nvim-config/lua/lsp-setup.lua

-- [[ Configure LSP ]]
--  This function gets run when an LSP connects to a particular buffer.

-- See `:help telescope.builtin`
local builtin = require 'telescope.builtin'

local on_attach = function(client, bufnr)
  -- NOTE: Remember that lua is a real programming language, and as such it is possible
  -- to define small helper and utility functions so you don't have to repeat yourself
  -- many times.
  --
  -- In this case, we create a function that lets us more easily define mappings specific
  -- for LSP related items. It sets the mode, buffer and description for us each time.
  local nmap = function(keys, func, desc)
    if desc then
      desc = 'LSP: ' .. desc
    end

    vim.keymap.set('n', keys, func, { buffer = bufnr, desc = desc })
  end

  nmap('<leader>rn', vim.lsp.buf.rename, '[R]e[n]ame')
  nmap('<leader>ca', vim.lsp.buf.code_action, '[C]ode [A]ction')

  nmap('gd', builtin.lsp_definitions, '[G]oto [D]efinition')
  nmap('gr', builtin.lsp_references, '[G]oto [R]eferences')
  nmap('gI', builtin.lsp_implementations, '[G]oto [I]mplementation')
  nmap('<leader>D', builtin.lsp_type_definitions, 'Type [D]efinition')
  nmap('<leader>ds', builtin.lsp_document_symbols, '[D]ocument [S]ymbols')
  nmap('<leader>ws', builtin.lsp_dynamic_workspace_symbols, '[W]orkspace [S]ymbols')

  -- See `:help K` for why this keymap
  nmap('K', vim.lsp.buf.hover, 'Hover Documentation')
  nmap('<C-k>', vim.lsp.buf.signature_help, 'Signature Documentation')

  -- Lesser used LSP functionality
  nmap('gD', vim.lsp.buf.declaration, '[G]oto [D]eclaration')
  nmap('<leader>wa', vim.lsp.buf.add_workspace_folder, '[W]orkspace [A]dd Folder')
  nmap('<leader>wr', vim.lsp.buf.remove_workspace_folder, '[W]orkspace [R]emove Folder')
  nmap('<leader>wl', function()
    print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
  end, '[W]orkspace [L]ist Folders')

  -- Create a command `:Format` local to the LSP buffer
  vim.api.nvim_buf_create_user_command(bufnr, 'Format', function(_)
    vim.lsp.buf.format()
  end, { desc = 'Format current buffer with LSP' })

  -- The following two autocommands are used to highlight references of the
  -- word under your cursor when your cursor rests there for a little while.
  --    See `:help CursorHold` for information about when this is executed
  --
  -- When you move your cursor, the highlights will be cleared (the second autocommand).
  if client and client.server_capabilities.documentHighlightProvider then
    vim.api.nvim_create_autocmd({ 'CursorHold', 'CursorHoldI' }, {
      buffer = bufnr,
      callback = vim.lsp.buf.document_highlight,
    })

    vim.api.nvim_create_autocmd({ 'CursorMoved', 'CursorMovedI' }, {
      buffer = bufnr,
      callback = vim.lsp.buf.clear_references,
    })
  end
end

-- document existing key chains
require('which-key').register {
  ['<leader>c'] = { name = '[C]ode', _ = 'which_key_ignore' },
  ['<leader>d'] = { name = '[D]ocument', _ = 'which_key_ignore' },
  ['<leader>g'] = { name = '[G]it', _ = 'which_key_ignore' },
  ['<leader>h'] = { name = 'Git [H]unk', _ = 'which_key_ignore' },
  ['<leader>r'] = { name = '[R]ename', _ = 'which_key_ignore' },
  ['<leader>s'] = { name = '[S]earch', _ = 'which_key_ignore' },
  ['<leader>t'] = { name = '[T]oggle', _ = 'which_key_ignore' },
  ['<leader>w'] = { name = '[W]orkspace', _ = 'which_key_ignore' },
}
-- register which-key VISUAL mode
-- required for visual <leader>hs (hunk stage) to work
require('which-key').register({
  ['<leader>'] = { name = 'VISUAL <leader>' },
  ['<leader>h'] = { 'Git [H]unk' },
}, { mode = 'v' })

-- mason-lspconfig requires that these setup functions are called in this order
-- before setting up the servers.
require('mason').setup()
require('mason-lspconfig').setup()

-- Enable the following language servers
--  Feel free to add/remove any LSPs that you want here. They will automatically be installed.
--
--  Add any additional override configuration in the following tables. They will be passed to
--  the `settings` field of the server config. You must look up that documentation yourself.
--
--  If you want to override the default filetypes that your language server will attach to you can
--  define the property 'filetypes' to the map in question.
local servers = {
  rust_analyzer = {},
  omnisharp = {},
  tsserver = {},
  pyright = {},
  svelte = {},
  lua_ls = {
    Lua = {
      runtime = { version = 'LuaJIT' },
      workspace = {
        checkThirdParty = false,
        -- Tells lua_ls where to find all the Lua files that you have loaded
        -- for your neovim configuration.
        library = {
          '${3rd}/luv/library',
          unpack(vim.api.nvim_get_runtime_file('', true)),
        },
        -- If lua_ls is really slow on your computer, you can try this instead:
        -- library = { vim.env.VIMRUNTIME },
      },
      telemetry = { enable = false },
    },
  },
}

-- Setup neovim lua configuration
require('neodev').setup()

-- nvim-cmp supports additional completion capabilities, so broadcast that to servers
local capabilities = vim.lsp.protocol.make_client_capabilities()
capabilities = vim.tbl_deep_extend('force', capabilities, require('cmp_nvim_lsp').default_capabilities())

-- You can add other tools here that you want Mason to install
-- for you, so that they are available from within Neovim.
local ensure_installed = vim.tbl_keys(servers or {})
vim.list_extend(ensure_installed, {
  'stylua', -- Used to format lua code
})

require('mason-tool-installer').setup { ensure_installed = ensure_installed }

require('mason-lspconfig').setup {
  handlers = {
    function(server_name)
      local server = servers[server_name] or {}
      require('lspconfig')[server_name].setup {
        cmd = server.cmd,
        on_attach = on_attach,
        settings = server.settings,
        filetypes = server.filetypes,
        -- This handles overriding only values explicitly passed
        -- by the server configuration above. Useful when disabling
        -- certain features of an LSP (for example, turning off formatting for tsserver)
        capabilities = vim.tbl_deep_extend('force', {}, capabilities, server.capabilities or {}),
      }
    end,
  },
}

-- vim: ts=2 sts=2 sw=2 et