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Allow types.NoneType in match cases #20383

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Merged
ilevkivskyi merged 1 commit into from
Dec 9, 2025
Merged

Allow types.NoneType in match cases #20383

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Allow NoneType in match cases
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@A5rocks
A5rocks committed Dec 9, 2025
commit ef53130b0fcc786804a9a7e3d6211a98828b62e6
3 changes: 3 additions & 0 deletions mypy/checkpattern.py
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Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,7 @@
Type,
TypedDictType,
TypeOfAny,
TypeType,
TypeVarTupleType,
TypeVarType,
UninhabitedType,
Expand Down Expand Up @@ -556,6 +557,8 @@ def visit_class_pattern(self, o: ClassPattern) -> PatternType:
fallback = self.chk.named_type("builtins.function")
any_type = AnyType(TypeOfAny.unannotated)
typ = callable_with_ellipsis(any_type, ret_type=any_type, fallback=fallback)
elif isinstance(p_typ, TypeType) and isinstance(p_typ.item, NoneType):
typ = p_typ.item
elif not isinstance(p_typ, AnyType):
self.msg.fail(
message_registry.CLASS_PATTERN_TYPE_REQUIRED.format(
Expand Down
16 changes: 16 additions & 0 deletions test-data/unit/check-python310.test
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Expand Up @@ -3178,3 +3178,19 @@ match 5:
reveal_type(b) # N: Revealed type is "Any"
case BlahBlah(c=c): # E: Name "BlahBlah" is not defined
reveal_type(c) # N: Revealed type is "Any"

[case testMatchAllowsNoneTypeAsClass]
import types

class V:
X = types.NoneType

def fun(val: str | None):
match val:
case V.X():
reveal_type(val) # N: Revealed type is "None"

match val:
case types.NoneType():
reveal_type(val) # N: Revealed type is "None"
[builtins fixtures/tuple.pyi]