Enable flake8-pyi's Y034 check in stdlib/typing.pyi (#8530)

Author: AlexWaygood

.flake8

@@ -18,9 +18,6 @@
 #       F405 defined from star imports
 
 # Rules that we'd like to enable in the future:
-#       Y034 Detect common errors where certain methods are annotated as having a fixed
-#            return type, despite returning self at runtime (temporarily disabled for
-#            typing.pyi, enabled elsewhere).
 #       Y037 Use PEP 604 syntax instead of `typing.Union` and `typing.Optional`.
 #            Currently can't be enabled due to a few lingering bugs in mypy regarding
 #            PEP 604 type aliases (see #4819).
@@ -33,6 +30,6 @@ per-file-ignores =
   # Unfortunately, flake8 does not allow to "noqa" just a specific error inside the file itself.
   # https://github.com/PyCQA/flake8/issues/1079
   #     F811 redefinition of unused '...'
-  stdlib/typing.pyi: E301, E302, E305, E501, E701, E741, F401, F403, F405, F811, F822, Y034, Y037
+  stdlib/typing.pyi: E301, E302, E305, E501, E701, E741, F401, F403, F405, F811, F822, Y037
 
 exclude = .venv*,.git,*_pb2.pyi

stdlib/typing.pyi

@@ -1,6 +1,7 @@
+import _typeshed
 import collections  # Needed by aliases like DefaultDict, see mypy issue 2986
 import sys
-from _typeshed import IdentityFunction, Incomplete, Self as TypeshedSelf, SupportsKeysAndGetItem
+from _typeshed import IdentityFunction, Incomplete, SupportsKeysAndGetItem
 from abc import ABCMeta, abstractmethod
 from contextlib import AbstractAsyncContextManager, AbstractContextManager
 from re import Match as Match, Pattern as Pattern
@@ -496,7 +497,7 @@ class MutableSequence(Sequence[_T], Generic[_T]):
     def reverse(self) -> None: ...
     def pop(self, index: int = ...) -> _T: ...
     def remove(self, value: _T) -> None: ...
-    def __iadd__(self: TypeshedSelf, values: Iterable[_T]) -> TypeshedSelf: ...
+    def __iadd__(self: _typeshed.Self, values: Iterable[_T]) -> _typeshed.Self: ...
 
 class AbstractSet(Collection[_T_co], Generic[_T_co]):
     @abstractmethod
@@ -522,10 +523,10 @@ class MutableSet(AbstractSet[_T], Generic[_T]):
     def clear(self) -> None: ...
     def pop(self) -> _T: ...
     def remove(self, value: _T) -> None: ...
-    def __ior__(self: TypeshedSelf, it: AbstractSet[_T]) -> TypeshedSelf: ...  # type: ignore[override,misc]
-    def __iand__(self: TypeshedSelf, it: AbstractSet[Any]) -> TypeshedSelf: ...
-    def __ixor__(self: TypeshedSelf, it: AbstractSet[_T]) -> TypeshedSelf: ...  # type: ignore[override,misc]
-    def __isub__(self: TypeshedSelf, it: AbstractSet[Any]) -> TypeshedSelf: ...
+    def __ior__(self: _typeshed.Self, it: AbstractSet[_T]) -> _typeshed.Self: ...  # type: ignore[override,misc]
+    def __iand__(self: _typeshed.Self, it: AbstractSet[Any]) -> _typeshed.Self: ...
+    def __ixor__(self: _typeshed.Self, it: AbstractSet[_T]) -> _typeshed.Self: ...  # type: ignore[override,misc]
+    def __isub__(self: _typeshed.Self, it: AbstractSet[Any]) -> _typeshed.Self: ...
 
 class MappingView(Sized):
     def __init__(self, mapping: Mapping[Any, Any]) -> None: ...  # undocumented
@@ -778,7 +779,7 @@ class NamedTuple(tuple[Any, ...]):
     else:
         def _asdict(self) -> collections.OrderedDict[str, Any]: ...
 
-    def _replace(self: TypeshedSelf, **kwargs: Any) -> TypeshedSelf: ...
+    def _replace(self: _typeshed.Self, **kwargs: Any) -> _typeshed.Self: ...
 
 # Internal mypy fallback type for all typed dicts (does not exist at runtime)
 # N.B. Keep this mostly in sync with typing_extensions._TypedDict/mypy_extensions._TypedDict
@@ -788,7 +789,7 @@ class _TypedDict(Mapping[str, object], metaclass=ABCMeta):
     if sys.version_info >= (3, 9):
         __required_keys__: ClassVar[frozenset[str]]
         __optional_keys__: ClassVar[frozenset[str]]
-    def copy(self: TypeshedSelf) -> TypeshedSelf: ...
+    def copy(self: _typeshed.Self) -> _typeshed.Self: ...
     # Using NoReturn so that only calls using mypy plugin hook that specialize the signature
     # can go through.
     def setdefault(self, k: NoReturn, default: object) -> object: ...
@@ -800,8 +801,8 @@ class _TypedDict(Mapping[str, object], metaclass=ABCMeta):
     def keys(self) -> KeysView[str]: ...
     def values(self) -> ValuesView[object]: ...
     if sys.version_info >= (3, 9):
-        def __or__(self: TypeshedSelf, __value: TypeshedSelf) -> TypeshedSelf: ...
-        def __ior__(self: TypeshedSelf, __value: TypeshedSelf) -> TypeshedSelf: ...
+        def __or__(self: _typeshed.Self, __value: _typeshed.Self) -> _typeshed.Self: ...
+        def __ior__(self: _typeshed.Self, __value: _typeshed.Self) -> _typeshed.Self: ...
 
 @_final
 class ForwardRef: