Fixed TypeError on check_type(..., None)

docs/versionhistory.rst

@@ -7,6 +7,7 @@ This library adheres to `Semantic Versioning 2.0 <https://semver.org/#semantic-v
 
 - Fixed ``warn_on_error()`` not showing where the type violation actually occurred
 - Fixed local assignment to ``*args`` or ``**kwargs`` being type checked incorrectly
+- Fixed ``TypeError`` on ``check_type(..., None)``
 
 **3.0.1** (2023-03-16)
 

src/typeguard/_checkers.py

@@ -530,6 +530,13 @@ def check_typeguard(
     check_type_internal(value, bool, memo)
 
 
+def check_none(
+    value: Any, origin_type: Any, args: tuple[Any, ...], memo: TypeCheckMemo
+) -> None:
+    if value is not None:
+        raise TypeCheckError("is not None")
+
+
 def check_number(
     value: Any, origin_type: Any, args: tuple[Any, ...], memo: TypeCheckMemo
 ) -> None:
@@ -689,6 +696,7 @@ def check_type_internal(value: Any, annotation: Any, memo: TypeCheckMemo) -> Non
     LiteralString: check_literal_string,
     Mapping: check_mapping,
     MutableMapping: check_mapping,
+    None: check_none,
     collections.abc.Mapping: check_mapping,
     collections.abc.MutableMapping: check_mapping,
     Self: check_self,

tests/test_checkers.py

@@ -999,6 +999,10 @@ class Foo(SubclassableAny):
     check_type(Foo(), int)
 
 
+def test_none():
+    check_type(None, None)
+
+
 def test_return_checked_value():
     value = {"foo": 1}
     assert check_type(value, Dict[str, int]) is value