config: nvim: add LSP support together with mason package manager

config/nvim/lua/plugins.lua

@@ -43,6 +43,38 @@ return require('packer').startup({
 			config = function() require('colorizer').setup() end,
 		}
 
+		--------------------
+		-- Package Manager
+		--------------------
+		use { -- portable package manager
+			'williamboman/mason.nvim',
+			config = load_config('mason'),
+		}
+		use { -- update helper for mason
+			'WhoIsSethDaniel/mason-tool-installer.nvim',
+			after = { 'mason.nvim' },
+			config = function() require('mason-tool-installer').setup({}) end,
+		}
+
+		--------------------
+		-- LSP Setup
+		--------------------
+		use { -- compatibility layer between mason and lspconfig + autoinstaller
+			'williamboman/mason-lspconfig.nvim',
+			after = { 'mason.nvim' },
+			requires = {
+				'neovim/nvim-lspconfig',
+			},
+		}
+		use { -- configuration layer for neovim LSP client
+			'neovim/nvim-lspconfig',
+			after = {
+				'mason-lspconfig.nvim',
+				'cmp-nvim-lsp',
+			},
+			config = load_config('lspconfig'),
+		}
+
 		--------------------
 		-- Snippets
 		--------------------
@@ -62,6 +94,10 @@ return require('packer').startup({
 		--------------------
 		-- Completion
 		--------------------
+		use { -- nvim-cmp source for nvim-lsp
+			'hrsh7th/cmp-nvim-lsp',
+			requires = { 'hrsh7th/nvim-cmp' },
+		}
 		use { -- nvim-cmp source for LuaSnip
 			'saadparwaiz1/cmp_luasnip',
 			requires = { 'hrsh7th/nvim-cmp' },
@@ -82,6 +118,7 @@ return require('packer').startup({
 		use { -- completion engine
 			'hrsh7th/nvim-cmp',
 			after = {
+				'cmp-nvim-lsp',
 				'cmp-buffer',
 				'cmp-path',
 				'cmp-cmdline',

config/nvim/lua/plugins/lspconfig.lua

@@ -0,0 +1,24 @@
+local map = require('utils').map -- import map
+
+require('mason-lspconfig').setup()
+require('mason-lspconfig').setup_handlers({
+	function(server_name) -- default handler
+		-- prepare nvim-cmp source
+		local capabilities = require('cmp_nvim_lsp').default_capabilities()
+		require('lspconfig')[server_name].setup({
+			-- announce nvim-cmp-lsp capabilities to each lsp server
+			capabilities = capabilities
+		})
+	end
+})
+
+-- lsp keybindings
+map('n', 'gd', '<cmd>lua vim.lsp.buf.definition()<CR>')
+map('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<CR>')
+map('n', 'K', '<cmd>lua vim.lsp.buf.hover()<CR>')
+map('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<CR>')
+map('n', 'gr', '<cmd>lua vim.lsp.buf.references()<CR>')
+map('n', '<C-k>', '<cmd>lua vim.lsp.buf.signature_help()<CR>')
+map('n', '<leader>rn', '<cmd>lua vim.lsp.buf.rename()<CR>')
+map('n', '<leader>ca', '<cmd>lua vim.lsp.buf.code_action()<CR>')
+map('n', '<leader>f', '<cmd>lua vim.lsp.buf.type_definition({ async = true })<CR>')

config/nvim/lua/plugins/mason.lua

@@ -0,0 +1,9 @@
+require('mason').setup({
+	ui = {
+		icons = {
+			package_installed = '✓',
+			package_pending = '➜',
+			package_uninstalled = '✗',
+		},
+	},
+})

config/nvim/lua/plugins/nvim-cmp.lua

@@ -10,6 +10,7 @@ cmp.setup({
 	formatting = {
 		format = function(entry, vim_item)
 			vim_item.menu = ({
+				nvim_lsp = '[LSP]',
 				buffer = '[Buffer]',
 				luasnip = '[Snippet]',
 			})[entry.source.name]