From 2b510d667afe7f900c238f57fd0e0c71a54c74f2 Mon Sep 17 00:00:00 2001
From: Enrique Gonzalez Paredes <enriqueg@cscs.ch>
Date: Tue, 9 Jan 2024 17:52:51 +0100
Subject: [PATCH] Fix bug in the special casing of `typing.Any` as a type.

---
 src/gt4py/eve/extended_typing.py                   | 8 ++++----
 src/gt4py/eve/type_validation.py                   | 2 --
 tests/eve_tests/unit_tests/test_type_validation.py | 5 +++--
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/gt4py/eve/extended_typing.py b/src/gt4py/eve/extended_typing.py
index 17462a37ff..7bbf7c459b 100644
--- a/src/gt4py/eve/extended_typing.py
+++ b/src/gt4py/eve/extended_typing.py
@@ -493,7 +493,7 @@ def _patched_proto_hook(other):  # type: ignore[no-untyped-def]
     if isinstance(_typing.Any, type):  # Python >= 3.11
         _ArtefactTypes = (*_ArtefactTypes, _typing.Any)
 
-# `Any` is a class since typing_extensions >= 4.4
+# `Any` is a class since typing_extensions >= 4.4 and Python 3.11
 if (typing_exts_any := getattr(_typing_extensions, "Any", None)) is not _typing.Any and isinstance(
     typing_exts_any, type
 ):
@@ -504,11 +504,11 @@ def is_actual_type(obj: Any) -> TypeGuard[Type]:
     """Check if an object has an actual type and instead of a typing artefact like ``GenericAlias`` or ``Any``.
 
     This is needed because since Python 3.9:
-        ``isinstance(types.GenericAlias(),  type) is True``
+        ``isinstance(types.GenericAlias(), type) is True``
     and since Python 3.11:
-        ``isinstance(typing.Any,  type) is True``
+        ``isinstance(typing.Any, type) is True``
     """
-    return isinstance(obj, type) and type(obj) not in _ArtefactTypes
+    return isinstance(obj, type) and obj not in _ArtefactTypes
 
 
 if hasattr(_typing_extensions, "Any") and _typing.Any is not _typing_extensions.Any:  # type: ignore[attr-defined] # _typing_extensions.Any only from >= 4.4
diff --git a/src/gt4py/eve/type_validation.py b/src/gt4py/eve/type_validation.py
index 2116969587..65f492ebfe 100644
--- a/src/gt4py/eve/type_validation.py
+++ b/src/gt4py/eve/type_validation.py
@@ -358,8 +358,6 @@ def make_is_instance_of(name: str, type_: type) -> FixedTypeValidator:
         """Create an ``FixedTypeValidator`` validator for a specific type."""
 
         def _is_instance_of(value: Any, **kwargs: Any) -> None:
-            if type_ is Any:
-                return
             if not isinstance(value, type_):
                 raise TypeError(
                     f"'{name}' must be {type_} (got '{value}' which is a {type(value)})."
diff --git a/tests/eve_tests/unit_tests/test_type_validation.py b/tests/eve_tests/unit_tests/test_type_validation.py
index 70ef033ff0..d9977f0d3a 100644
--- a/tests/eve_tests/unit_tests/test_type_validation.py
+++ b/tests/eve_tests/unit_tests/test_type_validation.py
@@ -28,6 +28,7 @@
 )
 from gt4py.eve.extended_typing import (
     Any,
+    Callable,
     Dict,
     Final,
     ForwardRef,
@@ -41,8 +42,8 @@
 )
 
 
-VALIDATORS: Final = [type_val.simple_type_validator]
-FACTORIES: Final = [type_val.simple_type_validator_factory]
+VALIDATORS: Final[list[Callable]] = [type_val.simple_type_validator]
+FACTORIES: Final[list[Callable]] = [type_val.simple_type_validator_factory]
 
 
 class SampleEnum(enum.Enum):