Lazy loading with lazy.nvim

Lots of you really like this lazy loading business. Let me show you how to defer everything using lazy.nvim.

Expand: manual setup of LSP servers

{
  -- Autocompletion
  {
    'hrsh7th/nvim-cmp',
    event = 'InsertEnter',
    config = function()
      local cmp = require('cmp')

      cmp.setup({
        sources = {
          {name = 'nvim_lsp'},
        },
        mapping = cmp.mapping.preset.insert({
          ['<C-Space>'] = cmp.mapping.complete(),
          ['<C-u>'] = cmp.mapping.scroll_docs(-4),
          ['<C-d>'] = cmp.mapping.scroll_docs(4),
        }),
        snippet = {
          expand = function(args)
            vim.snippet.expand(args.body)
          end,
        },
      })
    end
  },

  -- LSP
  {
    'neovim/nvim-lspconfig',
    cmd = 'LspInfo',
    event = {'BufReadPre', 'BufNewFile'},
    dependencies = {
      {'hrsh7th/cmp-nvim-lsp'},
    },
    init = function()
      -- Reserve a space in the gutter
      -- This will avoid an annoying layout shift in the screen
      vim.opt.signcolumn = 'yes'
    end,
    config = function()
      local lsp_defaults = require('lspconfig').util.default_config

      -- Add cmp_nvim_lsp capabilities settings to lspconfig
      -- This should be executed before you configure any language server
      lsp_defaults.capabilities = vim.tbl_deep_extend(
        'force',
        lsp_defaults.capabilities,
        require('cmp_nvim_lsp').default_capabilities()
      )

      -- LspAttach is where you enable features that only work
      -- if there is a language server active in the file
      vim.api.nvim_create_autocmd('LspAttach', {
        desc = 'LSP actions',
        callback = function(event)
          local opts = {buffer = event.buf}

          vim.keymap.set('n', 'K', '<cmd>lua vim.lsp.buf.hover()<cr>', opts)
          vim.keymap.set('n', 'gd', '<cmd>lua vim.lsp.buf.definition()<cr>', opts)
          vim.keymap.set('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<cr>', opts)
          vim.keymap.set('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<cr>', opts)
          vim.keymap.set('n', 'go', '<cmd>lua vim.lsp.buf.type_definition()<cr>', opts)
          vim.keymap.set('n', 'gr', '<cmd>lua vim.lsp.buf.references()<cr>', opts)
          vim.keymap.set('n', 'gs', '<cmd>lua vim.lsp.buf.signature_help()<cr>', opts)
          vim.keymap.set('n', '<F2>', '<cmd>lua vim.lsp.buf.rename()<cr>', opts)
          vim.keymap.set({'n', 'x'}, '<F3>', '<cmd>lua vim.lsp.buf.format({async = true})<cr>', opts)
          vim.keymap.set('n', '<F4>', '<cmd>lua vim.lsp.buf.code_action()<cr>', opts)
        end,
      })

      -- These are just examples. Replace them with the language
      -- servers you have installed in your system
      require('lspconfig').gleam.setup({})
      require('lspconfig').ocamllsp.setup({})
    end
  }
}

Expand: automatic setup of LSP servers

{
  {
    'williamboman/mason.nvim',
    lazy = false,
    opts = {},
  },

  -- Autocompletion
  {
    'hrsh7th/nvim-cmp',
    event = 'InsertEnter',
    config = function()
      local cmp = require('cmp')

      cmp.setup({
        sources = {
          {name = 'nvim_lsp'},
        },
        mapping = cmp.mapping.preset.insert({
          ['<C-Space>'] = cmp.mapping.complete(),
          ['<C-u>'] = cmp.mapping.scroll_docs(-4),
          ['<C-d>'] = cmp.mapping.scroll_docs(4),
        }),
        snippet = {
          expand = function(args)
            vim.snippet.expand(args.body)
          end,
        },
      })
    end
  },

  -- LSP
  {
    'neovim/nvim-lspconfig',
    cmd = {'LspInfo', 'LspInstall', 'LspStart'},
    event = {'BufReadPre', 'BufNewFile'},
    dependencies = {
      {'hrsh7th/cmp-nvim-lsp'},
      {'williamboman/mason.nvim'},
      {'williamboman/mason-lspconfig.nvim'},
    },
    init = function()
      -- Reserve a space in the gutter
      -- This will avoid an annoying layout shift in the screen
      vim.opt.signcolumn = 'yes'
    end,
    config = function()
      local lsp_defaults = require('lspconfig').util.default_config

      -- Add cmp_nvim_lsp capabilities settings to lspconfig
      -- This should be executed before you configure any language server
      lsp_defaults.capabilities = vim.tbl_deep_extend(
        'force',
        lsp_defaults.capabilities,
        require('cmp_nvim_lsp').default_capabilities()
      )

      -- LspAttach is where you enable features that only work
      -- if there is a language server active in the file
      vim.api.nvim_create_autocmd('LspAttach', {
        desc = 'LSP actions',
        callback = function(event)
          local opts = {buffer = event.buf}

          vim.keymap.set('n', 'K', '<cmd>lua vim.lsp.buf.hover()<cr>', opts)
          vim.keymap.set('n', 'gd', '<cmd>lua vim.lsp.buf.definition()<cr>', opts)
          vim.keymap.set('n', 'gD', '<cmd>lua vim.lsp.buf.declaration()<cr>', opts)
          vim.keymap.set('n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<cr>', opts)
          vim.keymap.set('n', 'go', '<cmd>lua vim.lsp.buf.type_definition()<cr>', opts)
          vim.keymap.set('n', 'gr', '<cmd>lua vim.lsp.buf.references()<cr>', opts)
          vim.keymap.set('n', 'gs', '<cmd>lua vim.lsp.buf.signature_help()<cr>', opts)
          vim.keymap.set('n', '<F2>', '<cmd>lua vim.lsp.buf.rename()<cr>', opts)
          vim.keymap.set({'n', 'x'}, '<F3>', '<cmd>lua vim.lsp.buf.format({async = true})<cr>', opts)
          vim.keymap.set('n', '<F4>', '<cmd>lua vim.lsp.buf.code_action()<cr>', opts)
        end,
      })

      require('mason-lspconfig').setup({
        ensure_installed = {},
        handlers = {
          -- this first function is the "default handler"
          -- it applies to every language server without a "custom handler"
          function(server_name)
            require('lspconfig')[server_name].setup({})
          end,
        }
      })
    end
  }
}