feat(server): provide cli invocation

[kanej]

Allow the server to be run at the cli with:

nomicfoundation-solidity-language-server --stdio

The readme has been updated to cover installation and running the language server through neovim's lsp.

Resolves #341.

Testing locally

Build the repo and link the language server:

yarn build
cd ./server
npm link
# check you can run the server
nomicfoundation-solidity-language-server --stdio

You need to setup neovim. I used the following as my init.lua:

local cmd = vim.cmd
local o = vim.o -- For the globals options
local wo = vim.wo -- For the window local options
local bo = vim.bo -- For the buffer local options

-- ---------------------------------
-- Setup Packer and plugins
-- ---------------------------------
local ensure_packer = function()
  local fn = vim.fn
  local install_path = fn.stdpath('data')..'/site/pack/packer/start/packer.nvim'
  if fn.empty(fn.glob(install_path)) > 0 then
    fn.system({'git', 'clone', '--depth', '1', 'https://github.com/wbthomason/packer.nvim', install_path})
    cmd [[packadd packer.nvim]]
    return true
  end
  return false
end

local packer_bootstrap = ensure_packer()

require('packer').startup(function(use)
  use 'wbthomason/packer.nvim'
  -- colorscheme
  use "EdenEast/nightfox.nvim"

  use 'nvim-treesitter/nvim-treesitter'

  use 'neovim/nvim-lspconfig'

  if packer_bootstrap then
    require('packer').sync()
  end
end)

-- ----------------------------------------
-- Setup treesitter for syntax highlighting
-- ----------------------------------------

require'nvim-treesitter.configs'.setup {
  -- A list of parser names, or "all"
  ensure_installed = { "c", "lua", "rust" },

  -- Install parsers synchronously (only applied to `ensure_installed`)
  sync_install = true,

  -- Automatically install missing parsers when entering buffer
  -- Recommendation: set to false if you don't have `tree-sitter` CLI installed locally
  auto_install = true,

  -- List of parsers to ignore installing (for "all")
  ignore_install = { "javascript" },

  ---- If you need to change the installation directory of the parsers (see -> Advanced Setup)
  -- parser_install_dir = "/some/path/to/store/parsers", -- Remember to run vim.opt.runtimepath:append("/some/path/to/store/parsers")!

  highlight = {
    -- `false` will disable the whole extension
    enable = true,

    -- NOTE: these are the names of the parsers and not the filetype. (for example if you want to
    -- disable highlighting for the `tex` filetype, you need to include `latex` in this list as this is
    -- the name of the parser)
    -- list of language that will be disabled
    disable = { "c", "rust" },
    -- Or use a function for more flexibility, e.g. to disable slow treesitter highlight for large files
    disable = function(lang, buf)
        local max_filesize = 100 * 1024 -- 100 KB
        local ok, stats = pcall(vim.loop.fs_stat, vim.api.nvim_buf_get_name(buf))
        if ok and stats and stats.size > max_filesize then
            return true
        end
    end,

    -- Setting this to true will run `:h syntax` and tree-sitter at the same time.
    -- Set this to `true` if you depend on 'syntax' being enabled (like for indentation).
    -- Using this option may slow down your editor, and you may see some duplicate highlights.
    -- Instead of true it can also be a list of languages
    additional_vim_regex_highlighting = false,
  },
}

-- ------------------------------------
-- Setup Language Servers via lspconfig
-- ------------------------------------

-- Mappings.
-- See `:help vim.diagnostic.*` for documentation on any of the below functions
local opts = { noremap=true, silent=true }
vim.keymap.set('n', '<space>e', vim.diagnostic.open_float, opts)
vim.keymap.set('n', '[d', vim.diagnostic.goto_prev, opts)
vim.keymap.set('n', ']d', vim.diagnostic.goto_next, opts)
vim.keymap.set('n', '<space>q', vim.diagnostic.setloclist, opts)

-- Use an on_attach function to only map the following keys
-- after the language server attaches to the current buffer
local on_attach = function(client, bufnr)
  -- Enable completion triggered by <c-x><c-o>
  vim.api.nvim_buf_set_option(bufnr, 'omnifunc', 'v:lua.vim.lsp.omnifunc')

  -- Mappings.
  -- See `:help vim.lsp.*` for documentation on any of the below functions
  local bufopts = { noremap=true, silent=true, buffer=bufnr }
  vim.keymap.set('n', 'gD', vim.lsp.buf.declaration, bufopts)
  vim.keymap.set('n', 'gd', vim.lsp.buf.definition, bufopts)
  vim.keymap.set('n', 'K', vim.lsp.buf.hover, bufopts)
  vim.keymap.set('n', 'gi', vim.lsp.buf.implementation, bufopts)
  vim.keymap.set('n', '<C-k>', vim.lsp.buf.signature_help, bufopts)
  vim.keymap.set('n', '<space>wa', vim.lsp.buf.add_workspace_folder, bufopts)
  vim.keymap.set('n', '<space>wr', vim.lsp.buf.remove_workspace_folder, bufopts)
  vim.keymap.set('n', '<space>wl', function()
    print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
  end, bufopts)
  vim.keymap.set('n', '<space>D', vim.lsp.buf.type_definition, bufopts)
  vim.keymap.set('n', '<space>rn', vim.lsp.buf.rename, bufopts)
  vim.keymap.set('n', '<space>ca', vim.lsp.buf.code_action, bufopts)
  vim.keymap.set('n', 'gr', vim.lsp.buf.references, bufopts)
  vim.keymap.set('n', '<space>f', function() vim.lsp.buf.format { async = true } end, bufopts)
end

local lsp_flags = {
  -- This is the default in Nvim 0.7+
  debounce_text_changes = 150,
}
require('lspconfig')['tsserver'].setup{
    on_attach = on_attach,
    flags = lsp_flags,
}

-- -----------------------------------------------
-- Setup Nomic Foundation Solidity Language Server
-- -----------------------------------------------

local lspconfig = require 'lspconfig'
local configs = require 'lspconfig.configs'

configs.solidity = {
  default_config = {
    cmd = {'nomicfoundation-solidity-language-server', '--stdio'},
    filetypes = { 'solidity' },
    root_dir = lspconfig.util.find_git_ancestor,
    single_file_support = true,
  },
}

lspconfig.solidity.setup {
    on_attach = on_attach,
    flags = lsp_flags,
}

-- --------------
-- General config
-- --------------

vim.g.mapleader = ';'

o.termguicolors = true
o.syntax = 'on'
o.errorbells = false
o.smartcase = true
o.showmode = false
bo.swapfile = false
o.backup = false
o.undodir = vim.fn.stdpath('config') .. '/undodir'
o.undofile = true
o.incsearch = true
o.hidden = true
o.clipboard = "unnamedplus"
o.completeopt='menuone,noinsert,noselect'
bo.autoindent = true
bo.smartindent = true

o.tabstop = 2
o.softtabstop = 2
o.shiftwidth = 2
o.expandtab = true
wo.number = true
wo.relativenumber = false
wo.signcolumn = 'yes'
wo.wrap = false

cmd[[colorscheme nightfox]]

My grasp of neovim is limited, but the intent is to install packer, then through that tree-sitter and lspconfigs. Set both of those up and override the solidity settings.