Steps to use `ruff` in JupyterLab with the `jupyterlab_code_formatter` plugin.

example-ruff-formatting.ipynb

Thank you very much for the great guide! A problem for me was that cells containing non-ascii unicode characters were not formatted. I could fix this by adding encoding="utf-8" in the subprocess.run() call.

Thank you for the comment! I'm thinking of revisiting this and seeing if I can make a PR to the extension itself. I'll add your change.

Hi!
Nice Guide!
in this Guide you just use the formater right?
Do you know how to get the ruff linter to work in jupyterlab?

I had to add the import "from typing import List" to the config file snippet. @jbwhit

Thanksk @nicornk -- I've added that to my snippet!

❤️

I am very happy with your config that can also reflect ruff configs written in pyproject.toml such as:

[tool.ruff.format]
quote-style = "single"

If you guys also want it to run check before format, then use this:

    @handle_line_ending_and_magic
    def format_code(
        self, code: str, notebook: bool, args: List[str] = [], **options
    ) -> str:
        # Lint
        linting = subprocess.run(
            [self.ruff_bin, "check", "--fix", "--exit-zero", "-"],
            input=code,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
            universal_newlines=True,
            encoding="utf-8",
        )
        
        # Format
        linted_code = linting.stdout
        process = subprocess.run(
            [self.ruff_bin, "format", "-"],
            input=linted_code,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
            universal_newlines=True,
            encoding="utf-8",
        )

        if process.stderr:
            logger.info(process.stderr)
            return code
        else:
            return process.stdout