Next LS

The language server for Elixir that just works. 😎

Still in heavy development, currently supporting the following features:

Compiler Diagnostics
Code Formatting
Workspace Symbols
Document Symbols
Go To Definition
Workspace Folders
Find References
Extensions
- Credo

Editor Support

Neovim: elixir-tools.nvim
VSCode: elixir-tools.vscode

Emacs

Using 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)

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"] }

Installation

The preferred way to use Next LS is through one of the supported editor extensions.

If you need to install Next LS on it's own, you can download the appropriate executable from our GitHub Releases.

These executables are created with Burrito and are completely standalone, except you'll still need Elixir and OTP installed in order for it to start a runtime for your application code.

Development

If you are making changes to Next LS and want to test them locally you can run bin/start --port 9000 to start the language server (port 9000 is just an example, you can use any port that you want as long as it is not being used already).

Then you can configure your editor to connect to Next LS using that port.

elixir-tools.nvim

{
  nextls = {enable = true, port = 9000}
}

Visual Studio Code

{
  "elixir-tools.nextls.adapter": "tcp",
  "elixir-tools.nextls.port": 9000
}

Note

Next LS creates an .elixir-tools hidden directory in your project, but it will be automatically ignored by git.

Troubleshooting

1. Is `epmd` running?

Linux/Mac:

pgrep -fl epmd

If epmd is not running, you might need to start it or ensure it starts automatically with your system. You can do this by running epmd -daemon.

2. Ensure `glibc` version is at least 2.34

Linux:

ldd --version

This will show the glibc version at the top. Ensure it's 2.34 or higher.

Mac:

macOS doesn't use glibc; it uses the Darwin C Library. Hence, this step is not applicable.

Windows:

Windows does not use glibc. If you're using a subsystem or tool that needs it, ensure it's updated.

3. Open Visual Studio Code from the terminal

To ensure that elixir is in your PATH, open Visual Studio Code from the terminal using the command-line tools.

4. Does it work in TCP mode?

All Platforms:

Start the language server in TCP mode and connect to it with your editor, as described above.

Both extensions install the Next LS executable to ~/.cache/elixir-tools/nextls/bin/nextls, so you can start the server with ~/.cache/elixir-tools/nextls/bin/nextls --port 9000.

5. Firewall Interference

Sometimes, the firewall can interfere with epmd and each Erlang node's ability to cluster. If you face connection issues, you might try turning off the firewall temporarily to see if it resolves the issue.

This is usually a problem on macOS, as you should see a popup asking if beam and epmd can accept incoming connections (which you should click "yes").

In future version, we plan to sign and notarize the darwin binaries, which should avoid this popups and make this a non-issue.

dvic/next-ls