elixir-tools / docs / next-ls

Editors

Visual Studio Code

elixir-tools.vscode is a first party elixir-tools editor plugin and will install and manage Next LS for you.

Neovim

elixir-tools.nvim

elixir-tools.nvim is a first party elixir-tools editor plugin and will install and manage Next LS for you.

Note

If you are using a Neovim distribution like LunarVim, AstroVim, or NVChad, please make sure to disable any Elixir LSP support that comes out of the box, as it will interfere with elixir-tools.nvim.

nvim-lspconfig

Next LS support is built into nvim-lspconfig, you just need to install Next LS and set your cmd.

require("lspconfig")["nextls"].setup({
  cmd = {"nextls", "--stdio"},
  init_options = {
    extensions = {
      credo = { enable = true }
    },
    experimental = {
      completions = { enable = true }
    }
  }
})

Vim

Vim can be configured to run Next LS in conjunction with a few different Vim plugins.

prabirshrestha/vim-lsp

Install Next LS somewhere on your PATH, or instead use an absolute path to the Next LS executable.

if executable('nextls')
  au User lsp_setup call lsp#register_server({
      \ 'name': 'next_ls',
      \ 'cmd': ["nextls", "--stdio"],
      \ 'root_uri':{server_info->lsp#utils#path_to_uri(
      \	lsp#utils#find_nearest_parent_file_directory(
      \		lsp#utils#get_buffer_path(),
      \		['mix.exs']
      \	))},
      \ 'allowlist': ['elixir'],
      \ })
endif

yegappan/lsp - requires Vim 9

Install Next LS somewhere on your PATH, or instead use an absolute path to the Next LS executable.

let lspServers = [#{
\	  name: 'next_ls',
\	  filetype: ['elixir'],
\	  path: 'nextls',
\	  args: ['--stdio'],
\   rootSearchFiles: ['mix.exs']
\ }]
autocmd VimEnter * call LspAddServer(lspServers)

ALE

Valid once https://github.com/dense-analysis/ale/pull/4626 is merged.

Install Next LS somewhere on your PATH, or instead use an absolute path to the Next LS executable.

let g:ale_elixir_next_ls_executable = 'path/to/nextls' " optional, if you want to change the executable that is used
let g:ale_linters = {'elixir': ['next_ls']}

Emacs

Emacs can be configured to run Next LS in several flavors of Emacs.

Emacs with Eglot

eglot

(require 'eglot)

(add-to-list 'exec-path "path/to/next-ls/bin/")

(with-eval-after-load 'eglot
(add-to-list 'eglot-server-programs
   `((elixir-ts-mode heex-ts-mode elixir-mode) .
     ("nextls" "--stdio=true"))))

(add-hook 'elixir-mode-hook 'eglot-ensure)
(add-hook 'elixir-ts-mode-hook 'eglot-ensure)
(add-hook 'heex-ts-mode-hook 'eglot-ensure)

Initialization options can be configured:

(with-eval-after-load 'eglot
(add-to-list 'eglot-server-programs
   `((elixir-ts-mode heex-ts-mode elixir-mode) .
     ("nextls" "--stdio=true" :initializationOptions (:experimental (:completions (:enable t)))))))

Emacs with lsp-mode

lsp-mode

  1. Install nextls somewhere on your PATH
  2. Configure lsp-mode
(use-package lsp-mode
  :ensure t
  :hook (elixir-ts-mode . lsp)
  :commands lsp)
  1. Add nextls to the lsp-mode configuration
(with-eval-after-load 'lsp-mode
  (lsp-register-client
   (make-lsp-client :new-connection (lsp-stdio-connection '("nextls" "--stdio" ))
          :multi-root t
          ;; :initialization-options '(:experimental (:completions (:enable t))) ;; Enable the experimental completion mode
          :activation-fn (lsp-activate-on "elixir")
          :server-id 'next-ls)))

Doom Emacs with lsp-mode

Doom Emacs

lsp-mode is the default LSP client for Doom.

  1. Install nextls somewhere on your PATH
  2. Enable lsp with lsp-mode in $DOOMDIR/init.el
- ;; lsp
+ lsp
  1. Enable the Elixir layer with lsp in $DOOMDIR/init.el
- ;; elixir
+ (elixir +lsp)
  1. Configure the lsp-mode client in $DOOMDIR/config.el
(after! lsp-mode
  (lsp-register-client
   (make-lsp-client :new-connection (lsp-stdio-connection '("nextls" "--stdio"))
                    :multi-root t
                    :activation-fn (lsp-activate-on "elixir")
                    :server-id 'next-ls)))

Doom Emacs with Eglot

Doom Emacs

  1. Install nextls somewhere on your PATH
  2. Enable lsp with eglot in $DOOMDIR/init.el
- ;; lsp
+ (lsp +eglot)
  1. Enable the Elixir layer with lsp in $DOOMDIR/init.el
- ;; elixir
+ (elixir +lsp)
  1. Configure the eglot client in $DOOMDIR/config.el
(set-eglot-client! 'elixir-mode '("nextls" "--stdio"))

Helix

Add the following config to your ~/.config/helix/languages.toml.

[[language]]
name = "elixir"
scope = "source.elixir"
language-server = { command = "path/to/next-ls", args = ["--stdio=true"] }

If you are using the latest git version of helix use this:

[[language]]
name = "elixir"
scope = "source.elixir"
language-servers = ["nextls"]

[language-server.nextls]
command = "path/to/next-ls"
args = ["--stdio=true"]

TCP

Helix supports connecting via TCP using netcat. https://github.com/helix-editor/helix/wiki/How-to-install-the-default-language-servers

[[language]]
name = "elixir"
scope = "source.elixir"
language-server = { command = "nc", args = ["127.0.0.1", "9000"] }

If you are using the latest git version of helix use this:

[language-server.nextls]
command = "nc"
args = ["127.0.0.1", "9000"]

Initialization Options

Initialization options are configured with the config key.

[language-server.nextls]
command = "path/to/next-ls"
args = ["--stdio=true"]
config = { experimental = { completions = { enable = true } } }

Zed

Zed will install and manage Next LS for you. You can make next-ls the default with the following config:

{
  "languages": {
    "Elixir": {
      "language_servers": ["!lexical", "!elixir-ls", "next-ls"]
    },
    "HEEX": {
      "language_servers": ["!lexical", "!elixir-ls", "next-ls"]
    }
  }
}

Once it's on you can configure it by adding some options:

{
  "lsp": {
    // how you configure Next LS, notice the kebab casing
    "next-ls": {
      "initialization_options": {
        "extensions": {
          // example configuring the extensions
          "credo": { "enable": false }
        },
        "experimental": {
          // example configuring the experimental options
          "completions": { "enable": true }
        }
      }
    }
  }
}

And, if you want to run a local version of next-ls make sure your local build is in your path named nextls.

Sublime Text

Sublime Text support uses the LSP for Sublime Text package with the following configuration.

// Settings in here override those in "LSP/LSP.sublime-settings"
{
  "clients": {
    "elixir": {
      "command": ["nextls", "--stdio"],
      "selector": "source.elixir | source.ex | source.exs",
      "initializationOptions": {
        "extensions": {
          "credo": { "enable": true }
        },
        "experimental": {
          "completions": { "enable": true }
        }
      }
    }
  }
}