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Abstract(Async)ContextManager.__enter__ return type defaults to Self #13951

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Abstract(Async)ContextManager.__enter__ return type defaults to Self #13951

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fbb3258
Abstract(Async)ContextManager.__enter__ return type defaults to Self
srittau May 6, 2025
9a36045
Add a test case
srittau May 6, 2025
683ba60
[pre-commit.ci] auto fixes from pre-commit.com hooks
pre-commit-ci[bot] May 6, 2025
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11 changes: 10 additions & 1 deletion stdlib/@tests/test_cases/check_contextlib.py
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Original file line number Diff line number Diff line change
@@ -1,9 +1,18 @@
from __future__ import annotations

from contextlib import ExitStack
from contextlib import AbstractContextManager, ExitStack
from typing_extensions import assert_type


class CM1(AbstractContextManager):
def __exit__(self, *args) -> None:
return None


with CM1() as cm1:
assert_type(cm1, CM1)


# See issue #7961
class Thing(ExitStack):
pass
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9 changes: 5 additions & 4 deletions stdlib/contextlib.pyi
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Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@
_T = TypeVar("_T")
_T_co = TypeVar("_T_co", covariant=True)
_T_io = TypeVar("_T_io", bound=IO[str] | None)
_EnterT_co = TypeVar("_EnterT_co", covariant=True, default=Self)

Check failure on line 34 in stdlib/contextlib.pyi

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GitHub Actions / pyright: Run test cases (Linux, 3.13) 

"Self" is not valid in this context (reportGeneralTypeIssues)
_ExitT_co = TypeVar("_ExitT_co", covariant=True, bound=bool | None, default=bool | None)
_F = TypeVar("_F", bound=Callable[..., Any])
_G_co = TypeVar("_G_co", bound=Generator[Any, Any, Any] | AsyncGenerator[Any, Any], covariant=True)
Expand All @@ -46,8 +47,8 @@
# At runtime it inherits from ABC and is not a Protocol, but it is on the
# allowlist for use as a Protocol.
@runtime_checkable
class AbstractContextManager(ABC, Protocol[_T_co, _ExitT_co]): # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
def __enter__(self) -> _T_co: ...
class AbstractContextManager(ABC, Protocol[_EnterT_co, _ExitT_co]): # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
def __enter__(self) -> _EnterT_co: ...
@abstractmethod
def __exit__(
self, exc_type: type[BaseException] | None, exc_value: BaseException | None, traceback: TracebackType | None, /
Expand All @@ -57,8 +58,8 @@
# At runtime it inherits from ABC and is not a Protocol, but it is on the
# allowlist for use as a Protocol.
@runtime_checkable
class AbstractAsyncContextManager(ABC, Protocol[_T_co, _ExitT_co]): # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
async def __aenter__(self) -> _T_co: ...
class AbstractAsyncContextManager(ABC, Protocol[_EnterT_co, _ExitT_co]): # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
async def __aenter__(self) -> _EnterT_co: ...
@abstractmethod
async def __aexit__(
self, exc_type: type[BaseException] | None, exc_value: BaseException | None, traceback: TracebackType | None, /
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