Is it possible to run mypy pre-commit without making it fail?

Question

I would like to add the following to pre-commit for a team:

-   repo: https://github.com/pre-commit/mirrors-mypy
    rev: 'v0.720'
    hooks:
    -   id: mypy
        args: [--ignore-missing-imports]

My team is worried that this might be too strict. To have a gradual introduction, I would like this hook not to make the commit fail, but only to show the issues. Is that possible?

Answer 1

you can, but I wouldn't suggest it -- warning noise is likely to have your whole team ignore the entire output and the entire tool

here's how you would do such a thing (note that it has reduced portability due to bash -- mostly because the framework intentionally does not suggest this)

-   repo: https://github.com/pre-commit/mirrors-mypy
    rev: v0.720
    hooks:
    -   id: mypy
        verbose: true
        entry: bash -c 'mypy "$@" || true' --

two pieces make this work:

1. verbose: true always produces the output -- this option is really only intended for debugging purposes, but you can turn it on always (it can be noisy / annoying though)
2. bash + || true -- ignore the exit code

disclaimer: I am the author of pre-commit