- Lint task requires [luacheck](https://github.com/luarocks/luacheck#installation) and [stylua](https://github.com/JohnnyMorganz/StyLua). If using nix, you can use `nix develop` to install these to a local nix shell.
The point of lspconfig is to provide the minimal configuration necessary for a server to act in compliance with the language server protocol. In general, if a server requires custom client-side commands or off-spec handlers, then the server configuration should be added *without* those in lspconfig and receive a dedicated plugin such as nvim-jdtls, nvim-metals, etc.
## Pull requests (PRs)
- To avoid duplicate work, create a draft pull request.
- Avoid cosmetic changes to unrelated files in the same commit.
- Use a [feature branch](https://www.atlassian.com/git/tutorials/comparing-workflows) instead of the master branch.
- Use a **rebase workflow** for small PRs.
- After addressing review comments, it's fine to rebase and force-push.
## Adding a server to lspconfig
The general form of adding a new language server is to start with a minimal skeleton. This includes populated the `config` table with a `default_config` and `docs` table.
When choosing a server name, convert all dashes (`-`) to underscores (`_`) If the name of the server is a unique name (`pyright`, `clangd`) or a commonly used abbreviation (`zls`), prefer this as the server name. If the server instead follows the pattern x-language-server, prefer the convention `x_ls` (`jsonnet_ls`).
`default_config` should include, at minimum the following:
*`cmd`: a list which includes the executable name as the first entry, with arguments constituting subsequent list elements (`--stdio` is common).
Note that Windows has a limitation when it comes to directly invoking a server that's installed by `npm` or `gem`, so it requires additional handling.
```lua
local bin_name = 'typescript-language-server'
local cmd = { bin_name, '--stdio' }
if vim.fn.has 'win32' == 1 then
cmd = { 'cmd.exe', '/C', bin_name, '--stdio' }
end
```
*`filetypes`: a list for filetypes a
*`root_dir`: a function (or function handle) which returns the root of the project used to determine if lspconfig should launch a new language server, or attach a previously launched server when you open a new buffer matching the filetype of the server. Note, lspconfig does not offer a dedicated single file mode (this is not codified in the spec). Do not add `vim.fn.cwd` or `util.path.dirname` in `root_dir`. A future version of lspconfig will provide emulation of a single file mode until this is formally codified in the specification. A good fallback is `util.find_git_ancestor`, see other configurations for examples.
Additionally, the following options are often added:
*`init_options`: a table sent during initialization, corresponding to initializationOptions sent in [initializeParams](https://microsoft.github.io/language-server-protocol/specifications/specification-3-17/#initializeParams) as part of the first request sent from client to server during startup.
*`settings`: a table sent during [`workspace/didChangeConfiguration`](https://microsoft.github.io/language-server-protocol/specifications/specification-3-17/#didChangeConfigurationParams) shortly after server initialization. This is an undocumented convention for most language servers. There is often some duplication with initOptions.
A minimal example for adding a new language server is shown below for `pyright`, a python language server included in lspconfig:
```lua
-- Only `configs` must be required, util is optional if you are using the root resolver functions, which is usually the case.
local configs = require 'lspconfig.configs'
local util = require 'lspconfig.util'
-- Having server name defined here is the convention, this is often times also the first entry in the `cmd` table.
local server_name = 'pyright'
configs[server_name] = {
default_config = {
-- This should be executable on the command line, arguments (such as `--stdio`) are additional entries in the list.
cmd = { 'pyright-langserver' },
-- These are the filetypes that the server will either attach or start in response to opening. The user must have a filetype plugin matching the filetype, either via the built-in runtime files or installed via plugin.
filetypes = { 'python' },
-- The root directory that lspconfig uses to determine if it should start a new language server, or attach the current buffer to a previously running language server.
root_dir = util.find_git_ancestor
end,
},
docs = {
-- The description should include at minimum the link to the github project, and ideally the steps to install the language server.
description = [[
https://github.com/microsoft/pyright
`pyright`, a static type checker and language server for python
`pyright` can be installed via `npm`
`npm install -g pyright`
]],
},
}
```
## Commit style
lspconfig, like neovim core, follows the [conventional commit style](https://www.conventionalcommits.org/en/v1.0.0-beta.2/) please submit your commits accordingly. Generally commits will be of the form:
PRs are checked with [luacheck](https://github.com/mpeterv/luacheck), [StyLua](https://github.com/JohnnyMorganz/StyLua) and [selene](https://github.com/Kampfkarren/selene). Please run the linter locally before submitting a PR:
Github Actions automatically generates `server_configurations.md`. Only modify `scripts/README_template.md` or the `docs` table in the server config (the lua file). Do not modify `server_configurations.md` directly.
