.__type_params__