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

example-ruff-formatting.ipynb

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