Skip to content

fix: prevent crash on dataclass with PEP695 TypeVarTuple on py3.13 #19565

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Aug 2, 2025
Merged

fix: prevent crash on dataclass with PEP695 TypeVarTuple on py3.13 #19565

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
66bf1a0
Fix Instance creation
sterliakov Aug 1, 2025
12f892c
Move testcase to 3.12+
sterliakov Aug 1, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 1 addition & 2 deletions mypy/plugins/dataclasses.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -410,13 +410,12 @@ def _add_dunder_replace(self, attributes: list[DataclassAttribute]) -> None:
for attr in attributes
if attr.is_in_init
]
type_vars = [tv for tv in self._cls.type_vars]
add_method_to_class(
self._api,
self._cls,
"__replace__",
args=args,
return_type=Instance(self._cls.info, type_vars),
return_type=fill_typevars(self._cls.info),
)

def _add_internal_replace_method(self, attributes: list[DataclassAttribute]) -> None:
Expand Down
11 changes: 11 additions & 0 deletions test-data/unit/check-dataclasses.test
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2682,3 +2682,14 @@ class ClassB(ClassA):
def value(self) -> int: # E: Name "value" already defined on line 10
return 0
[builtins fixtures/dict.pyi]

[case testDataclassWithTypeVarTuple]
# flags: --python-version 3.13
# https://github.com/python/mypy/issues/19559
from typing import Callable
from dataclasses import dataclass

@dataclass
class Test[*Ts, R]:
a: Callable[[*Ts], R]
[builtins fixtures/dict.pyi]
Loading