Add provisional support for PEP 702 (marking classes and functions as deprecated)

[erictraut]

See https://peps.python.org/pep-0702/ for details.

[erictraut]

This will be included in the next release.

Note: @JelleZijlstra

[erictraut]

This feature includes a new diagnostic rule called reportDeprecated. It's off by default but on in strict mode. If disabled, deprecated symbol usage is displayed in VS Code using a strike-through appearance (using a diagnostic hint).

[JelleZijlstra]

Thanks as always for your fast work! Let me know if the implementation leads to any feedback about the PEP. I will also amend the PEP to note the pyright implementation.

[erictraut]

Oh, I forgot to mention that this feature will not work at runtime until the deprecated symbol is added to typing_extensions. As a temporary workaround, I've defined deprecated in the typing_extensions.pyi stub that is bundled with pyright.

[erictraut]

This is included in pyright 1.1.289, which I just published. It will also be included in a future release of pylance.

[FeeeeK]

Maybe I don't understand something, but it doesn't seem to work for overloads of __init__ in classes:

but works for function overloads

[erictraut]

@FeeeeK, this was an oversight. The implementation doesn't currently handle deprecated constructors. This will be addressed in the next release.

[finite-state-machine]

@FeeeeK, this was an oversight. The implementation doesn't currently handle deprecated constructors. This will be addressed in the next release.

@erictraut It looks like 1.1.373 supports deprecated __init__() @overloads 🎉, but there appear to be issues with __new__() and @overloads.

pyright-play.net

from __future__ import annotations

# pyright: strict

from typing import (
        Union,
        overload,
        )

from typing_extensions import (
        Self,
        deprecated,
        )


class ClassWithInit:

    @overload
    def __init__(self, value: int, /) -> None: ...
    @deprecated("passing strings is deprecated")
    @overload
    def __init__(self, value: str, /) -> None: ...

    def __init__(self, value: Union[int, str], /) -> None:
        pass

class ClassWithNew:

    @overload
    def __new__(cls, value: int, /) -> Self: ...
    @deprecated("passing strings is deprecated")
    @overload
    def __new__(cls, value: str, /) -> Self: ...

    def __new__(cls, value: Union[int, str], /) -> Self:
        return super().__new__(cls)


ClassWithInit(42)           # no error, as expected
ClassWithInit('forty-two')  # "The constructor for class "ClassWithInit" is deprecated"
ClassWithNew(42)            # no error, as expected
ClassWithNew('forty-two')   # no error (expected: similar error to above)

[erictraut]

Could you please file a new bug so this doesn't get lost?

[finite-state-machine]

Could you please file a new bug so this doesn't get lost?

Hopefully this will do the trick: #8574