import on attach function from utils. export for reuseablility

init.lua

@@ -457,7 +457,7 @@ mason_lspconfig.setup_handlers {
   function(server_name)
     require('lspconfig')[server_name].setup {
       capabilities = capabilities,
-      on_attach = on_attach,
+      on_attach = require('custom.utils'),
       settings = servers[server_name],
     }
   end,

lua/custom/utils/init.lua

@@ -0,0 +1,47 @@
+local on_attach = function(_, 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.
+
+  print('RUNNING LSP ATTACHMENT')
+
+  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', vim.lsp.buf.definition, '[G]oto [D]efinition')
+  nmap('gr', require('telescope.builtin').lsp_references, '[G]oto [R]eferences')
+  nmap('gI', vim.lsp.buf.implementation, '[G]oto [I]mplementation')
+  nmap('<leader>D', vim.lsp.buf.type_definition, 'Type [D]efinition')
+  nmap('<leader>ds', require('telescope.builtin').lsp_document_symbols, '[D]ocument [S]ymbols')
+  nmap('<leader>ws', require('telescope.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' })
+end
+
+return on_attach