set up mypy hook for incremental adoption

[danieleades]

as per the comment here - python-poetry/poetry#4510

for some reason i had to use different config to successfully exclude the _vendor directory

[neersighted]

Same as on poetry -- lets add some comments and rebase to fix the merge conflicts.

[danieleades]

@neersighted this should be good to go. Not sure what's caused that python 3.10 workflow failure

[branchv]

The mypy error is an open issue (see python/mypy#1393) and only occurs on 3.10 since collections.Mapping was removed (8th bullet). We could either:

1. Ignore it with # type: ignore
2. Replace it with a non-guarded from collections.abc import Mapping, given it's unneeded compatibility for python 2

[neersighted]

Go ahead with collections.abc -- we're slowly trying to rip out Python 2 compatibility from poetry and poetry core -- there's no reason not to use the correct import path these days.

[danieleades]

@neersighted do you mind triggering the CI for me?

[branchv]

fwiw, this looks good to me

[neersighted]

Please note that when I say 'like in Poetry,' I really mean 'like in the linked PR' that I am working to get merged.

python-poetry/poetry#4750

[danieleades]

i've aligned the pre-commit config with the pyproject.toml file. my only concern is that the blanket allow_missing_imports flag might be slightly too unrestrictive/untargeted. Then again, it appears to be baked into the pre-commit hook.

[neersighted]

Looks like we get a failure on pypy, which is interesting. Is this rebased onto the latest master?

[danieleades]

Looks like we get a failure on pypy, which is interesting. Is this rebased onto the latest master?

it is now

[danieleades]

Looks like we get a failure on pypy, which is interesting. Is this rebased onto the latest master?

python/typed_ast#111

[danieleades]

rebased on master again. let's see if that helps

[neersighted]

Looks like we get a failure on pypy, which is interesting. Is this rebased onto the latest master?

python/typed_ast#111

I think the better thing to do here is to not depend on mypy in pyproject.toml at all -- we run it only under pre-commit anyway. If the user chooses to install mypy separately, that can be their (partially unsupported) business I think.

Alternatively, we could add a marker to only install on CPython (see the black dep above) -- but I'm thinking we should just remove the black and isort deps in the future and rely on pre-commit as the main poetry repo does.

[danieleades]

Looks like we get a failure on pypy, which is interesting. Is this rebased onto the latest master?

python/typed_ast#111

I think the better thing to do here is to not depend on mypy in pyproject.toml at all -- we run it only under pre-commit anyway. If the user chooses to install mypy separately, that can be their (partially unsupported) business I think.

Alternatively, we could add a market to only install on CPython (see the black dep above) -- but I'm thinking we should just remove the black and isort deps in the future and rely on pre-commit as the main poetry repo does.

i've removed the mypy dep for now.