TSUpdate does not install if up to date

doc/nvim-treesitter.txt

@@ -184,10 +184,15 @@ Supported options:
 COMMANDS                                            *nvim-treesitter-commands*
 
 								  *:TSInstall*
-:TSInstall| {language} ...~
+:TSInstall {language} ...~
 
 Install one or more treesitter parsers.
-You can use |:TSInstall| `all` to install all parsers.
+You can use |:TSInstall| `all` to install all parsers. Use |:TSInstall!| to
+force the reinstallation of already installed parsers.
+							      *:TSInstallSync*
+:TSInstallSync {language} ...~
+
+Perform the |:TSInstall| operation synchronously.
 
 							      *:TSInstallInfo*
 :TSInstallInfo~
@@ -195,10 +200,16 @@ You can use |:TSInstall| `all` to install all parsers.
 List informations about currently installed parsers
 
 								   *:TSUpdate*
-:TSUpdate {language}~
+:TSUpdate {language} ...~
 
-Update the installed parser of {language} or all installed parsers
+Update the installed parser for one more {language} or all installed parsers
-if {language} is omitted.
+if {language} is omitted. The specified parser is installed if it is not already
+installed.
+
+							       *:TSUpdateSync*
+:TSUpdateSync {language} ...~
+
+Perform the |:TSUpdate| operation synchronously.
 
 								*:TSUninstall*
 :TSUninstall {language}~

lua/nvim-treesitter/configs.lua

@@ -332,7 +332,7 @@ function M.setup(user_data)
 
   local ensure_installed = user_data.ensure_installed or {}
   if #ensure_installed > 0 then
-    require'nvim-treesitter.install'.ensure_installed(ensure_installed)
+    require'nvim-treesitter.install'.ensure_installed('',ensure_installed)
   end
 
   config.modules.ensure_installed = nil

lua/nvim-treesitter/install.lua

@@ -50,6 +50,10 @@ local function get_installed_revision(lang)
   end
 end
 
+local function is_installed(lang)
+  return #api.nvim_get_runtime_file('parser/'..lang..'.so', false) > 0
+end
+
 local function needs_update(lang)
   return not get_revision(lang) or get_revision(lang) ~= get_installed_revision(lang)
 end
@@ -280,9 +284,7 @@ local function run_install(cache_folder, install_folder, lang, repo, with_sync,
 end
 
 local function install_lang(bang, lang, cache_folder, install_folder, with_sync, generate_from_grammar)
-  if #api.nvim_get_runtime_file('parser/'..lang..'.so', false) > 0 then
+  if is_installed(lang) and bang ~= '!' then return 1 end
-      if bang ~= '!' then return 1 end
-  end
 
   local parser_config = parsers.get_parser_configs()[lang]
   if not parser_config then
@@ -305,7 +307,8 @@ local function install(options)
   local generate_from_grammar = options.generate_from_grammar
   local exclude_configured_parsers = options.exclude_configured_parsers
 
-  return function (bang, ...)
+  return function (bang)
+    return function (...)
       if fn.executable('git') == 0 then
         return api.nvim_err_writeln('Git is required on your system to run this command')
       end
@@ -341,13 +344,27 @@ local function install(options)
         print('Parsers already installed. Use :TSInstall! to force reinstallation.')
       end
     end
+  end
 end
 
-function M.update(bang, lang)
+function M.update(options)
+  options = options or {}
+  return function(bang)
+    return function (...)
       M.lockfile = {}
       reset_progress_counter()
-  if lang and lang ~= 'all' then
+      if ... and ... ~= 'all' then
-    install({})('!', lang)
+        local languages = vim.tbl_flatten({...})
+        local installed = 0
+        for _, lang in ipairs(languages) do
+            if (not is_installed(lang)) or (needs_update(lang)) then
+              installed = installed + 1
+              install({ with_sync = options.with_sync })('!')(lang)
+            end
+        end
+        if installed == 0 then
+          print('Parsers are up-to-date!')
+        end
       else
         local parsers_to_update = configs.get_update_strategy() == 'lockfile'
           and outdated_parsers()
@@ -357,13 +374,17 @@ function M.update(bang, lang)
         end
         for _, lang in pairs(parsers_to_update) do
           install({
-        exclude_configured_parsers = true
+            exclude_configured_parsers = true,
-      })('!', lang)
+            with_sync = options.with_sync
+          })('!')(lang)
+        end
+      end
     end
   end
 end
 
-function M.uninstall(bang,lang)
+function M.uninstall(bang)
+  return function (lang)
     local path_sep = '/'
     if fn.has('win32') == 1 then
       path_sep = '\\'
@@ -376,8 +397,8 @@ function M.uninstall(bang,lang)
         local maintained = parsers.maintained_parsers()
         installed = vim.tbl_filter(function(l) return vim.tbl_contains(maintained, l) end, installed)
       end
-    for _, lang in pairs(installed) do
+      for _, langitem in pairs(installed) do
-      M.uninstall(lang)
+        M.uninstall(langitem)
       end
     elseif lang then
       local install_dir, err = utils.get_parser_install_dir()
@@ -390,6 +411,7 @@ function M.uninstall(bang,lang)
       }
       M.iter_cmd(command_list, 1, lang, 'Treesitter parser for '..lang..' has been uninstalled')
     end
+  end
 end
 
 function M.write_lockfile(verbose, skip_langs)
@@ -453,10 +475,16 @@ M.commands = {
     },
   },
   TSUpdate = {
-    run = M.update,
+    run = M.update({}),
+    args = {
+      "-nargs=*",
+      "-complete=custom,nvim_treesitter#installed_parsers",
+    },
+  },
+  TSUpdateSync = {
+    run = M.update({ with_sync = true }),
     args = {
       "-nargs=*",
-      "-bang",
       "-complete=custom,nvim_treesitter#installed_parsers",
     },
   },
@@ -464,7 +492,6 @@ M.commands = {
     run = M.uninstall,
     args = {
       "-nargs=+",
-      "-bang",
       "-complete=custom,nvim_treesitter#installed_parsers",
     },
   },

lua/nvim-treesitter/utils.lua

@@ -6,7 +6,7 @@ local M = {}
 
 function M.setup_commands(mod, commands)
   for command_name, def in pairs(commands) do
-    local call_fn = string.format("lua require'nvim-treesitter.%s'.commands.%s.run('<bang>',<f-args>)", mod, command_name)
+    local call_fn = string.format("lua require'nvim-treesitter.%s'.commands.%s.run('<bang>')(<f-args>)", mod, command_name)
     local parts = vim.tbl_flatten({
       "command!",
       def.args,