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Remove unnecessary error message for match class patterns #19708

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Merged
merged 1 commit into from
Aug 23, 2025
Merged

Remove unnecessary error message for match class patterns #19708

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8 changes: 4 additions & 4 deletions mypy/checkpattern.py
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Original file line number Diff line number Diff line change
Expand Up @@ -539,12 +539,12 @@ def visit_class_pattern(self, o: ClassPattern) -> PatternType:
#
type_info = o.class_ref.node
if type_info is None:
return PatternType(AnyType(TypeOfAny.from_error), AnyType(TypeOfAny.from_error), {})
if isinstance(type_info, TypeAlias) and not type_info.no_args:
typ: Type = AnyType(TypeOfAny.from_error)
elif isinstance(type_info, TypeAlias) and not type_info.no_args:
self.msg.fail(message_registry.CLASS_PATTERN_GENERIC_TYPE_ALIAS, o)
return self.early_non_match()
if isinstance(type_info, TypeInfo):
typ: Type = fill_typevars_with_any(type_info)
elif isinstance(type_info, TypeInfo):
typ = fill_typevars_with_any(type_info)
elif isinstance(type_info, TypeAlias):
typ = type_info.target
elif (
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9 changes: 5 additions & 4 deletions test-data/unit/check-python310.test
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Expand Up @@ -721,13 +721,14 @@ m: object
match m:
case xyz(y): # E: Name "xyz" is not defined
reveal_type(m) # N: Revealed type is "Any"
reveal_type(y) # E: Cannot determine type of "y" \
# N: Revealed type is "Any"
reveal_type(y) # N: Revealed type is "Any"

match m:
case xyz(z=x): # E: Name "xyz" is not defined
reveal_type(x) # E: Cannot determine type of "x" \
# N: Revealed type is "Any"
reveal_type(x) # N: Revealed type is "Any"
case (xyz1() as n) | (xyz2(attr=n)): # E: Name "xyz1" is not defined \
# E: Name "xyz2" is not defined
reveal_type(n) # N: Revealed type is "Any"

[case testMatchClassPatternCaptureDataclass]
from dataclasses import dataclass
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