Not ignoring files even though it is excluded in Black config

[roniemartinez]

So here's a sample config for Black and setup.py is ignored by Black when you run it.

[tool.black]
extend-exclude = '''
# A regex preceded with ^/ will apply only to files and directories
# in the root of the project.
^/setup.py

However, darker is not respecting this configuration and still reformats setup.py

Additional detail: darker is set in Pycharm's File Watcher so it keeps reformatting excluded files.

[akaihola]

Hi @roniemartinez, thanks a lot for your report!

I'm wondering how Darker should behave if I'm using it to run e.g. Black, isort, Pylint and Mypy on my repository, and there's a Black exclude configured in [tool.black]. Should Darker still apply isort, Pylint and Mypy, and just skip Black reformatting for matching files?

[roniemartinez]

Hi @akaihola

Yes, it should still apply isort, Pylint and Mypy and skip Black. If Mypy has exclude, Darker should also consider it.

[akaihola]

That makes sense. On the technical side, these different tools are invoked differently by Darker, and in the case of Black, we bypass command line handling and file selection, and just submit the contents of the Python source code directly to black.format_str(). So we'll have to either figure out how to

• invoke Black's configuration parsing and file selection first, or
• reimplement enough of Black's configuration parsing in Darker, or
• invoke the Black main program with suitable arguments instead.

I don't now remember exactly why I ended up calling directly into Black internals, but there was a good reason at that time for sure. At least it doesn't harm performance since Python+Black don't need to be bootstrapped separately for each file.

[roniemartinez]

invoke Black's configuration parsing and file selection first

I guess the first option makes more sense because Darker is already reading Black's configuration in read_black_config() and the src path is also available.

darker/src/darker/black_diff.py

Line 79 in 694c06c

config = parse_pyproject_toml(value)

[akaihola]

Thanks @roniemartinez, I'll definitely look into this in the near future. Or feel free to contribute a patch as well!

[akaihola]

@roniemartinez would you like to review #171? Can I invite you as a collaborator on this project?

[roniemartinez]

@akaihola Thank you so much for the effort.