mercurial/typelib.py

pytype: stop excluding mercurial/ui.py

ui.extractchoices() is perhaps making assumptions that it shouldn't about the
pattern always matching, but presumably we have test coverage for that.

PyCharm flags the updated classes with a warning "Class xxx must implement all
abstract methods", and suggests adding `abc.ABC` to the superclasses.  I'm not
sure why, unless it doesn't recognize the `__getattr__()` delegation pattern.
Additionally, we can't unconditionally subclass `typing.BinaryIO` because that
defeats the `__getattr__` delegation to the wrapped object at runtime.  Instead,
it has to only subclass during the type checking phase[1].

In any event, this fixes:

    File "/mnt/c/Users/Matt/hg/mercurial/ui.py", line 1518, in _runpager:
        Function subprocess.Popen.__new__ was called with the wrong arguments [wrong-arg-types]
             Expected: (cls, args, bufsize, executable, stdin,
                        stdout: Optional[Union[IO, int]] = ..., ...)
      Actually passed: (cls, args, bufsize, stdin,
                        stdout: Union[mercurial.utils.procutil.WriteAllWrapper,
                                mercurial.windows.winstdout], ...)
    File "/mnt/c/Users/Matt/hg/mercurial/ui.py", line 1798, in extractchoices:
        No attribute 'group' on None [attribute-error]
      In Optional[Match[bytes]]
    File "/mnt/c/Users/Matt/hg/mercurial/ui.py", line 1799, in extractchoices:
        No attribute 'group' on None [attribute-error]
      In Optional[Match[bytes]]

[1] https://stackoverflow.com/q/71365594

# 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