Migrate to typing.dataclass_transform()

[superbobry]

attrs type stubs seem to use a non-standard pyright extension instead of the API described in PEP-681:

attrs/src/attr/__init__.pyi

Lines 106 to 121 in 4461e2c

	# Static type inference support via __dataclass_transform__ implemented as per:
	# https:/microsoft/pyright/blob/1.1.135/specs/dataclass_transforms.md
	# This annotation must be applied to all overloads of "define" and "attrs"
	#
	# NOTE: This is a typing construct and does not exist at runtime. Extensions
	# wrapping attrs decorators should declare a separate __dataclass_transform__
	# signature in the extension module using the specification linked above to
	# provide pyright support.
	def __dataclass_transform__(
	*,
	eq_default: bool = True,
	order_default: bool = False,
	kw_only_default: bool = False,
	frozen_default: bool = False,
	field_descriptors: Tuple[Union[type, Callable[..., Any]], ...] = (()),
	) -> Callable[[_T], _T]: ...

This makes it difficult for other type checkers and similar tools to consume these type stubs without mirroring the pyright extension.

Would you accept a PR replacing all usages of __dataclass_transform__() with typing.dataclass_transform()? We can use typing_extensions to get dataclass_transform() on Python < 3.11.

[Tinche]

Don't see why not, feel free to proceed with a PR. I believe our use of dataclass_transform predates the PEP and the typing implementation.

[superbobry]

Yes, IIRC that feature was incubated in pyright and then proposed&accepted as a PEP. Will send a PR soon.

[hynek]

fixed by #1158