Useful neovim commands to control native LSP (Neovim 0.12+) :LspInfo, :LspRestart, :LspStop

lsp_commands.lua

-- User commands to control native LSP (Neovim 0.12+)
-- Replace :LspInfo, :LspRestart, :LspStop, etc. that used to be provided by nvim-lspconfig
--
-- :LspList             → clients attached to the current buffer
-- :LspInfo             → :checkhealth vim.lsp (the official replacement for LspInfo)
-- :LspLog              → opens the LSP log in a new tab
-- :LspStop [name]      → stops clients (! to force)
-- :LspStart            → re-triggers autostart on the current buffer
-- :LspRestart [name]   → restarts clients and re-attaches the buffers
-- :LspCapabilities     → inspect the server's capabilities

-- ── Helpers ──────────────────────────────────────────────────────────

-- Target clients: by name(s) passed as args, or the ones from the current buffer
local function get_target_clients(fargs)
  if fargs and #fargs > 0 then
    local clients = {}
    for _, name in ipairs(fargs) do
      vim.list_extend(clients, vim.lsp.get_clients({ name = name }))
    end
    return clients
  end
  return vim.lsp.get_clients({ bufnr = 0 })
end

-- Autocomplete with names of active clients
local function complete_client_names(arglead)
  local seen, names = {}, {}
  for _, client in ipairs(vim.lsp.get_clients()) do
    if not seen[client.name] and vim.startswith(client.name, arglead) then
      seen[client.name] = true
      table.insert(names, client.name)
    end
  end
  return names
end

-- ── :LspList ─────────────────────────────────────────────────────────

vim.api.nvim_create_user_command("LspList", function()
  local clients = vim.lsp.get_clients({ bufnr = 0 })
  if vim.tbl_isempty(clients) then
    vim.notify("No LSP clients attached to this buffer", vim.log.levels.WARN)
    return
  end
  local lines = {}
  for _, c in ipairs(clients) do
    table.insert(lines, string.format("[%d] %s", c.id, c.name))
    table.insert(lines, string.format("    root: %s", c.root_dir or "(no root_dir)"))
    table.insert(lines, string.format("    cmd:  %s", type(c.config.cmd) == "table" and table.concat(c.config.cmd, " ") or "(function)"))
  end
  vim.notify(table.concat(lines, "\n"), vim.log.levels.INFO)
end, { desc = "List LSP clients attached to the current buffer" })

-- ── :LspInfo ─────────────────────────────────────────────────────────
-- In 0.12 the official replacement is :checkhealth vim.lsp

vim.api.nvim_create_user_command("LspInfo", function()
  vim.cmd("checkhealth vim.lsp")
end, { desc = "LSP info (checkhealth vim.lsp)" })

-- ── :LspLog ──────────────────────────────────────────────────────────

vim.api.nvim_create_user_command("LspLog", function()
  vim.cmd("tabnew " .. vim.fn.fnameescape(vim.lsp.get_log_path()))
end, { desc = "Open the LSP log" })

-- ── :LspStop ─────────────────────────────────────────────────────────
-- :LspStop            → stops the clients of the current buffer
-- :LspStop intelephense → stops a client by name
-- :LspStop!           → forces shutdown (SIGKILL)

vim.api.nvim_create_user_command("LspStop", function(opts)
  local clients = get_target_clients(opts.fargs)
  if vim.tbl_isempty(clients) then
    vim.notify("No clients found to stop", vim.log.levels.WARN)
    return
  end
  for _, client in ipairs(clients) do
    client:stop(opts.bang)
    vim.notify("Stopped: " .. client.name)
  end
end, {
  nargs = "*",
  bang = true,
  complete = complete_client_names,
  desc = "Stop LSP clients",
})

-- ── :LspStart ────────────────────────────────────────────────────────
-- Re-triggers the FileType event of the current buffer, which re-executes
-- autostart (works with both lspconfig and vim.lsp.enable)

vim.api.nvim_create_user_command("LspStart", function()
  vim.api.nvim_exec_autocmds("FileType", { buffer = 0 })
  vim.notify("LSP autostart re-triggered for this buffer")
end, { desc = "Start LSP on the current buffer" })

-- ── :LspRestart ──────────────────────────────────────────────────────
-- Saves config and buffers for each client, stops it, and after a delay
-- re-starts it re-attaching the same buffers.
-- Works regardless of how the client was started (lspconfig, vim.lsp.enable, etc.)

vim.api.nvim_create_user_command("LspRestart", function(opts)
  local clients = get_target_clients(opts.fargs)
  if vim.tbl_isempty(clients) then
    vim.notify("No clients found to restart", vim.log.levels.WARN)
    return
  end

  local saved = {}
  for _, client in ipairs(clients) do
    table.insert(saved, {
      name = client.name,
      config = client.config,
      bufs = vim.lsp.get_buffers_by_client_id(client.id),
    })
    client:stop(opts.bang)
  end

  vim.defer_fn(function()
    for _, item in ipairs(saved) do
      for _, buf in ipairs(item.bufs) do
        if vim.api.nvim_buf_is_valid(buf) and vim.api.nvim_buf_is_loaded(buf) then
          -- vim.lsp.start reuses the client if one already exists with the same config
          vim.lsp.start(item.config, { bufnr = buf })
        end
      end
      vim.notify("Restarted: " .. item.name)
    end
  end, 500)
end, {
  nargs = "*",
  bang = true,
  complete = complete_client_names,
  desc = "Restart LSP clients",
})

-- ── :LspCapabilities ─────────────────────────────────────────────────
-- Useful to know if the server supports formatting, inlayHints, etc.

vim.api.nvim_create_user_command("LspCapabilities", function(opts)
  local clients = get_target_clients(opts.fargs)
  if vim.tbl_isempty(clients) then
    vim.notify("No LSP clients in this buffer", vim.log.levels.WARN)
    return
  end
  for _, client in ipairs(clients) do
    -- Opens in a scratch buffer so you can search with /
    local buf = vim.api.nvim_create_buf(false, true)
    local lines = vim.split(vim.inspect(client.server_capabilities), "\n")
    vim.api.nvim_buf_set_lines(buf, 0, -1, false, lines)
    vim.api.nvim_buf_set_name(buf, "capabilities://" .. client.name)
    vim.bo[buf].filetype = "lua"
    vim.cmd.tabnew()
    vim.api.nvim_win_set_buf(0, buf)
  end
end, {
  nargs = "*",
  complete = complete_client_names,
  desc = "View LSP server capabilities",
})