fish-lsp

Introducing the fish-lsp, a Language Server Protocol (LSP) implementation for the fish shell language.

Quick Start

Please choose a method to install the language server and configure a client to use fish-lsp in your editor.

A detailed explanation of how a language server connection works is described in the how it works section.

Why? 🐟

🦈 Efficiency: enhances the shell scripting experience with an extensive suite of intelligent text-editing features
🐡 Flexibility: allows for a highly customizable configuration
🐚 Guidance: friendly hints and documentation to comfortably explore command line tooling
🐬 Community: improved by a vibrant user base, with supportive and insightful feedback
🐙 Compatibility: integrates with a wide variety of tooling and language clients
🌊 Reliability: produces an editor agnostic developer environment, ensuring all fish user's have access to a consistent set of features

Features

Feature	Description	Status
Completion	Provides completions for commands, variables, and functions	✅
Hover	Shows documentation for commands, variables, and functions. Has special handlers for `--flag`, `commands`, `functions`, `variables`	✅
Signature Help	Shows the signature of a command or function	✅
Goto Definition	Jumps to the definition of a command, variable, or function	✅
Find References	Shows all references to a command, variable, or function	✅
Rename	Rename within matching global && local scope	✅
Document Symbols	Shows all commands, variables, and functions in a document	✅
Workspace Symbols	Shows all commands, variables, and functions in a workspace	✅
Document Formatting	Formats a document, full & selection	✅
Document Highlight / Semantic Token	Highlights all references to a command, variable, or function.	✅
Command Execution	Executes a server command from the client	✅
Code Action	Shows all available code actions	✖
Code Lens	Shows all available code lenses	✖
Logger	Logs all server activity	✅
Diagnostic	Shows all diagnostics	✅
Folding Range	Toggle ranges to fold text	✅
Telescope Integration	Integrates with the telescope.nvim plugin	✅
CLI Interactivity	Provides a CLI for server interaction. Built by `fish-lsp complete <option>`	✅
Client Tree	Shows the defined scope as a Tree	✅
Indexing	Indexes all commands, variables, and functions	✅

Installation

Some language clients might support downloading the fish-lsp directly from within the client, but for the most part, you'll typically be required to install the language server manually.

Below are a few methods to install the language server, and how to verify that it's working.

Use a Package Manager

Stability across package managers can vary. Consider using another installation method if issues arise.

npm install -g fish-lsp

yarn global add fish-lsp

pnpm install -g fish-lsp

nix-shell -p fish-lsp

If you installed the language server using a node based package manager (i.e. npm/yarn/pnpm), you can install the completions by running the following command:

fish-lsp complete > ~/.config/fish/completions/fish-lsp.fish

Build from Source

Recommended Dependencies: yarn@1.22.22 node@22.12.0 fish@3.7.1

git clone https://github.com/ndonfris/fish-lsp && cd fish-lsp
yarn install 
yarn dev # to watch for changes use `yarn dev:watch`

Using the yarn dev:watch command will automatically rebuild the project when changes are detected. This allows easy testing of new features or bug fixes, if you're interested in contributing.

Building the project from source is the most portable method for installing the language server.

Verifying Installation

After installation, verify that fish-lsp is working correctly:

fish-lsp --help

Setup

To properly configure fish-lsp, you need to define a client configuration after installing the language server.

Configuring a client should be relatively straightforward. Typically, you're only required to translate the shell command fish-lsp start for fish files, in the client's configuration. However, further configuration can be specified as a server configuration.

Some clients may also allow specifying the server configuration directly in the client configuration.

Client Configuration (Required)

Theoretically, the language-server should generally be compatible with almost any text-editor or IDE you prefer using. Feel free to setup the project in any fish-lsp-client of your choice, or submit a PR for new configurations.

neovim (v0.8)

Full table of options available in the neovim documentation

vim.api.nvim_create_autocmd('FileType', {
  pattern = 'fish',
  callback = function()
    vim.lsp.start({
      name = 'fish-lsp',
      cmd = { 'fish-lsp', 'start' },
      cmd_env = { fish_lsp_show_client_popups = false },
    })
  end,
})

Alternatively, you can also see official documentation for nvim-lspconfig, or use your client of choice below.

coc.nvim

Neovim client using coc.nvim configuration, located inside coc-settings.json "languageserver" key

{
  "fish-lsp": {
    "command": "fish-lsp",
    "filetypes": ["fish"],
    "args": ["start"]
  }
}

YouCompleteMe

YouCompleteMe configuration for vim/neovim

let g:ycm_language_server =
          \ [
          \   {
          \       'name': 'fish',
          \       'cmdline': [ 'fish-lsp', 'start' ],
          \       'filetypes': [ 'fish' ],
          \   }
          \ ]

vim-lsp

Configuration of prabirshrestha/vim-lsp in your init.vim or init.lua file

if executable('fish-lsp')
  au User lsp_setup call lsp#register_server({
      \ 'name': 'fish-lsp',
      \ 'cmd': {server_info->['fish-lsp', 'start']},
      \ 'allowlist': ['fish'],
      \ })
endif

helix

In config file ~/.config/helix/languages.toml

[[language]]
name = "fish"
language-servers = [ "fish-lsp" ]

[language-server.fish-lsp]
command = "fish-lsp"
args= ["start"]

kakoune

Configuration for kakoune-lsp, located in ~/.config/kak-lsp/kak-lsp.toml

[language.fish]
filetypes = ["fish"]
command = "fish-lsp"
args = ["start"]

Or in your ~/.config/kak/lsp.kak file

hook -group lsp-filetype-fish global BufSetOption filetype=fish %{
    set-option buffer lsp_servers %{
        [fish-lsp]
        root_globs = [ "*.fish", "config.fish", ".git", ".hg" ]
        args = [ "start" ]
    }
}

emacs

Configuration using eglot (Built into Emacs 29+)

;; Add to your init.el or .emacs
(require 'eglot)

(add-to-list 'eglot-server-programs
  '(fish-mode . ("fish-lsp" "start")))

;; Optional: auto-start eglot for fish files
(add-hook 'fish-mode-hook 'eglot-ensure)

or place in your languages/fish.el file

(use-package fish-mode)

(with-eval-after-load 'eglot
  (add-to-list 'eglot-server-programs
               '(fish-mode . ("fish-lsp" "start"))))

Configuration using lsp-mode

;; Add to your init.el or .emacs
(require 'lsp-mode)

(lsp-register-client
 (make-lsp-client
  :new-connection (lsp-stdio-connection '("fish-lsp" "start"))
  :activation-fn (lsp-activate-on "fish")
  :server-id 'fish-lsp))

;; Optional: auto-start lsp for fish files
(add-hook 'fish-mode-hook #'lsp)

Full example configuration using doom-emacs can be found in the fish-lsp language clients repo.

Server Configuration (Optional)

Specific functionality for the server can be set independently from the client. The server allows for both environment variables and command flags to customize how specific server processes are started.

Environment variables

Generated by fish-lsp env --create

# fish_lsp_enabled_handlers <ARRAY>
# enables the fish-lsp handlers (options: 'formatting', 'complete', 'hover', 'rename', 'definition', 'references', 'diagnostics', 'signatureHelp', 'codeAction', 'index')
set -gx fish_lsp_enabled_handlers

# fish_lsp_disabled_handlers <ARRAY>
# disables the fish-lsp handlers (options: 'formatting', 'complete', 'hover', 'rename', 'definition', 'references', 'diagnostics', 'signatureHelp', 'codeAction', 'index')
set -gx fish_lsp_disabled_handlers

# fish_lsp_commit_characters <ARRAY>
# array of the completion expansion characters. Single letter values only.
# Commit characters are used to select completion items, as shortcuts. (default: [])
set -gx fish_lsp_commit_characters

# fish_lsp_logfile <STRING>
# path to the logs.txt file (default: '')
# example locations could be: '~/path/to/fish-lsp/logs.txt' or '/tmp/fish_lsp.logs'
set -gx fish_lsp_logfile

# fish_lsp_all_indexed_paths <ARRAY>
# fish file paths/workspaces to include as workspaces (default: ['/usr/share/fish', "$HOME/.config/fish"])
set -gx fish_lsp_all_indexed_paths

# fish_lsp_modifiable_paths <ARRAY>
# fish file paths/workspaces that can be renamed by the user. (default: ["$HOME/.config/fish"])
set -gx fish_lsp_modifiable_paths

# fish_lsp_diagnostic_disable_error_codes <ARRAY>
# disable diagnostics for matching error codes (default: [])
# (options: 1001, 1002, 1003, 1004, 2001, 2002, 2003, 3001, 3002, 3003)
set -gx fish_lsp_diagnostic_disable_error_codes

# fish_lsp_max_background_files <NUMBER>
# maximum number of background files to read into buffer on startup (default: 1000)
set -gx fish_lsp_max_background_files

# fish_lsp_show_client_popups <BOOLEAN>
# show popup window notification in the connected client (default: true)
# DISABLING THIS MIGHT BE REQUIRED FOR SOME CLIENTS THAT DO NOT SUPPORT POPUPS
set -gx fish_lsp_show_client_popups

If you're interested in disabling specific diagnostic messages, the wiki includes a table of error codes that should be helpful. Diagnostics are a newer feature so PRs are welcome to improve their support.

Command Flags

Both the flags --enable and --disable are provided on the fish-lsp start subcommand. By default, all handlers will be enabled.

# displays what handlers are enabled. Removing the dump flag will run the server.
fish-lsp start --disable complete signature --dump

Further Server Configuration

Any flags will overwrite their corresponding environment variables, if both are seen for the fish-lsp process. For this reason, it is encouraged to wrap any non-standard behavior of the fish-lsp in functions or aliases.

Example edit_command_buffer wrapper to conditionally disable specific fish-lsp features

function edit_command_buffer_wrapper --description 'edit command buffer with custom server configurations'
  # place any CUSTOM server configurations here
  set -lx fish_lsp_diagnostic_disable_error_codes 1001 1002 1003 1004 2001 2002 2003 3001 3002 3003 
  set -lx fish_lsp_show_client_popups false

  # open the command buffer with the custom server configuration, without
  # overwriting the default server settings
  edit_command_buffer
end
bind \ee edit_command_buffer_wrapper
# now pressing alt+e in an interactive command prompt will open fish-lsp with the
# options set above, but opening the `$EDITOR` normally will still behave as expected

This allows normal editing of fish files to keep their default behaviour, while disabling unwanted server features for "interactive" buffers.

Due to the vast possibilities this project aims to support in the fish shell, sharing useful configurations is highly encouraged.

How does it work?

If you're new to the concept of the Language Server Protocol (LSP), this section should be useful to help you grasp its core purpose and benefits.

📸 Check out this insightful video by TJ DeVries for an introduction to the subject.

The LSP is designed to create a uniform approach for supporting a programming language across various development tools, moving beyond the confines of specific Text-Editor/IDE ecosystems. This standardization enhances a language's appeal by allowing developers to maintain consistent tooling support without needing to switch developer environments.

The core of this system is the interaction between a 'language server', which provides language services, and a 'language client', which consumes these services. The protocol facilitates this interaction, ensuring that any language client can leverage a well-defined set of features provided by the server.

Show a diagram to visualize a hypothetical fish-lsp process

Additional Resources

Contributing - documentation describing how to contribute to the fish-lsp project.
Roadmap - goals for future project releases.
Wiki - further documentation and knowledge relevant to the project
Discussions - interact with maintainers
Site - website homepage
Client Examples - testable language client configurations
Sources - major influences for the project

Contributors

Special thanks to anyone who contributed to the project! Contributions of any kind are welcome!

_nick 💻	_mimikun 💻	_{Jaakko Paju} 💻	_{Sean Perry} 💻	_{Fabio Coatti} 💻	_{Peter Cardenas} 💻	_{Peter Tri Ho} 💻
_bnwa 💻	_{Branch Vincent} 💻	_{Jaeseok Lee} 💻

This project follows the all-contributors specification.

License

MIT

fish-lsp

fish-lsp

Quick Start

Why? 🐟

Features

Installation

Use a Package Manager

Build from Source

Verifying Installation

Setup

Client Configuration (Required)

Server Configuration (Optional)

Environment variables

Command Flags

Further Server Configuration

How does it work?

Additional Resources

Contributors

License

Readme

Keywords

Package Sidebar

Install

Repository

Homepage

Weekly Downloads

Version

License

Unpacked Size

Total Files

Last publish

Collaborators

fish-lsp

fish-lsp

Quick Start

Why? 🐟

Features

Installation

Use a Package Manager

Build from Source

Verifying Installation

Setup

Client Configuration (Required)

Server Configuration (Optional)

Environment variables

Command Flags

Further Server Configuration

How does it work?

Additional Resources

Contributors

License

Readme

Keywords

Package Sidebar

Install

Repository

Homepage

DownloadsWeekly Downloads

Version

License

Unpacked Size

Total Files

Last publish

Collaborators

Weekly Downloads