Ruff does not respect configurations to exclude certain directories

[Jarmos-san]

So, our current project follows a directory structure like this:

.
├── backend/
│   ├── ...
│   ├── some-file.py
│   └── ...
├── frontend/
│   ├── ...
│   ├── some-file.tsx
│   └── ...
├── another-service/
│   ├── ...
│   ├── some-file.py
│   └── ...
└── migrations/
    ├── env.py
    ├── README
    ├── script.py.mako
    └── ...

We don't want ruff to lint/format the generated files under the migrations directory. So far we tried configuring the pyproject.toml with the following entries:

[tool.ruff]
extend-select = ["D", "I", "RUF"]
ignore = ["D211", "D212"]
extend-exclude = ["migrations"]

But ruff still performs linting for some of the Python files located under the migrations directory. What's going on over here? Are our configurations wrong or is there something else we're probably missing out on?

[dhruvmanila]

Hi, thanks for using Ruff and opening the discussion. Is the migrations directory right where the pyproject.toml config file is? Is the structure similar to the one mentioned below? Can you also tell us how and where are you running ruff from?

.
├── pyproject.toml
└── migrations/
    ├── env.py
    ├── README
    ├── script.py.mako
    └── ...

[Jarmos-san]

My bad, that was a typo on the code snippet and I've edited it to showcase the correct configuration I'm using currently. The exact configuration which is the prime suspect can be found here in my Null-ls configuration.

[dhruvmanila]

Hey, sorry for the late reply. I've quickly glanced at your config and I'm unable to reproduce it using a minimal init.lua config file. Can you try the following steps and check if it's working?

Minimal init.lua

local root = vim.fn.fnamemodify('./.repro', ':p')

for _, name in ipairs { 'config', 'data', 'state', 'cache' } do
  vim.env[('XDG_%s_HOME'):format(name:upper())] = root .. '/' .. name
end

-- bootstrap lazy
local lazypath = root .. '/plugins/lazy.nvim'
if not vim.loop.fs_stat(lazypath) then
  vim.fn.system {
    'git',
    'clone',
    '--filter=blob:none',
    'https://github.com/folke/lazy.nvim.git',
    lazypath,
  }
end
vim.opt.runtimepath:prepend(lazypath)

local function config()
  local null_ls = require 'null-ls'

  local diagnostics = null_ls.builtins.diagnostics

  local sources = {
    diagnostics.ruff.with {
      prefer_local = '.venv/bin',
    },
  }

  null_ls.setup {
    border = 'rounded',
    sources = sources,
  }

  vim.keymap.set('n', '<leader>l', function()
    vim.diagnostic.open_float { scope = 'line' }
  end, { desc = 'Show line diagnostics' })
end

-- install plugins
local plugins = {
  'folke/tokyonight.nvim',
  -- add any other plugins here
  {
    'jose-elias-alvarez/null-ls.nvim',
    event = 'BufRead',
    dependencies = {
      'nvim-lua/plenary.nvim',
    },
    config = config,
  },
}

require('lazy').setup(plugins, {
  root = root .. '/plugins',
  defaults = { lazy = true },
})

vim.cmd.colorscheme 'tokyonight'

vim.g.mapleader = ' '

-- Global diagnostic configuration.
vim.diagnostic.config {
  float = {
    source = 'always',
  },
}

Using a /tmp directory, create a virtual environment and install ruff in it. Open a Python file in Neovim being in /tmp directory using the following command, create a SyntaxError and check if it's being highlighted:

nvim -n -u /path/to/minimal.lua t.py

Can you also check if you've any plugin installed which automatically updates the root directory for the editor? I think you can verify if the root directory is different than the one in the shell using :pwd command.

[Jarmos-san]

Thanks for sharing a detailed example to reproduce the issue, it has been very helpful! That said, I used the minimal.lua configuration file for Neovim, installed ruff in the venv and used a /tmp directory for the reproduction as well. I'm attaching a screenshot for further reference of what you asked for;

[dhruvmanila]

Hey, thanks for being patience. I found the problem. The way null-ls invokes Ruff is through the stdin interface i.e., it passes the content via stdin and uses the buffer name in the --stdin-filename. So, null-ls is invoking Ruff using the command:

ruff check -n -e --stdin-filename /home/user/project/migrations/env.py -`

Here, Ruff won't respect the exclude (and extend-exclude) option when an explicit path is passed to it. This is intentional and matches the behavior of black.

The solution is to pass the --force-exclude flag to force Ruff to respect those options. This is not done by null-ls:

https://github.com/jose-elias-alvarez/null-ls.nvim/blob/db09b6c691def0038c456551e4e2772186449f35/lua/null-ls/builtins/diagnostics/ruff.lua#L57-L63

Now that null-ls is deprecated I would recommend you to switch to another plugin such as nvim-lint which will behave in the same way as it doesn't pass the --force-exclude flag either.

Might I suggest to use the ruff-lsp server? :)

[Jarmos-san]

It makes sense now! Thanks for sharing a detailed explanation of the issue I have been facing so far. And yeah, I've been using Null-ls for a long time now, so I'll have to gradually migrate my configurations to an alternative some time soon enough.

Thanks for the sharing the insights once again.