lsp-lib

A library aimed at making the construction of language servers in Lua easier.

Note: This project is a work-in-progress. Expect features to change at any time!

Usage

lsp-lib is packaged as a module on LuaRocks, so it can be installed there as shown below.

$ luarocks --dev install lsp-lib

Lua Language Server definitions are included with the rock in lua_modules. The path is roughly outlined in the example below.

// in your .vscode/settings.json,
{
  "Lua.workspace.library": [
    // path to the CJSON addon, e.g. on Windows,
    "$USERPROFILE/AppData/Roaming/Code/User/globalStorage/sumneko.lua/addonManager/addons/lua-cjson/module/library",

    // this should point to this rock's types folder
    "lua_modules/lib/luarocks/rocks-5.X/lsp-lib/X.X.X/types"
  ]
}

These examples showcase some of the functions exposed by this library.

-- in Lua,
local null = require('cjson').null
local lsp = require('lsp-lib')

-- this allows adding fields to the type
---@class lsp*.Request
lsp.request = lsp.request

-- 'initialize' should auto-complete well enough under LuaLS
lsp.response['initialize'] = function(params)

  -- annotation is needed here due to a shortcoming of LuaLS
  ---@type lsp.Response.initialize.result
  return { capabilities = {} }
end

lsp.response['initialized'] = function()
  -- utility notify functions are provided
  lsp.notify.log.info(os.date())

  -- make a blocking LSP request
  lsp.config = assert(lsp.request.config())
end

lsp.response['shutdown'] = function()
  -- notify the client of something
  lsp.notify['$/cancelRequest'] { id = 0 }
  -- there is also a library function for this
  lsp.notify.cancel_request(0)

  return null
end

-- define your own request function
function lsp.request.custom_request(foo, bar)
  return lsp.request('$/customRequest', { foo = foo, bar = bar })
end

-- turn on debugging
-- currently logs anything received by or sent from this server
lsp.debug(true)

-- starts a loop that listens to stdio
lsp.listen()

-- in MoonScript,
import null from require 'cjson'

lsp = require 'lsp-lib'
import notify, request, listen from lsp

class Response extends lsp.response
  'initialize': (params) ->
    { capabilities: {} }

  'initialized': ->
    -- utility notify functions are provided
    notify.log.info os.date!

    -- make a blocking LSP request
    lsp.config = assert request.config!

  'shutdown': ->
    -- notify the client of something
    notify.cancel_request 0
    null

listen.routes = Response!

-- define your own request function
request.custom_request = (foo, bar) ->
  request '$/customRequest', { :foo, :bar }

-- turn on debugging
-- currently logs anything received by or sent from this server
lsp.debug true

-- starts a loop that listens to stdio
listen!

Documentation can be found here. (This is also not set up yet!)

Development Setup

$ git clone https://github.com/goldenstein64/lua-lsp-lib

# set up `.env` or `.envrc` with your environment manager
# For Windows, I recommend `PS-Dotenv`

$ luarocks build --deps-only --pin

The lsp-lib/ folder contains all the source code.

Testing

Tests are located in the spec/ folder. Busted and MoonScript are used to run them. They can be run using the following command.

$ luarocks test