mercurial/typelib.py

typing: add type hints to mercurial/win32.py

These are the low level functions that are imported by the mercurial.windows
module, which is in turn imported by mercurial.utils as the platform module.
Pretty straightforward, but pytype inferred very little of it, likely because of
the heavy ctypes usage.  It also seems to trigger a pytype bug in procutil, now
that it has an idea of the underlying function type, so disable that warning to
maintain a working test.

# typelib.py - type hint aliases and support
#
# Copyright 2022 Matt Harbison <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import typing

# Note: this is slightly different from pycompat.TYPE_CHECKING, as using
# pycompat causes the BinaryIO_Proxy type to be resolved to ``object`` when
# used as the base class during a pytype run.
TYPE_CHECKING = typing.TYPE_CHECKING


# The BinaryIO class provides empty methods, which at runtime means that
# ``__getattr__`` on the proxy classes won't get called for the methods that
# should delegate to the internal object.  So to avoid runtime changes because
# of the required typing inheritance, just use BinaryIO when typechecking, and
# ``object`` otherwise.
if TYPE_CHECKING:
    from typing import (
        BinaryIO,
    )

    BinaryIO_Proxy = BinaryIO
else:
    BinaryIO_Proxy = object