darker VS deps

Thanks for your suggestions. I have gone through the GitHub issue that you have mentioned. From there I got to know about this plugin https://github.com/akaihola/darker

For Python, Darker does that by applying Black only to changed areas of the code. Maybe the same approach could be used for rustfmt by creating a separate tool?

Not an answer to your question but in the specific case of black you can instead use: https://github.com/akaihola/darker

For instance, we have a number of interesting features planned for the 1.5.0 release of Darker, a tool for running Black/isort/pylint/flake8 but limiting to only lines modified between two given Git commits.

I knew one library using "composite". - Darker: https://github.com/akaihola/darker/blob/master/action.yml - More details here: https://docs.github.com/en/actions/creating-actions/creating-a-composite-action

There's also Darker for only reformatting (using Black) the lines modified by commits.

Assuming the range you're interested in is a range with your changes, you should look at darker.

Yeah that's how we've used it. The results need manual checking, but together with darker https://github.com/akaihola/darker that's how we've been slowly ratcheting our Django monolith into a typed codebase.

No, as I understand it, Django project's stance on type hints is that they aren't going to be added any time soon, but they are willing to accept small PRs that are needed by external type-checkers on a case by case basis. Details here: https://github.com/django/deps/pull/65

yup, you can read about it here in the DEP (django equivalent of PEP): https://github.com/django/deps/blob/main/final/0201-simplified-routing-syntax.rst

As part of testing we also ran the indenter over Django's own source code with great results! What do you think, is it worth it to submit a Django Enhancement Proposal to properly indent all HTML files in the Django source code?