If you want to help with the development of subwinder then feel free to pick up on any of the issues listed. If you would like to contribute a new feature or modify existing behavior then please raise an issue first to discuss the changes.
This library uses both black, flake8, and isort to lint and format code and for this reason these are all listed under the tool.poetry.dev-dependencies in the pyproject.toml. Please ensure any code contributed follows both of these (there are some incompatible rules between them that are ignored in either the .flake8 file or under tool.black and tool.isor in the pyproject.toml).
After making changes running flake8 ., black ., and isort --atomic . in the root of the repo should be enough to automatically format and make changes or nag. Testing with pytest will also flag if any of these are not up to date, so running the test suite should be enough to notice any problems.
Unit testing is done with the help of pytest (also one of the dev-dependencies). Make sure any changes you contribute pass the test suite, or fix the issue if the test suite is inaccurate. Preferably any new features should include tests to ensure the behavior is correct.
If you run into wanting to generate fake files to use with Media then you can look under the dev directory where fake_media.py can help you.