[Bug]: lua_ls hangs on startup

[AlexChalk]

Neovim version

0.9.4

Language affected

Lua

Query

No response

Strategy

No response

Description

When I enable rainbow-delimiters, lua_ls stalls at 0%. This is true even if I set the policy to 'noop' or blocklist lua in the plugin settings:

lua_ls config:

lspconfig.lua_ls.setup({
  on_attach = on_attach,
  capabilities = capabilities,
  settings = {
    Lua = {
      runtime = {
        -- Tell the language server which version of Lua you're using (most likely LuaJIT in the case of Neovim)
        version = "LuaJIT",
        -- Setup your lua path
        path = runtime_path,
      },
      diagnostics = {
        -- Get the language server to recognize the `vim` global
        globals = { "vim" },
      },
      workspace = {
        -- Make the server aware of Neovim runtime files
        library = vim.api.nvim_get_runtime_file("", true),
        checkThirdParty = false,
      },
      -- Do not send telemetry data containing a randomized but unique identifier
      telemetry = {
        enable = false,
      },
    },
  },
})

[HiPhish]

I think I have an idea what is going on. The plugin contains a symlink to itself in test/xdg/local/share/nvim/site/pack/testing/start/rainbow-delimiters. This symlink is used in testing, but it looks like your language server searches all directories of the plugin, which includes test, and ends up running in circles.

You can blacklist this particular directory (test/xdg) in your language server settings (workspace.ignoreDir). I don't know if it is possible to blacklist this directory in the repo itself so people don't have to do it in their own settings. Here are my Neovim settings:

-- Directory prefix of all package directories
local package_prefix = vim.fn.expand(vim.fn.stdpath('data') .. '/site/')

---Predicate which is only true for paths that belong to a package and have Lua
---modules.
---
---@param path string
---@return boolean
local function is_package_path(path)
    if package_prefix ~= string.sub(path, 1, #package_prefix) then
        return false
    end
    return vim.fn.isdirectory(path .. '/lua') ~= 0
end

local M = {
    Lua = {
        runtime = {
            -- When using `require`, how to find the file based on the input
            -- name.Setting this config to `?/init.lua` means that when you enter
            -- `require 'myfile'`, `${workspace}/myfile/init.lua` will be searched from
            -- the loaded files. if `runtime.pathStrict` is `false`,
            -- `${workspace}/**/myfile/init.lua` will also be searched. If you want to
            -- load files outside the workspace, you need to set `Lua.workspace.library`
            -- first.
            path = {
                'lua/?.lua',
                'lua/?/init.lua',
            },
            -- When enabled, `runtime.path` will only search the first level of
            -- directories, see the description of `runtime.path`.
            pathStrict = true,
        },
        workspace = {
            -- In addition to the current workspace, which directories will
            -- load files from. The files in these directories will be treated
            -- as externally provided code libraries, and some features (such
            -- as renaming fields) will not modify these files.
            --
            -- Very important: do not include the '/lua' subdirectory in the
            -- above paths! The runtime.path entry takes care of that.
            library = vim.tbl_filter(is_package_path, vim.api.nvim_get_runtime_file('', true)),
            -- Ignore the fake user directory structure in plugins.  This
            -- should be part of the `.luarc.json` of the plugin, but for some
            -- reason that does not work, so I define it here instead.
            ignoreDir = {'test/xdg'},
        },
    }
}

[AlexChalk]

Thanks for this, adding ignoreDir = { "test" } works for me 🎊.

I think this behaviour will happen for anyone using the default settings for lua_ls at https://github.com/neovim/nvim-lspconfig, so I suggest adding this info to the README. FWIW, as a user I'm fine with being asked to blocklist "test" dirs in my lua_ls config 🙏.

[HiPhish]

I don't think that it's appropriate to tell users to adjust their LSP configuration for this plugin. This plugin has nothing to do with LSP, so why should I force a particular configuration onto users?

I have gone ahead and removed the symlink, it will now be created on the fly during a test session and removed again afterwards. Can you please remove the ignoreDir setting and test whether it still works for you?

[AlexChalk]

It still works, thank you 🙌.

[HiPhish]

Closing this as done.