feat(lspinfo): replace :LspInfo with :checkhealth #3339

Problem:
:LspInfo has its own "inner platlform" of highlights, mappings etc. And
it doesn't integrate with :checkhealth.

Solution:
- Move the lspinfo code to a healthcheck.
- LspInfo features such as highlights, "floating window" presentation,
  etc., should be added to :checkhealth in Nvim core, if they are really
  needed.
- Define a "q" mapping until Nvim stable has that in :checkhealth.

8 files changed, 94 insertions, 315 deletions

diff --git a/.editorconfig b/.editorconfig
index 26f3db25..edf2a6d8 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -1,7 +1,7 @@
 root = true
 
 [*]
-max_line_length = 100
+max_line_length = 120
 indent_style = space
 indent_size = 2
 tab_width = 8
diff --git a/.stylua.toml b/.stylua.toml
index 78c5507c..aaebb284 100644
--- a/.stylua.toml
+++ b/.stylua.toml
@@ -3,4 +3,4 @@ line_endings = "Unix"
 indent_type = "Spaces"
 indent_width = 2
 quote_style = "AutoPreferSingle"
-call_parentheses = "None"
+call_parentheses = "Input"
diff --git a/README.md b/README.md
index 29ba336b..29c68dcc 100644
--- a/README.md
+++ b/README.md
@@ -120,7 +120,7 @@ Most of the time, the reason for failure is present in the logs.
 
 ## Commands
 
-* `:LspInfo` shows the status of active and configured language servers.
+* `:LspInfo` (deprecated alias to `:che lspconfig`) shows the status of active and configured language servers.
 * `:LspStart <config_name>` Start the requested server name. Will only successfully start if the command detects a root directory matching the current config. Pass `autostart = false` to your `.setup{}` call for a language server if you would like to launch clients solely with this command. Defaults to all servers matching current buffer filetype.
 * `:LspStop <client_id>` Defaults to stopping all buffer clients.
 * `:LspRestart <client_id>` Defaults to restarting all buffer clients.
diff --git a/doc/lspconfig.txt b/doc/lspconfig.txt
index d5a44170..0ba19021 100644
--- a/doc/lspconfig.txt
+++ b/doc/lspconfig.txt
@@ -107,8 +107,7 @@ overrides to `setup{}` are:
   `pyright.disableOrganizeImports`: `boolean`
 
   Nested keys need to be translated into a nested table and passed to
-  the settings field in `setup{}` as follows:
->
+  the settings field in `setup{}` as follows: >lua
   require('lspconfig').pyright.setup{
     settings = {
       pyright = {
@@ -317,8 +316,8 @@ The `root_dir` key in `config` and `setup` can hold any function of the form
   returns nil | string
 >
 This allows for rich composition of root directory patterns which is necessary
-for some project structures. Example (for Kotlin):
->
+for some project structures. Example (for Kotlin): >lua
+
   local root_files = {
     'settings.gradle', -- Gradle (multi-project)
     'settings.gradle.kts', -- Gradle (multi-project)
@@ -369,6 +368,7 @@ standard for single-file mode, lspconfig will adopt that standard.
 COMMANDS                                                    *lspconfig-commands*
 
 :LspInfo                                                            *:LspInfo*
+Deprecated alias to `:check lspconfig`.
 Shows the status of all configured language servers. Note that client id
 refers to the Nvim RPC channel connected to a given language server. Also
 lists deprecated servers.
@@ -459,8 +459,8 @@ Note that it will not report any configuration changes applied in
 LOGGING                                                      *lspconfig-logging*
 
 When debugging language servers, it is helpful to enable additional logging in
-the built-in client, specifically considering the RPC logs. Example:
->
+the built-in client, specifically considering the RPC logs. Example: >lua
+
   vim.lsp.set_log_level 'trace'
   if vim.fn.has 'nvim-0.5.1' == 1 then
     require('vim.lsp.log').set_format_func(vim.inspect)
@@ -486,14 +486,10 @@ from `lspconfig` in time.
 ==============================================================================
 Highlights                                                *lspconfig-highlight*
 
-LspInfoTitle        Client name
-LspInfoList         Server name list
-LspInfoFiletype     `filetypes` area
-LspInfoTip          Tip
-LspInfoBorder       Window border
-    To set the border use: >
-        require('lspconfig.ui.windows').default_options.border = 'single'
-<    Accepts the same values as the `border` option to |nvim_open_win()|
+WARNING: The `require('lspconfig.ui.windows')` API was removed.
+LspInfo is provided by a healthcheck instead: >
+    :checkhealth lspconfig
+<
 
 ==============================================================================
 
diff --git a/lua/lspconfig.lua b/lua/lspconfig.lua
index 9c1ef7e3..3382259f 100644
--- a/lua/lspconfig.lua
+++ b/lua/lspconfig.lua
@@ -9,7 +9,7 @@ local M = {
 ---@class Alias
 ---@field to string The new name of the server
 ---@field version string The version that the alias will be removed in
----@field inconfig? boolean need shown in lspinfo
+---@field inconfig? boolean should display in healthcheck (`:checkhealth lspconfig`)
 local aliases = {
   ['fennel-ls'] = {
     to = 'fennel_ls',
diff --git a/lua/lspconfig/ui/lspinfo.lua b/lua/lspconfig/health.lua
index ac8e6c2b..24d3444f 100644
--- a/lua/lspconfig/ui/lspinfo.lua
+++ b/lua/lspconfig/health.lua
@@ -1,12 +1,14 @@
+local M = {}
+local health = require('vim.health')
+
 local api, fn = vim.api, vim.fn
-local windows = require 'lspconfig.ui.windows'
 local util = require 'lspconfig.util'
 
 local error_messages = {
-  cmd_not_found = 'Unable to find executable. Please check your path and ensure the server is installed',
-  no_filetype_defined = 'No filetypes defined, Please define filetypes in setup()',
+  cmd_not_found = 'Unable to find executable. Check your $PATH and ensure the server is installed.',
+  no_filetype_defined = 'No filetypes defined. Define filetypes in setup().',
   root_dir_not_found = 'Not found.',
-  async_root_dir_function = 'Asynchronous root_dir functions are not supported in :LspInfo',
+  async_root_dir_function = 'Asynchronous root_dir functions are not supported by `:checkhealth lspconfig`',
 }
 
 local helptags = {
@@ -22,12 +24,6 @@ local function trim_blankspace(cmd)
   return trimmed_cmd
 end
 
-local function indent_lines(lines, offset)
-  return vim.tbl_map(function(val)
-    return offset .. val
-  end, lines)
-end
-
 local function remove_newlines(cmd)
   cmd = trim_blankspace(cmd)
   cmd = table.concat(cmd, ' ')
@@ -78,7 +74,7 @@ local function make_config_info(config, bufnr)
     end)
     coroutine.resume(co)
     if root_dir then
-      config_info.root_dir = root_dir
+      config_info.root_dir = vim.fn.fnamemodify(root_dir, ':~')
     elseif coroutine.status(co) == 'suspended' then
       config_info.root_dir = error_messages.async_root_dir_function
     else
@@ -115,9 +111,8 @@ local function make_config_info(config, bufnr)
     }, info_lines)
   end
 
-  vim.list_extend(lines, indent_lines(info_lines, '\t'))
-
-  return lines
+  vim.list_extend(lines, info_lines)
+  return table.concat(lines, '\n')
 end
 
 ---@param client vim.lsp.Client
@@ -128,16 +123,12 @@ local function make_client_info(client, fname)
   client_info.cmd = cmd_type[type(client.config.cmd)](client.config)
   local workspace_folders = fn.has 'nvim-0.9' == 1 and client.workspace_folders or client.workspaceFolders
   local uv = vim.uv
-  local is_windows = uv.os_uname().version:match 'Windows'
-  fname = uv.fs_realpath(fname) or fn.fnamemodify(fn.resolve(fname), ':p')
-  if is_windows then
-    fname:gsub('%/', '%\\')
-  end
+  fname = vim.fs.normalize(uv.fs_realpath(fname) or fn.fnamemodify(fn.resolve(fname), ':p'))
 
   if workspace_folders then
     for _, schema in ipairs(workspace_folders) do
       local matched = true
-      local root_dir = uv.fs_realpath(schema.name)
+      local root_dir = vim.fn.fnamemodify(uv.fs_realpath(schema.name), ':~')
       if root_dir == nil or fname:sub(1, root_dir:len()) ~= root_dir then
         matched = false
       end
@@ -157,7 +148,6 @@ local function make_client_info(client, fname)
   client_info.attached_buffers_list = table.concat(vim.lsp.get_buffers_by_client_id(client.id), ', ')
 
   local lines = {
-    '',
     'Client: '
       .. client.name
       .. ' (id: '
@@ -179,30 +169,30 @@ local function make_client_info(client, fname)
     info_lines = vim.list_extend(info_lines, server_specific_info)
   end
 
-  vim.list_extend(lines, indent_lines(info_lines, '\t'))
+  vim.list_extend(lines, info_lines)
 
-  return lines
+  return table.concat(lines, '\n')
 end
 
-return function()
-  -- These options need to be cached before switching to the floating
-  -- buffer.
-  local original_bufnr = api.nvim_get_current_buf()
-  local buf_clients = util.get_lsp_clients { bufnr = original_bufnr }
-  local clients = util.get_lsp_clients()
-  local buffer_filetype = vim.bo.filetype
-  local fname = api.nvim_buf_get_name(original_bufnr)
-
-  windows.default_options.wrap = true
-  windows.default_options.breakindent = true
-  windows.default_options.breakindentopt = 'shift:25'
-  windows.default_options.showbreak = 'NONE'
+local function check_lspconfig(bufnr)
+  bufnr = (bufnr and bufnr ~= -1) and bufnr or nil
 
-  local win_info = windows.percentage_range_window(0.8, 0.7)
-  local bufnr, win_id = win_info.bufnr, win_info.win_id
-  vim.bo.bufhidden = 'wipe'
+  health.start('LSP configs active in this session (globally)')
+  health.info('Configured servers: ' .. table.concat(util.available_servers(), ', '))
+  local deprecated_servers = {}
+  for server_name, deprecate in pairs(require('lspconfig').server_aliases()) do
+    table.insert(deprecated_servers, ('%s -> %s'):format(server_name, deprecate.to))
+  end
+  if #deprecated_servers == 0 then
+    health.ok('Deprecated servers: (none)')
+  else
+    health.warn('Deprecated servers: ' .. table.concat(deprecated_servers, ', '))
+  end
 
-  local buf_lines = {}
+  local buf_clients = not bufnr and {} or vim.lsp.get_clients { bufnr = bufnr }
+  local clients = vim.lsp.get_clients()
+  local buffer_filetype = bufnr and vim.fn.getbufvar(bufnr, '&filetype') or '(invalid buffer)'
+  local fname = bufnr and api.nvim_buf_get_name(bufnr) or '(invalid buffer)'
 
   local buf_client_ids = {}
   for _, client in ipairs(buf_clients) do
@@ -216,91 +206,29 @@ return function()
     end
   end
 
-  -- insert the tips at the top of window
-  buf_lines[#buf_lines + 1] = 'Press q or <Esc> to close this window. Press <Tab> to view server doc.'
-
-  local header = {
-    '',
-    'Language client log: ' .. (vim.lsp.get_log_path()),
-    'Detected filetype:   ' .. buffer_filetype,
-  }
-  vim.list_extend(buf_lines, header)
-
-  local buffer_clients_header = {
-    '',
-    tostring(#vim.tbl_keys(buf_clients)) .. ' client(s) attached to this buffer: ',
-  }
-
-  vim.list_extend(buf_lines, buffer_clients_header)
+  health.start(('LSP configs active in this buffer (id=%s)'):format(bufnr or '(invalid buffer)'))
+  health.info('Language client log: ' .. (vim.fn.fnamemodify(vim.lsp.get_log_path(), ':~')))
+  health.info(('Detected filetype: `%s`'):format(buffer_filetype))
+  health.info(('%d client(s) attached to this buffer'):format(#vim.tbl_keys(buf_clients)))
   for _, client in ipairs(buf_clients) do
-    local client_info = make_client_info(client, fname)
-    vim.list_extend(buf_lines, client_info)
+    health.info(make_client_info(client, fname))
   end
 
-  local other_active_section_header = {
-    '',
-    tostring(#other_active_clients) .. ' active client(s) not attached to this buffer: ',
-  }
   if not vim.tbl_isempty(other_active_clients) then
-    vim.list_extend(buf_lines, other_active_section_header)
-  end
-  for _, client in ipairs(other_active_clients) do
-    local client_info = make_client_info(client, fname)
-    vim.list_extend(buf_lines, client_info)
+    health.info(('%s active client(s) not attached to this buffer:'):format(#other_active_clients))
+    for _, client in ipairs(other_active_clients) do
+      health.info(make_client_info(client, fname))
+    end
   end
 
-  local other_matching_configs_header = {
-    '',
-    'Other clients that match the filetype: ' .. buffer_filetype,
-    '',
-  }
-
-  local other_matching_configs = util.get_other_matching_providers(buffer_filetype)
-
+  local other_matching_configs = not bufnr and {} or util.get_other_matching_providers(buffer_filetype)
   if not vim.tbl_isempty(other_matching_configs) then
-    vim.list_extend(buf_lines, other_matching_configs_header)
+    health.info(('Other clients that match the "%s" filetype: '):format(buffer_filetype))
     for _, config in ipairs(other_matching_configs) do
-      vim.list_extend(buf_lines, make_config_info(config, original_bufnr))
+      health.info(make_config_info(config, bufnr))
     end
   end
 
-  local matching_config_header = {
-    '',
-    'Configured servers list: ' .. table.concat(util.available_servers(), ', '),
-  }
-  local deprecated_servers = {}
-  vim.list_extend(buf_lines, matching_config_header)
-  for server_name, deprecate in pairs(require('lspconfig').server_aliases()) do
-    table.insert(deprecated_servers, ('%s -> %s'):format(server_name, deprecate.to))
-  end
-  if #deprecated_servers > 0 then
-    vim.list_extend(buf_lines, { '', 'Deprecated servers: ' .. table.concat(deprecated_servers, ' ') })
-  end
-
-  local fmt_buf_lines = indent_lines(buf_lines, ' ')
-
-  api.nvim_buf_set_lines(bufnr, 0, -1, true, fmt_buf_lines)
-  vim.bo.modifiable = false
-  vim.bo.filetype = 'lspinfo'
-
-  local augroup = api.nvim_create_augroup('lspinfo', { clear = false })
-
-  local function close()
-    api.nvim_clear_autocmds { group = augroup, buffer = bufnr }
-    if api.nvim_win_is_valid(win_id) then
-      api.nvim_win_close(win_id, true)
-    end
-  end
-
-  vim.keymap.set('n', '<ESC>', close, { buffer = bufnr, nowait = true })
-  vim.keymap.set('n', 'q', close, { buffer = bufnr, nowait = true })
-  api.nvim_create_autocmd({ 'BufDelete', 'BufHidden' }, {
-    once = true,
-    buffer = bufnr,
-    callback = close,
-    group = augroup,
-  })
-
   vim.fn.matchadd(
     'Error',
     error_messages.no_filetype_defined
@@ -311,65 +239,52 @@ return function()
       .. error_messages.root_dir_not_found
   )
 
+  -- TODO(justimk): enhance :checkhealth's highlighting instead of doing this only for lspconfig.
   vim.cmd [[
     syn keyword String true
     syn keyword Error false
-    syn match LspInfoFiletypeList /\<filetypes\?:\s*\zs.*\ze/ contains=LspInfoFiletype
-    syn match LspInfoFiletype /\k\+/ contained
-    syn match LspInfoTitle /^\s*\%(Client\|Config\):\s*\zs\S\+\ze/
-    syn match LspInfoListList /^\s*Configured servers list:\s*\zs.*\ze/ contains=LspInfoList
-    syn match LspInfoList /\S\+/ contained
   ]]
 
-  api.nvim_buf_add_highlight(bufnr, 0, 'LspInfoTip', 0, 0, -1)
-
-  local function show_doc()
-    local lines = {}
-    local function append_lines(config)
-      if not config then
-        return
-      end
-      local desc = vim.tbl_get(config, 'config_def', 'docs', 'description')
-      if desc then
-        lines[#lines + 1] = string.format('# %s', config.name)
-        lines[#lines + 1] = ''
-        vim.list_extend(lines, vim.split(desc, '\n'))
-        lines[#lines + 1] = ''
-      end
-    end
+  return buf_clients, other_matching_configs
+end
 
-    lines[#lines + 1] = 'Press <Tab> to close server info.'
-    lines[#lines + 1] = ''
+local function check_lspdocs(buf_clients, other_matching_configs)
+  health.start('Docs for active configs:')
 
-    for _, client in ipairs(buf_clients) do
-      local config = require('lspconfig.configs')[client.name]
-      append_lines(config)
+  local lines = {}
+  local function append_lines(config)
+    if not config then
+      return
     end
-
-    for _, config in ipairs(other_matching_configs) do
-      append_lines(config)
+    local desc = vim.tbl_get(config, 'config_def', 'docs', 'description')
+    if desc then
+      lines[#lines + 1] = string.format('%s docs: >markdown', config.name)
+      lines[#lines + 1] = ''
+      vim.list_extend(lines, vim.split(desc, '\n'))
+      lines[#lines + 1] = ''
     end
+  end
 
-    local info = windows.percentage_range_window(0.8, 0.7)
-    lines = indent_lines(lines, ' ')
-    api.nvim_buf_set_lines(info.bufnr, 0, -1, false, lines)
-    api.nvim_buf_add_highlight(info.bufnr, 0, 'LspInfoTip', 0, 0, -1)
+  for _, client in ipairs(buf_clients) do
+    local config = require('lspconfig.configs')[client.name]
+    append_lines(config)
+  end
 
-    vim.bo[info.bufnr].filetype = 'markdown'
-    vim.bo[info.bufnr].syntax = 'on'
-    vim.wo[info.win_id].concealcursor = 'niv'
-    vim.wo[info.win_id].conceallevel = 2
-    vim.wo[info.win_id].breakindent = false
-    vim.wo[info.win_id].breakindentopt = ''
+  for _, config in ipairs(other_matching_configs) do
+    append_lines(config)
+  end
 
-    local function close_doc_win()
-      if api.nvim_win_is_valid(info.win_id) then
-        api.nvim_win_close(info.win_id, true)
-      end
-    end
+  health.info(table.concat(lines, '\n'))
+end
 
-    vim.keymap.set('n', '<TAB>', close_doc_win, { buffer = info.bufnr })
-  end
+function M.check()
+  -- XXX: :checkhealth switches to its buffer before invoking the healthcheck(s).
+  local orig_bufnr = vim.fn.bufnr('#')
+  local buf_clients, other_matching_configs = check_lspconfig(orig_bufnr)
+  check_lspdocs(buf_clients, other_matching_configs)
 
-  vim.keymap.set('n', '<TAB>', show_doc, { buffer = true, nowait = true })
+  -- XXX: create "q" mapping until :checkhealth has this feature in Nvim stable.
+  vim.cmd [[nnoremap <buffer> q <c-w>q]]
 end
+
+return M
diff --git a/lua/lspconfig/ui/windows.lua b/lua/lspconfig/ui/windows.lua
index dc02c9ef..616d30cd 100644
--- a/lua/lspconfig/ui/windows.lua
+++ b/lua/lspconfig/ui/windows.lua
@@ -1,129 +1,11 @@
--- The following is extracted and modified from plenary.vnim by
--- TJ Devries. It is not a stable API, and is expected to change
---
-local api = vim.api
-
-local function apply_defaults(original, defaults)
-  if original == nil then
-    original = {}
-  end
-
-  original = vim.deepcopy(original)
-
-  for k, v in pairs(defaults) do
-    if original[k] == nil then
-      original[k] = v
-    end
-  end
-
-  return original
-end
-
 local win_float = {}
 
 win_float.default_options = {}
 
-function win_float.default_opts(options)
-  options = apply_defaults(options, { percentage = 0.9 })
-
-  local width = math.floor(vim.o.columns * options.percentage)
-  local height = math.floor(vim.o.lines * options.percentage)
-
-  local top = math.floor(((vim.o.lines - height) / 2))
-  local left = math.floor((vim.o.columns - width) / 2)
-
-  local opts = {
-    relative = 'editor',
-    row = top,
-    col = left,
-    width = width,
-    height = height,
-    style = 'minimal',
-    border = {
-      { ' ', 'NormalFloat' },
-      { ' ', 'NormalFloat' },
-      { ' ', 'NormalFloat' },
-      { ' ', 'NormalFloat' },
-      { ' ', 'NormalFloat' },
-      { ' ', 'NormalFloat' },
-      { ' ', 'NormalFloat' },
-      { ' ', 'NormalFloat' },
-    },
-  }
-
-  opts.border = options.border and options.border
-
-  return opts
+function win_float.default_opts()
+  return {}
 end
 
---- Create window that takes up certain percentags of the current screen.
----
---- Works regardless of current buffers, tabs, splits, etc.
---@param col_range number | Table:
---                  If number, then center the window taking up this percentage of the screen.
---                  If table, first index should be start, second_index should be end
---@param row_range number | Table:
---                  If number, then center the window taking up this percentage of the screen.
---                  If table, first index should be start, second_index should be end
-function win_float.percentage_range_window(col_range, row_range, options)
-  options = apply_defaults(options, win_float.default_options)
-
-  local win_opts = win_float.default_opts(options)
-  win_opts.relative = 'editor'
-
-  local height_percentage, row_start_percentage
-  if type(row_range) == 'number' then
-    assert(row_range <= 1)
-    assert(row_range > 0)
-    height_percentage = row_range
-    row_start_percentage = (1 - height_percentage) / 3
-  elseif type(row_range) == 'table' then
-    height_percentage = row_range[2] - row_range[1]
-    row_start_percentage = row_range[1]
-  else
-    error(string.format("Invalid type for 'row_range': %p", row_range))
-  end
-
-  win_opts.height = math.ceil(vim.o.lines * height_percentage)
-  win_opts.row = math.ceil(vim.o.lines * row_start_percentage)
-  win_opts.border = options.border or 'none'
-
-  local width_percentage, col_start_percentage
-  if type(col_range) == 'number' then
-    assert(col_range <= 1)
-    assert(col_range > 0)
-    width_percentage = col_range
-    col_start_percentage = (1 - width_percentage) / 2
-  elseif type(col_range) == 'table' then
-    width_percentage = col_range[2] - col_range[1]
-    col_start_percentage = col_range[1]
-  else
-    error(string.format("Invalid type for 'col_range': %p", col_range))
-  end
-
-  win_opts.col = math.floor(vim.o.columns * col_start_percentage)
-  win_opts.width = math.floor(vim.o.columns * width_percentage)
-
-  local bufnr = options.bufnr or api.nvim_create_buf(false, true)
-  local win_id = api.nvim_open_win(bufnr, true, win_opts)
-  api.nvim_win_set_option(win_id, 'winhl', 'FloatBorder:LspInfoBorder')
-
-  for k, v in pairs(win_float.default_options) do
-    if k ~= 'border' then
-      vim.opt_local[k] = v
-    end
-  end
-
-  api.nvim_win_set_buf(win_id, bufnr)
-
-  api.nvim_win_set_option(win_id, 'cursorcolumn', false)
-  api.nvim_buf_set_option(bufnr, 'tabstop', 2)
-  api.nvim_buf_set_option(bufnr, 'shiftwidth', 2)
-
-  return {
-    bufnr = bufnr,
-    win_id = win_id,
-  }
-end
+function win_float.percentage_range_window() end
 
 return win_float
diff --git a/plugin/lspconfig.lua b/plugin/lspconfig.lua
index e5d924cc..fd4631d1 100644
--- a/plugin/lspconfig.lua
+++ b/plugin/lspconfig.lua
@@ -48,23 +48,9 @@ local get_clients_from_cmd_args = function(arg)
   return result
 end
 
-for group, hi in pairs {
-  LspInfoBorder = { link = 'Label', default = true },
-  LspInfoList = { link = 'Function', default = true },
-  LspInfoTip = { link = 'Comment', default = true },
-  LspInfoTitle = { link = 'Title', default = true },
-  LspInfoFiletype = { link = 'Type', default = true },
-} do
-  api.nvim_set_hl(0, group, hi)
-end
-
 -- Called from plugin/lspconfig.vim because it requires knowing that the last
 -- script in scriptnames to be executed is lspconfig.
-api.nvim_create_user_command('LspInfo', function()
-  require 'lspconfig.ui.lspinfo'()
-end, {
-  desc = 'Displays attached, active, and configured language servers',
-})
+api.nvim_create_user_command('LspInfo', ':che lspconfig', { desc = 'Deprecated alias to `:che lspconfig`' })
 
 api.nvim_create_user_command('LspStart', function(info)
   local server_name = string.len(info.args) > 0 and info.args or nil