Add missing descriptor methods in dataclasses and functools (#7203)

Author: AlexWaygood

stdlib/dataclasses.pyi

@@ -111,6 +111,8 @@ class Field(Generic[_T]):
             compare: bool,
             metadata: Mapping[Any, Any],
         ) -> None: ...
+
+    def __set_name__(self, owner: Type[Any], name: str) -> None: ...
     if sys.version_info >= (3, 9):
         def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 

stdlib/functools.pyi

@@ -69,7 +69,11 @@ class partialmethod(Generic[_T]):
     def __init__(self, __func: Callable[..., _T], *args: Any, **keywords: Any) -> None: ...
     @overload
     def __init__(self, __func: _Descriptor, *args: Any, **keywords: Any) -> None: ...
-    def __get__(self, obj: Any, cls: type[Any]) -> Callable[..., _T]: ...
+    if sys.version_info >= (3, 8):
+        def __get__(self, obj: Any, cls: type[Any] | None = ...) -> Callable[..., _T]: ...
+    else:
+        def __get__(self, obj: Any, cls: type[Any] | None) -> Callable[..., _T]: ...
+
     @property
     def __isabstractmethod__(self) -> bool: ...
     if sys.version_info >= (3, 9):
@@ -107,7 +111,7 @@ if sys.version_info >= (3, 8):
         def register(self, cls: Callable[..., _T], method: None = ...) -> Callable[..., _T]: ...
         @overload
         def register(self, cls: type[Any], method: Callable[..., _T]) -> Callable[..., _T]: ...
-        def __call__(self, *args: Any, **kwargs: Any) -> _T: ...
+        def __get__(self, obj: _S, cls: type[_S] | None = ...) -> Callable[..., _T]: ...
 
     class cached_property(Generic[_T]):
         func: Callable[[Any], _T]

tests/stubtest_allowlists/py310.txt

@@ -50,8 +50,6 @@ dataclasses.KW_ONLY
 enum.Enum._generate_next_value_
 fractions.Fraction.__new__  # overload is too complicated for stubtest to resolve
 ftplib.FTP.trust_server_pasv_ipv4_address  # Dangerous to use, intentionally undocumented, intentionally missing from typeshed. #6154
-functools.partialmethod.__get__
-functools.singledispatchmethod.__call__
 gettext.install
 gettext.translation
 hashlib.sha3_\d+  # Can be a class or a built-in function

tests/stubtest_allowlists/py38.txt

@@ -37,8 +37,6 @@ dummy_threading.local.__new__
 enum.Enum._generate_next_value_
 fractions.Fraction.__new__  # overload is too complicated for stubtest to resolve
 ftplib.FTP.trust_server_pasv_ipv4_address  # Dangerous to use, intentionally undocumented, intentionally missing from typeshed. #6154
-functools.partialmethod.__get__
-functools.singledispatchmethod.__call__  # A lie to reflect that the descriptor get returns a callable
 gettext.install  # codeset default value is ['unspecified'] so can't be specified
 gettext.translation  # codeset default value is ['unspecified'] so can't be specified
 hmac.new  # Stub is a white lie; see comments in the stub

tests/stubtest_allowlists/py39.txt

@@ -36,8 +36,6 @@ dataclasses.field
 enum.Enum._generate_next_value_
 fractions.Fraction.__new__  # overload is too complicated for stubtest to resolve
 ftplib.FTP.trust_server_pasv_ipv4_address  # Dangerous to use, intentionally undocumented, intentionally missing from typeshed. #6154
-functools.partialmethod.__get__
-functools.singledispatchmethod.__call__
 gettext.install
 gettext.translation
 hashlib.sha3_\d+