Pre-commit hooks for Formatting

[kursatyurt]

Proposed Changes

Even though the website has a style guide and the repo has a .clang-format file it has not strictly applied to pull requests. There is no style-checking workflow. As different users use different environment sometimes pull request contains unrelated style changes which makes the PR unreadable. This PR proposes to use pre-commit-hooks which are easy to use and enforce the style and adds a workflow check for formatting.

There is no formatted/style proposed for python files. This PR additionally proposes a black based python formatting that ensures the python files are consistent maximum line length is set to 120 to increase readability.

Moreover, pre-commit has additional hooks for the style of files.
The following ones are proposed:
trailing-whitespace - trims trailing whitespace. -> Especially useful for config files.
mixed-line-ending - replaces or checks mixed line ending.
end-of-file-fixer - ensures that a file is either empty or ends with one newline.

the pre-commit hooks can be easily installed via pip pip install pre-commit

PR Checklist

Put an X by all that apply. You can fill this out after submitting the PR. If you have any questions, don't hesitate to ask! We want to help. These are a guide for you to know what the reviewers will be looking for in your contribution.

• I am submitting my contribution to the develop branch.
• My contribution generates no new compiler warnings (try with --warnlevel=3 when using meson).
• My contribution is commented and consistent with SU2 style (https://su2code.github.io/docs_v7/Style-Guide/).
• I have added a test case that demonstrates my contribution, if necessary.
• I have updated appropriate documentation (Tutorials, Docs Page, config_template.cpp), if necessary.

[pcarruscag]

The order of includes may cause some issues

[kursatyurt]

The order of includes may cause some issues

Adding SortIncludes: Never solves this issue.

Now it works well on my PC, sorry I missed checking.

[pcarruscag]

Thanks. Is it possible to target only some paths for formatting? I'm concerned about making life too difficult for developers, and we cannot break lines in some files because we parse them to generate some python code.
Having only some paths we would then include more files over time until we cover everything.

[kursatyurt]

Thanks. Is it possible to target only some paths for formatting? I'm concerned about making life too difficult for developers, and we cannot break lines in some files because we parse them to generate some python code. Having only some paths we would then include more files over time until we cover everything.

@pcarruscag
The hook options of pre-commit hooks are here

As far as I understand yes it is possible with the files option (AFAIK it is a regex pattern) another option is excluding some directories now I only exclude the external directory.

I look at the regression test the values seem okay but the test fails is this due to wrappers? If you tell me which directories should be omitted, I would adjust it quickly. In general, we can also disable column limit/wrapping from clang-format but it is probably not the best option.

[pcarruscag]

Ill figure out the list of exclusions this weekend and let you know

[pcarruscag]

Alright, let's do the following, for now please exclude:
Common/include/CConfig.hpp
Common/include/option_structure.hpp
Common/src/CConfig.cpp
externals
legacy
SU2_CFD <- This one will cause conflicts for many branches so we should do it in steps
subprojects
TestCases (or if you can target only the .cfg in this directory it is also fine)

Please wait for #1903 and #1951 to be merged.
Add yourself to AUTHORS.md and thank you for automating the formatting.

[kursatyurt]

@pcarruscag , excellent, thank you.

[pcarruscag]

Alright, please go ahead when you can.

[pcarruscag]

Maybe start this fresh and force-push so that we don't get the history of the other formatting iterations.

[kursatyurt]

Ready to merge.

Please don't forget to add SU2_CFD probably in the v8 release :)

I will add the usage of pre-commit to the website soon.

[pcarruscag]

It seems you committed the old version of the submodules that were updated recently

[kursatyurt]

It seems you committed the old version of the submodules that were updated recently

Sorry for the mess, it is the first time for me with submodules. Cleaned.