feat(workstation): set up LSP with nvim

4 files changed, 100 insertions, 0 deletions

diff --git a/nixos/profiles/workstation/dev.nix b/nixos/profiles/workstation/dev.nix
index 4c986a1..1b9100b 100644
--- a/nixos/profiles/workstation/dev.nix
+++ b/nixos/profiles/workstation/dev.nix
@@ -29,6 +29,7 @@
     # language servers
     nixd
     rust-analyzer
+    taplo
 
     # documentation
     man-pages # Linux development manual pages
diff --git a/nixos/profiles/workstation/graphical.nix b/nixos/profiles/workstation/graphical.nix
index 5c82d49..c633456 100644
--- a/nixos/profiles/workstation/graphical.nix
+++ b/nixos/profiles/workstation/graphical.nix
@@ -52,6 +52,10 @@
     [[ "$(tty)" == /dev/tty1 ]] && exec niri-session -l
   '';
 
+  fonts.packages = with pkgs; [
+    nerd-fonts.symbols-only
+  ];
+
   environment.systemPackages = with pkgs; [
     wmenu
     i3bar-river
diff --git a/nixos/profiles/workstation/pkgs/nvim.nix b/nixos/profiles/workstation/pkgs/nvim.nix
index 46a678c..aaedda6 100644
--- a/nixos/profiles/workstation/pkgs/nvim.nix
+++ b/nixos/profiles/workstation/pkgs/nvim.nix
@@ -19,5 +19,9 @@ pkgs.wrapNeovimUnstable pkgs.neovim-unwrapped {
       svelte
       typescript
     ]))
+
+    # For LSP. Language servers are installed in ../dev.nix.
+    nvim-lspconfig
+    blink-cmp
   ];
 }
diff --git a/user/nvim/init.lua b/user/nvim/init.lua
index 108f84a..c841a45 100644
--- a/user/nvim/init.lua
+++ b/user/nvim/init.lua
@@ -25,6 +25,90 @@ pick.setup({ source = { show = pick.default_show } })
 -- Reuse Neovim's popup-menu selection color for mini.pick's selected item.
 vim.api.nvim_set_hl(0, 'MiniPickMatchCurrent', { link = 'PmenuSel' })
 
+-- Show diagnostics inline at the end of the affected line.
+vim.diagnostic.config({ virtual_text = true })
+
+-- Enable language servers when they are available (for example, from a nix shell).
+local language_servers = {
+  {
+    name = 'gopls', cmd = { 'gopls' },
+    -- nvim-lspconfig's gopls root detection also invokes `go env`.
+    required_commands = { 'go' }
+  },
+  { name = 'lua_ls', cmd = { 'lua-language-server' } },
+  { name = 'nixd', cmd = { 'nixd' } },
+  { name = 'pyright', cmd = { 'pyright-langserver', '--stdio' } },
+  { name = 'rust_analyzer', cmd = { 'rust-analyzer' } },
+  { name = 'svelte', cmd = { 'svelteserver', '--stdio' } },
+  { name = 'taplo', cmd = { 'taplo', 'lsp', 'stdio' } },
+  { name = 'ts_ls', cmd = { 'typescript-language-server', '--stdio' } },
+}
+
+for _, server in ipairs(language_servers) do
+  local command = vim.fn.exepath(server.cmd[1])
+  local available = command ~= ''
+
+  for _, required_command in ipairs(server.required_commands or {}) do
+    if vim.fn.exepath(required_command) == '' then
+      available = false
+      break
+    end
+  end
+
+  if available then
+    server.cmd[1] = command
+    vim.lsp.config(server.name, { cmd = server.cmd })
+    vim.lsp.enable(server.name)
+  end
+end
+
+local function cursor_is_in_comment()
+  local row, col = unpack(vim.api.nvim_win_get_cursor(0))
+  local ok, captures = pcall(
+    vim.treesitter.get_captures_at_pos,
+    0,
+    row - 1,
+    math.max(col - 1, 0)
+  )
+
+  if not ok then
+    return false
+  end
+
+  return vim.iter(captures):any(function(capture)
+    return capture.capture == 'comment' or vim.startswith(capture.capture, 'comment.')
+  end)
+end
+
+require('blink.cmp').setup({
+  keymap = {
+    preset = 'default',
+    ['<CR>'] = {
+      'accept',
+      function()
+        if vim.fn.pumvisible() == 1 then
+          return vim.keycode('<C-y>')
+        end
+      end,
+      'fallback',
+    },
+  },
+  sources = {
+    -- Only show completion items provided by an attached LSP. This disables
+    -- blink.cmp's default buffer/path/snippet sources, which otherwise trigger
+    -- completions in plain text and Markdown files.
+    default = { 'lsp' },
+    transform_items = function(_, items)
+      -- Some LSPs do autocompletion in comments (e.g. nixd and lua_ls).
+      -- Ignore them in comments.
+      return cursor_is_in_comment() and {} or items
+    end,
+  },
+  completion = {
+    documentation = { auto_show = true },
+  },
+})
+
 -- Keyboard shortcuts
 
 -- Clear search highlighting with Escape.
@@ -35,6 +119,13 @@ vim.keymap.set('n', '<C-p>', function()
   pick.builtin.files({ tool = tool })
 end, { desc = 'Pick files' })
 
+vim.keymap.set('n', 'gd', vim.lsp.buf.definition, {
+  desc = 'LSP: Go to definition',
+})
+vim.keymap.set('n', 'gD', vim.lsp.buf.declaration, {
+  desc = 'LSP: Go to declaration',
+})
+
 -- Disable netrw's directory browser; directory buffers are handled below with MiniPick.
 vim.g.loaded_netrw = 1
 vim.g.loaded_netrwPlugin = 1