Add ruff linter plugin

[jhossbach]

WIP for the implementation of ruff linting for pylsp (see this discussion)
It passes the unit tests (as adapted from the flake8 unit tests).

I did come across one very peculiar error from ruff:

Error running ruff: error: Found argument '--line-length' which wasn't expected, or isn't valid in this context

  If you tried to supply '--line-length' as a value rather than a flag, use '-- --line-length'

Usage: ruff <FILES|--config <CONFIG>|--verbose|--quiet|--silent|--exit-zero|--watch|--fix|--no-cache|--select <SELECT>|--extend-select <EXTEND_SELECT>|--ignore <IGNORE>|--extend-ignore <EXTEND_IGNORE>|--exclude <EXCLUDE>|--extend-exclude <EXTEND_EXCLUDE>|--per-file-ignores <PER_FILE_IGNORES>|--format <FORMAT>|--show-files|--show-settings|--add-noqa|--dummy-variable-rgx <DUMMY_VARIABLE_RGX>|--target-version <TARGET_VERSION>|--autoformat|--stdin-filename <STDIN_FILENAME>> <--verbose|--quiet|--silent>

For more information try '--help'

Do you have any idea @charliermarsh? I have no MWE so far and could not reproduce this using the CLI (which should work exactly the same compared to subprocess.Popen). Maybe an old version?

I can upload the plugin to PyPi as soon as the PR is approved and merged.

[ccordoba12]

Thanks a lot @jhossbach for your work on this! I left some simple style suggestions to improve docstrings, otherwise looks good to me.

In case you haven't done it before, please check this guide to apply all my suggestions in a single commit by adding them to the batch.

[charliermarsh]

How do the LSP plugins find the Ruff executable? Do they expect it to be globally available? Or do users point the LSP to an interpreter?

[jhossbach]

How do the LSP plugins find the Ruff executable? Do they expect it to be globally available? Or do users point the LSP to an interpreter?

You can provide a path to your ruff executable through pylsp.plugins.ruff.executable, if nothing is provided the plugin will assume it to be available globally. We can change this by importing ruff directly as a python module once astral-sh/ruff#659 is implemented.
I'm open to suggestions on how to improve this if necessary :)

[charliermarsh]

@jhossbach - Who's responsible for publishing to PyPI? Let me know when it's live and I can give it a try in neovim!

[jhossbach]

@jhossbach - Who's responsible for publishing to PyPI? Let me know when it's live and I can give it a try in neovim!

On it 👍

[jhossbach]

@charliermarsh: The PyPi package is published: https://pypi.org/project/python-lsp-ruff/1.0.0/
Let me know if you have any troubles, thanks a lot for testing!

[charliermarsh]

@jhossbach - For some reason I'm getting this:

[ERROR][2022-12-10 15:00:59] .../vim/lsp/rpc.lua:733	"rpc"	"pylsp"	"stderr"	"2022-12-10 15:00:59,445 EST - ERROR - pylsp_ruff.ruff_lint - Error running ruff: error: Found argument '--isort' which wasn't expected, or isn't valid in this context\n\n  If you tried to supply '--isort' as a value rather than a flag, use '-- --isort'\n\nUsage: ruff <FILES|--config <CONFIG>|--verbose|--quiet|--silent|--exit-zero|--watch|--fix|--no-fix|--no-cache|--select <SELECT>|--extend-select <EXTEND_SELECT>|--ignore <IGNORE>|--extend-ignore <EXTEND_IGNORE>|--exclude <EXCLUDE>|--extend-exclude <EXTEND_EXCLUDE>|--fixable <FIXABLE>|--unfixable <UNFIXABLE>|--per-file-ignores <PER_FILE_IGNORES>|--format <FORMAT>|--show-source|--show-files|--show-settings|--add-noqa|--dummy-variable-rgx <DUMMY_VARIABLE_RGX>|--target-version <TARGET_VERSION>|--line-length <LINE_LENGTH>|--max-complexity <MAX_COMPLEXITY>|--autoformat|--stdin-filename <STDIN_FILENAME>|--explain <EXPLAIN>|--generate-shell-completion <SHELL>> <--verbose|--quiet|--silent>\n\nFor more information try '--help'\n\n"

...in the Neovim LSP logs. Any ideas?

[jhossbach]

Any ideas?

Hmm, can you try increasing the log level of pylsp when starting the lsp via nvim? If you use nvim-lspconfig you can specify the command with

require("lspconfig").pylsp.setup{ cmd={<path_to_pylsp>,  '-vvv', '--log-file', '/tmp/pylsp.log' } }

[charliermarsh]

Ahh, ok:

2022-12-10 15:17:56,629 EST - DEBUG - pylsp_ruff.ruff_lint - Got ruff settings: {'ignore': None, 'perFileIgnores': None, 'executable': 'ruff', 'lineLength': None, 'enabled': True, 'select': None, 'exclude': None, 'config': None}
2022-12-10 15:17:56,630 EST - DEBUG - pylsp_ruff.ruff_lint - Found pyproject file: /Users/crmarsh/workspace/ruff/./pyproject.toml
2022-12-10 15:17:56,633 EST - DEBUG - pylsp_ruff.ruff_lint - XXX
2022-12-10 15:17:56,633 EST - DEBUG - pylsp_ruff.ruff_lint - {'config': None, 'exclude': None, 'ignore': None, 'line-length': None, 'select': None, 'isort': {'force-wrap-aliases': True, 'combine-as-imports': True}}
2022-12-10 15:17:56,633 EST - DEBUG - pylsp_ruff.ruff_lint - ['--quiet', '--format=json', "--isort={'force-wrap-aliases': True, 'combine-as-imports': True}", '--', '-']
2022-12-10 15:17:56,633 EST - DEBUG - pylsp_ruff.ruff_lint - Calling ruff with args: ['--quiet', '--format=json', "--isort={'force-wrap-aliases': True, 'combine-as-imports': True}", '--', '-'] on '/Users/crmarsh/workspace/ruff/setup.py'
2022-12-10 15:17:56,908 EST - ERROR - pylsp_ruff.ruff_lint - Error running ruff: error: Found argument '--isort' which wasn't expected, or isn't valid in this context

  If you tried to supply '--isort' as a value rather than a flag, use '-- --isort'

Usage: ruff <FILES|--config <CONFIG>|--verbose|--quiet|--silent|--exit-zero|--watch|--fix|--no-fix|--no-cache|--select <SELECT>|--extend-select <EXTEND_SELECT>|--ignore <IGNORE>|--extend-ignore <EXTEND_IGNORE>|--exclude <EXCLUDE>|--extend-exclude <EXTEND_EXCLUDE>|--fixable <FIXABLE>|--unfixable <UNFIXABLE>|--per-file-ignores <PER_FILE_IGNORES>|--format <FORMAT>|--show-source|--show-files|--show-settings|--add-noqa|--dummy-variable-rgx <DUMMY_VARIABLE_RGX>|--target-version <TARGET_VERSION>|--line-length <LINE_LENGTH>|--max-complexity <MAX_COMPLEXITY>|--autoformat|--stdin-filename <STDIN_FILENAME>|--explain <EXPLAIN>|--generate-shell-completion <SHELL>> <--verbose|--quiet|--silent>

For more information try '--help'

[charliermarsh]

Most of the settings options in pyproject.toml aren't supported as command-line arguments (and in this case, it's not properly handling the nested options, like those under isort).

Instead of trying to pass in pyproject.toml options as command-line arguments like this:

# Load config from pyproject file if it exists
if pyproject_file:
  try:
      log.debug(f"Found pyproject file: {str(pyproject_file[0])}")

      with open(str(pyproject_file[0]), "rb") as pyproject_toml:
          toml_dict = tomllib.load(pyproject_toml)

      toml_config = toml_dict.get("tool", {}).get("ruff", {})

      # Update settings with local project settings
      for key, value in toml_config.items():
          settings[key] = value

  except (tomllib.TOMLDecodeError, OSError) as e:
      log.warning(f"Failed loading {str(pyproject_file)}: {e}")

...could we instead just pass --config=/path/to/pyproject.toml to Ruff, and let Ruff do the parsing of the pyproject.toml?

[charliermarsh]

(That may not even be necessary because Ruff will automatically find the nearest pyproject.toml in a parent directory? Unless Neovim intentionally has different behavior around workspaces and stuff.)

[jhossbach]

Good point, I also thought about letting ruff find the pyproject.toml file without the help of pylsp. I can't think of any reason why this would be necessary, but the same is done for python-lsp-black (which also finds the toml file as far as I know?)
Do you have any idea if/why pylsp needs to read the per-project config @ccordoba12?

[jhossbach]

@charliermarsh what's the order of configuration input for ruff? Is it project-config -> CLI arguments? Because in that case pylsp needs to at least be able to recognize that a [tools.ruff] table is present, otherwise it might overwrite it with the config that you pass when starting e.g. with neovim

[ccordoba12]

Do you have any idea if/why pylsp needs to read the per-project config @ccordoba12?

To load settings saved on it for other tools.

[charliermarsh]

Yeah, CLI arguments always have precedence over the pyproject.toml.

I think it should be fine to either: (1) let Ruff handle the pyproject.toml, and only pass CLI arguments that come directly from the LSP config (which could include config, allowing users to override); or (2) keep the current logic of letting the LSP find the pyproject.toml, pass it in as --config if the user hasn't provided a config override in the LSP settings.

[charliermarsh]

Created an issue to track at #2. Once resolved, we can probably go ahead and add a reference to this from the Ruff README too.