Click 8.0 does not support mypy's no_implicit_reexport

[tucked]

Looks like 8.0.0 started shipping type annotations (yay!): 0103c95

Something doesn't seem to be clicking (no pun intended 😁) with mypy , though:

error: Name 'click.Context' is not defined
error: Name 'click.Option' is not defined
error: Module has no attribute "command"; maybe "Command"?
error: Module has no attribute "option"; maybe "Option"?
error: Module has no attribute "IntRange"
error: Module has no attribute "Choice"
error: Name 'click.Context' is not defined
error: Module has no attribute "argument"; maybe "Argument"?
error: Module has no attribute "pass_context"
error: Module has no attribute "secho"; maybe "echo"?
error: Module has no attribute "echo"; maybe "secho"?

Anyone else seeing this or know what's up?

[davidism]

Please provide a minimal reproducible example. It's not clear that this is an issue with Click vs MyPy vs typeshed.

[tucked]

I'll work on that...

As another datapoint, I've asked about this on the Mypy Gitter and got this response:

That __init__.py needs from .x import Y as Y for mypy to recognize the re-exports I think

[tucked]

# foo.py
import click

def foo(option: click.Option) -> None:
    pass

python3 -m venv venv
venv/bin/pip install --upgrade 'click>=8' mypy
venv/bin/mypy --strict foo.py

foo.py:3: error: Name 'click.Option' is not defined
Found 1 error in 1 file (checked 1 source file)

[tucked]

I've updated the title because that repro ☝️ doesn't seem to happen without --strict.

[davidism]

You'll probably want to report this to mypy, as I have absolutely no idea how to address it. Need some typing experts to look at it.

[JelleZijlstra]

This is about the --no-implicit-reexport flag: https://mypy.readthedocs.io/en/stable/command_line.html#cmdoption-mypy-no-implicit-reexport. Click's __init__.py has a bunch of lines like from .module import Name. With that flag on, mypy doesn't treat such names as being re-exported, and to make it accept the code you need to do from .module import Name as Name.

That said this seems a bit too strict in this case, so maybe mypy should change its behavior to be more permissive here.

[davidism]

Thanks @JelleZijlstra, I'll close this for now as it seems to be a project config issue, not an issue with our types.

[tucked]

Workaround is to pin click<8 so that mypy falls back to using typeshed.

[davidism]

This is a configuration you add to your own project, not something we will change.

[mypy-click]
no_implicit_reexport = False