Implement code style via pre-commit

[jorgepiloto]

Resolves #261.

[jorgepiloto]

The pylintrc file is not being used because pylint is not installed and neither executed in the CI. I think we can get rid of this file in favor of the other tools.

[dnwillia-work]

The pylintrc file is not being used because pylint is not installed and neither executed in the CI. I think we can get rid of this file in favor of the other tools.

Some of us were using it locally. I guess it means installing these other tools locally instead.

You will have to fix up the ci.yml pipeline as well, since it is depending on flake8 right, and run precommit now?

[jorgepiloto]

From private discussion with @seanpearsonuk, he pointed the usage of "pylint" locally, as @dnwillia-work explained in previous comment too.

Knowing this, my suggestion is to keep the usage of "pylint" and move its configuration from "pylintrc -> .pylintrc", see official pylint docs.

[jorgepiloto]

I will also modify the CI actions to work with pre-commit, @dnwillia-work.

[dnwillia-work]

Jorge, it looks ok though I wonder if it's worth reformatting all the generated code:

• everything in api.fluent.v0
• interface defined by fluent.core.meshing.tui.
• interface defined by fluent.core.solver.tui.
• interface defined by fluent.core.solver.settings

The first one is generated using grpcio tools, the latter three are generated using codegen/tuigen.py and codegen/settingsgen.py accordingly. The codegen tools should probably be updated to use correct formatting but if that's not easy then I guess we could rely on the code formatter to deal with it.... Maybe you can call the code formatter explicitly after the fact in the codegen modules?

[jorgepiloto]

Thanks for pointing this out, @dnwillia-work. I agree with excluding automated code from the formatting.

It is true that we could execute the formatting tools in the last step of the codegen/*gen.py files, but this would introduce another source of maintenance instead of having all format config under the pre-commit-config.yaml.

[jorgepiloto]

This issue psf/black#438 delayed me a bit when excluding files in .pre-commit-config.yaml. Same applies for flake8. I finally managed to solve it.

[jorgepiloto]

Already setup black, isort and flake8. Still working on the codespell and pydocstyle tools for excluding desired files... ⚙️

[jorgepiloto]

Only task left before labeling this as "Ready for review" is to manually apply code style for flake8, codespell and pydocstyle. This last is going to be most tedious one. I guess we could ignore some of the most common error codes.

[jorgepiloto]

Even though I setup [pydocstyle], I finally decided to disable it by commenting its lines in the pre-commit-config.yaml. The reason is due to the large amount of "errors" about required extra lines, missing docstrings... We can address this in a separate issue and merge this PR.

What do you think, @seanpearsonuk @dnwillia-work @mkundu1?