black_to_ruff: automated migration of black configuration settings

[konstin]

Once the configuration for the formatter is implemented, we should write a tool, let's call it black_to_ruff, that automatically migrates as much of the black configuration to ruff configuration as possible. This should be based on or extend flake8_to_ruff which already reads some basic black config.

• Read the black configuration: line-length, target-version, skip-magic-trailing-comma, preview, include, exclude
• Find the relevant ruff configuration, pyproject.toml or ruff.toml`
• Ignore redundant options, warn and ignore for conflicting options
• rewrite (toml_edit) the toml configuration file

[MichaReiser]

We may want to consider a ruff init or ruff migrate command that is part of ruff instead of falke8_to_ruff which is an independent binary

[charliermarsh]

I'm sort of medium on this, based on my experience with flake8-to-ruff. It's a nice idea in theory but ends up being a pain to translate from another tool's settings to our own (for example, how would we do includes and excludes, where Black uses a single regular expression?). And the payoff hasn't been great since it's a one-time tool. (Perhaps the discoverability is low given that it's a separate package and not a subcommand.) My hope is that our configuration is close enough to Black's that the migration should be trivial to do by-hand...

This isn't a hard no, but rather, I question whether it's a worthwhile investment (upfront and in ongoing maintenance) vs. other areas.

[charliermarsh]

I'm gonna close this as I'd prefer not to invest effort here. There are few enough configuration knobs that it's probably easy to just port the configuration than to download and figure out how to run a separate tool :)