test/functional: clean up according to luacheck (part 2)

49 files changed, 121 insertions, 125 deletions

diff --git a/test/.luacheckrc b/test/.luacheckrc
index 4c8243ad7e..92e19d40e8 100644
--- a/test/.luacheckrc
+++ b/test/.luacheckrc
@@ -1,5 +1,13 @@
--- vim: ft=lua
+-- vim: ft=lua tw=80
 
+-- Don't report globals from luajit or busted (e.g. jit.os or describe).
 std = '+luajit +busted'
-cache = true
+
+-- One can't test these files properly; assume correctness.
 exclude_files = { '*/preload.lua' }
+
+-- Don't report unused self arguments of methods.
+self = false
+
+-- Rerun tests only if their modification time changed.
+cache = true
diff --git a/test/functional/api/menu_spec.lua b/test/functional/api/menu_spec.lua
index 34d23ca098..5b414fb559 100644
--- a/test/functional/api/menu_spec.lua
+++ b/test/functional/api/menu_spec.lua
@@ -19,7 +19,7 @@ describe("update_menu notification", function()
     screen:detach()
   end)
 
-  function expect_sent(expected)
+  local function expect_sent(expected)
     screen:wait(function()
       if screen.update_menu ~= expected then
         if expected then
diff --git a/test/functional/api/server_requests_spec.lua b/test/functional/api/server_requests_spec.lua
index 4c7122a549..a3ac864f79 100644
--- a/test/functional/api/server_requests_spec.lua
+++ b/test/functional/api/server_requests_spec.lua
@@ -95,13 +95,13 @@ describe('server -> client', function()
         eq('notified!', eval('rpcrequest('..cid..', "notify")'))
       end
 
-      local function on_request(method, args)
+      local function on_request(method)
         eq('notify', method)
         eq(1, eval('rpcnotify('..cid..', "notification")'))
         return 'notified!'
       end
 
-      local function on_notification(method, args)
+      local function on_notification(method)
         eq('notification', method)
         if notified == expected then
           stop()
diff --git a/test/functional/api/vim_spec.lua b/test/functional/api/vim_spec.lua
index eb4804f141..cba0b7533b 100644
--- a/test/functional/api/vim_spec.lua
+++ b/test/functional/api/vim_spec.lua
@@ -180,6 +180,8 @@ describe('vim_* functions', function()
   end)
 
   describe('err_write', function()
+    local screen
+
     before_each(function()
       clear()
       screen = Screen.new(40, 8)
diff --git a/test/functional/api/window_spec.lua b/test/functional/api/window_spec.lua
index 456252522d..17aacafe9b 100644
--- a/test/functional/api/window_spec.lua
+++ b/test/functional/api/window_spec.lua
@@ -1,9 +1,9 @@
 -- Sanity checks for window_* API calls via msgpack-rpc
 local helpers = require('test.functional.helpers')
-local clear, nvim, buffer, curbuf, curbuf_contents, window, curwin, eq, neq,
-  ok, feed, rawfeed, insert, eval = helpers.clear, helpers.nvim, helpers.buffer, helpers.curbuf,
+local clear, nvim, curbuf, curbuf_contents, window, curwin, eq, neq,
+  ok, feed, insert, eval = helpers.clear, helpers.nvim, helpers.curbuf,
   helpers.curbuf_contents, helpers.window, helpers.curwin, helpers.eq,
-  helpers.neq, helpers.ok, helpers.feed, helpers.rawfeed, helpers.insert, helpers.eval
+  helpers.neq, helpers.ok, helpers.feed, helpers.insert, helpers.eval
 local wait = helpers.wait
 
 -- check if str is visible at the beginning of some line
@@ -54,7 +54,7 @@ describe('window_* functions', function()
       insert("prologue")
       feed('100o<esc>')
       insert("epilogue")
-      win = curwin()
+      local win = curwin()
       feed('gg')
       wait() -- let nvim process the 'gg' command
 
diff --git a/test/functional/autocmd/tabclose_spec.lua b/test/functional/autocmd/tabclose_spec.lua
index 847362e3de..bf609d1846 100644
--- a/test/functional/autocmd/tabclose_spec.lua
+++ b/test/functional/autocmd/tabclose_spec.lua
@@ -1,7 +1,5 @@
 local helpers = require('test.functional.helpers')
-local clear, nvim, buffer, curbuf, curwin, eq, neq, ok =
-  helpers.clear, helpers.nvim, helpers.buffer, helpers.curbuf, helpers.curwin,
-  helpers.eq, helpers.neq, helpers.ok
+local clear, nvim, eq = helpers.clear, helpers.nvim, helpers.eq
 
 describe('TabClosed', function()
     describe('au TabClosed', function()
@@ -20,7 +18,6 @@ describe('TabClosed', function()
         end)
         describe('with NR as <afile>', function()
             it('matches when  closing a tab whose index is NR', function()
-                tmp_path = nvim('eval', 'tempname()')
                 nvim('command', 'au! TabClosed 2 echom "tabclosed:match"')
                 repeat 
                     nvim('command',  'tabnew')
diff --git a/test/functional/autocmd/tabnew_spec.lua b/test/functional/autocmd/tabnew_spec.lua
index d80644cd92..5ab504889b 100644
--- a/test/functional/autocmd/tabnew_spec.lua
+++ b/test/functional/autocmd/tabnew_spec.lua
@@ -1,7 +1,5 @@
 local helpers = require('test.functional.helpers')
-local clear, nvim, buffer, curbuf, curwin, eq, neq, ok =
-  helpers.clear, helpers.nvim, helpers.buffer, helpers.curbuf, helpers.curwin,
-  helpers.eq, helpers.neq, helpers.ok
+local clear, nvim, eq = helpers.clear, helpers.nvim, helpers.eq
 
 describe('TabNew', function()
     setup(clear)
@@ -15,7 +13,7 @@ describe('TabNew', function()
         end)
         describe('with FILE as <afile>', function()
             it('matches when opening a new tab for FILE', function()
-                tmp_path = nvim('eval', 'tempname()')
+                local tmp_path = nvim('eval', 'tempname()')
                 nvim('command', 'au! TabNew '..tmp_path..' echom "tabnew:match"')
                 eq("\ntabnew:4:3\ntabnew:match\n\""..tmp_path.."\" [New File]", nvim('command_output', 'tabnew '..tmp_path))
            end)
diff --git a/test/functional/autocmd/tabnewentered_spec.lua b/test/functional/autocmd/tabnewentered_spec.lua
index f220c15ef7..64b9a22f41 100644
--- a/test/functional/autocmd/tabnewentered_spec.lua
+++ b/test/functional/autocmd/tabnewentered_spec.lua
@@ -1,7 +1,5 @@
 local helpers = require('test.functional.helpers')
-local clear, nvim, buffer, curbuf, curwin, eq, neq, ok =
-  helpers.clear, helpers.nvim, helpers.buffer, helpers.curbuf, helpers.curwin,
-  helpers.eq, helpers.neq, helpers.ok
+local clear, nvim, eq = helpers.clear, helpers.nvim, helpers.eq
 
 describe('TabNewEntered', function()
     describe('au TabNewEntered', function()
@@ -15,7 +13,7 @@ describe('TabNewEntered', function()
         end)
         describe('with FILE as <afile>', function()
             it('matches when opening a new tab for FILE', function()
-                tmp_path = nvim('eval', 'tempname()')
+                local tmp_path = nvim('eval', 'tempname()')
                 nvim('command', 'au! TabNewEntered '..tmp_path..' echom "tabnewentered:match"')
                 eq("\n\""..tmp_path.."\" [New File]\ntabnewentered:4:4\ntabnewentered:match", nvim('command_output', 'tabnew '..tmp_path))
            end)
diff --git a/test/functional/autocmd/termclose_spec.lua b/test/functional/autocmd/termclose_spec.lua
index 265d857a42..0961340e61 100644
--- a/test/functional/autocmd/termclose_spec.lua
+++ b/test/functional/autocmd/termclose_spec.lua
@@ -1,11 +1,11 @@
 local helpers = require('test.functional.helpers')
 local Screen = require('test.functional.ui.screen')
 
-local clear, eval, execute, feed, nvim, nvim_dir = helpers.clear, helpers.eval,
+local clear, execute, feed, nvim, nvim_dir = helpers.clear,
 helpers.execute, helpers.feed, helpers.nvim, helpers.nvim_dir
-local wait = helpers.wait
 
 describe('TermClose event', function()
+  local screen
   before_each(function()
     clear()
     nvim('set_option', 'shell', nvim_dir .. '/shell-test')
diff --git a/test/functional/clipboard/clipboard_provider_spec.lua b/test/functional/clipboard/clipboard_provider_spec.lua
index 98b8d2dd45..898ec556a2 100644
--- a/test/functional/clipboard/clipboard_provider_spec.lua
+++ b/test/functional/clipboard/clipboard_provider_spec.lua
@@ -4,7 +4,6 @@ local helpers = require('test.functional.helpers')
 local Screen = require('test.functional.ui.screen')
 local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
 local execute, expect, eq, eval = helpers.execute, helpers.expect, helpers.eq, helpers.eval
-local nvim, run, stop, restart = helpers.nvim, helpers.run, helpers.stop, helpers.restart
 
 local function basic_register_test(noblock)
   insert("some words")
diff --git a/test/functional/eval/glob_spec.lua b/test/functional/eval/glob_spec.lua
index f99a9e7d0e..c6bba46424 100644
--- a/test/functional/eval/glob_spec.lua
+++ b/test/functional/eval/glob_spec.lua
@@ -1,3 +1,4 @@
+local lfs = require('lfs')
 local helpers = require('test.functional.helpers')
 local clear, execute, eval, eq = helpers.clear, helpers.execute, helpers.eval, helpers.eq
 
diff --git a/test/functional/eval/msgpack_functions_spec.lua b/test/functional/eval/msgpack_functions_spec.lua
index 9a7b630f64..da42fc9d26 100644
--- a/test/functional/eval/msgpack_functions_spec.lua
+++ b/test/functional/eval/msgpack_functions_spec.lua
@@ -1,7 +1,7 @@
 local helpers = require('test.functional.helpers')
-local clear, feed, execute = helpers.clear, helpers.feed, helpers.execute
-local eval, eq, neq = helpers.eval, helpers.eq, helpers.neq
-local execute, source = helpers.execute, helpers.source
+local clear = helpers.clear
+local eval, eq = helpers.eval, helpers.eq
+local execute = helpers.execute
 local nvim = helpers.nvim
 local exc_exec = helpers.exc_exec
 
@@ -454,9 +454,9 @@ describe('msgpackparse() function', function()
   it('msgpackparse(systemlist(...)) does not segfault. #3135', function()
     local cmd = "sort(keys(msgpackparse(systemlist('"
       ..helpers.nvim_prog.." --api-info'))[0]))"
-    local api_info = eval(cmd)
-    api_info = eval(cmd) -- do it again (try to force segfault)
-    api_info = eval(cmd) -- do it again
+    eval(cmd)
+    eval(cmd)  -- do it again (try to force segfault)
+    local api_info = eval(cmd)  -- do it again
     eq({'error_types', 'functions', 'types'}, api_info)
   end)
 
diff --git a/test/functional/ex_cmds/grep_spec.lua b/test/functional/ex_cmds/grep_spec.lua
index 9c792099c1..f3ff0a3817 100644
--- a/test/functional/ex_cmds/grep_spec.lua
+++ b/test/functional/ex_cmds/grep_spec.lua
@@ -1,7 +1,6 @@
 local helpers = require('test.functional.helpers')
-local clear, execute, nvim, feed, eq, ok, eval =
-  helpers.clear, helpers.execute, helpers.nvim, helpers.feed,
-  helpers.eq, helpers.ok, helpers.eval
+local clear, execute, feed, ok, eval =
+  helpers.clear, helpers.execute, helpers.feed, helpers.ok, helpers.eval
 
 describe(':grep', function()
   before_each(clear)
diff --git a/test/functional/ex_cmds/oldfiles_spec.lua b/test/functional/ex_cmds/oldfiles_spec.lua
index e02f42cd12..dac6757a97 100644
--- a/test/functional/ex_cmds/oldfiles_spec.lua
+++ b/test/functional/ex_cmds/oldfiles_spec.lua
@@ -2,7 +2,7 @@ local Screen = require('test.functional.ui.screen')
 local helpers = require('test.functional.helpers')
 
 local buf, eq, execute = helpers.curbufmeths, helpers.eq, helpers.execute
-local feed, nvim, nvim_prog = helpers.feed, helpers.nvim, helpers.nvim_prog
+local feed, nvim_prog = helpers.feed, helpers.nvim_prog
 local ok, set_session, spawn = helpers.ok, helpers.set_session, helpers.spawn
 
 local shada_file = 'test.shada'
@@ -11,9 +11,6 @@ local shada_file = 'test.shada'
 -- helpers.clear() uses "-i NONE", which is not useful for this test.
 --
 local function _clear()
-  if session then
-    session:exit(0)
-  end
   set_session(spawn({nvim_prog,
                      '-u', 'NONE',
                      '--cmd', 'set noswapfile undodir=. directory=. viewdir=. backupdir=.',
@@ -32,7 +29,7 @@ describe(':oldfiles', function()
   end
 
   it('shows most recently used files', function()
-    screen = Screen.new(100, 5)
+    local screen = Screen.new(100, 5)
     screen:attach()
     execute('edit testfile1')
     execute('edit testfile2')
diff --git a/test/functional/ex_cmds/profile_spec.lua b/test/functional/ex_cmds/profile_spec.lua
index 721669e73b..744b22621f 100644
--- a/test/functional/ex_cmds/profile_spec.lua
+++ b/test/functional/ex_cmds/profile_spec.lua
@@ -1,5 +1,5 @@
 require('os')
-require('lfs')
+local lfs = require('lfs')
 
 local helpers  = require('test.functional.helpers')
 local eval     = helpers.eval
diff --git a/test/functional/ex_cmds/quit_spec.lua b/test/functional/ex_cmds/quit_spec.lua
index 3cd8e19617..a8156228d3 100644
--- a/test/functional/ex_cmds/quit_spec.lua
+++ b/test/functional/ex_cmds/quit_spec.lua
@@ -1,5 +1,5 @@
 local helpers = require('test.functional.helpers')
-local execute, eq, clear = helpers.execute, helpers.eq, helpers.clear
+local clear = helpers.clear
 
 describe(':qa', function()
   before_each(function() 
diff --git a/test/functional/ex_cmds/recover_spec.lua b/test/functional/ex_cmds/recover_spec.lua
index 6749cfaf40..e1d01f6896 100644
--- a/test/functional/ex_cmds/recover_spec.lua
+++ b/test/functional/ex_cmds/recover_spec.lua
@@ -1,6 +1,7 @@
 -- Tests for :recover
 
 local helpers = require('test.functional.helpers')
+local lfs = require('lfs')
 local execute, eq, clear, eval, feed, expect, source =
   helpers.execute, helpers.eq, helpers.clear, helpers.eval, helpers.feed,
   helpers.expect, helpers.source
diff --git a/test/functional/ex_cmds/sign_spec.lua b/test/functional/ex_cmds/sign_spec.lua
index be213cd0d9..c50704504d 100644
--- a/test/functional/ex_cmds/sign_spec.lua
+++ b/test/functional/ex_cmds/sign_spec.lua
@@ -1,7 +1,5 @@
 local helpers = require('test.functional.helpers')
-local clear, nvim, buffer, curbuf, curwin, eq, ok =
-  helpers.clear, helpers.nvim, helpers.buffer, helpers.curbuf, helpers.curwin,
-  helpers.eq, helpers.ok
+local clear, nvim, eq = helpers.clear, helpers.nvim, helpers.eq
 
 describe('sign', function()
   before_each(clear)
diff --git a/test/functional/ex_cmds/wviminfo_spec.lua b/test/functional/ex_cmds/wviminfo_spec.lua
index b6b9185cf2..207d94124f 100644
--- a/test/functional/ex_cmds/wviminfo_spec.lua
+++ b/test/functional/ex_cmds/wviminfo_spec.lua
@@ -1,6 +1,6 @@
 local helpers, lfs = require('test.functional.helpers'), require('lfs')
-local clear, execute, eq, neq, spawn, nvim_prog, set_session, wait, write_file
-  = helpers.clear, helpers.execute, helpers.eq, helpers.neq, helpers.spawn,
+local execute, eq, neq, spawn, nvim_prog, set_session, wait, write_file
+  = helpers.execute, helpers.eq, helpers.neq, helpers.spawn,
   helpers.nvim_prog, helpers.set_session, helpers.wait, helpers.write_file
 
 describe(':wshada', function()
@@ -13,7 +13,7 @@ describe(':wshada', function()
     end
 
     -- Override the default session because we need 'swapfile' for these tests.
-    local session = spawn({nvim_prog, '-u', 'NONE', '-i', '/dev/null', '--embed',
+    session = spawn({nvim_prog, '-u', 'NONE', '-i', '/dev/null', '--embed',
                            '--cmd', 'set swapfile'})
     set_session(session)
 
diff --git a/test/functional/helpers.lua b/test/functional/helpers.lua
index 8a85f187cf..9562457c8e 100644
--- a/test/functional/helpers.lua
+++ b/test/functional/helpers.lua
@@ -1,4 +1,5 @@
 require('coxpcall')
+local lfs = require('lfs')
 local assert = require('luassert')
 local Loop = require('nvim.loop')
 local MsgpackStream = require('nvim.msgpack_stream')
@@ -55,7 +56,7 @@ if prepend_argv then
   nvim_argv = new_nvim_argv
 end
 
-local session, loop_running, loop_stopped, last_error
+local session, loop_running, last_error
 
 local function set_session(s)
   session = s
@@ -79,7 +80,7 @@ local function next_message()
 end
 
 local function call_and_stop_on_error(...)
-  local status, result = copcall(...)
+  local status, result = copcall(...)  -- luacheck: ignore
   if not status then
     session:stop()
     last_error = result
@@ -109,7 +110,6 @@ local function run(request_cb, notification_cb, setup_cb, timeout)
     end
   end
 
-  loop_stopped = false
   loop_running = true
   session:run(on_request, on_notification, on_setup, timeout)
   loop_running = false
@@ -121,7 +121,6 @@ local function run(request_cb, notification_cb, setup_cb, timeout)
 end
 
 local function stop()
-  loop_stopped = true
   session:stop()
 end
 
@@ -197,9 +196,9 @@ local function spawn(argv, merge)
   local loop = Loop.new()
   local msgpack_stream = MsgpackStream.new(loop)
   local async_session = AsyncSession.new(msgpack_stream)
-  local session = Session.new(async_session)
+  local sess = Session.new(async_session)
   loop:spawn(merge and merge_args(prepend_argv, argv) or argv)
-  return session
+  return sess
 end
 
 local function clear(extra_cmd)
@@ -332,14 +331,14 @@ local function rmdir(path)
     if file == '.' or file == '..' then
       goto continue
     end
-    ret, err = os.remove(path..'/'..file)
+    local ret, err = os.remove(path..'/'..file)
     if not ret then
       error('os.remove: '..err)
       return nil
     end
     ::continue::
   end
-  ret, err = os.remove(path)
+  local ret, err = os.remove(path)
   if not ret then
     error('os.remove: '..err)
   end
@@ -371,15 +370,15 @@ local function redir_exec(cmd)
 end
 
 local function create_callindex(func)
-  local tbl = {}
-  setmetatable(tbl, {
+  local table = {}
+  setmetatable(table, {
     __index = function(tbl, arg1)
-      ret = function(...) return func(arg1, ...) end
+      local ret = function(...) return func(arg1, ...) end
       tbl[arg1] = ret
       return ret
     end,
   })
-  return tbl
+  return table
 end
 
 local funcs = create_callindex(nvim_call)
diff --git a/test/functional/job/job_spec.lua b/test/functional/job/job_spec.lua
index bdaf2a7ec6..0915ab0955 100644
--- a/test/functional/job/job_spec.lua
+++ b/test/functional/job/job_spec.lua
@@ -1,11 +1,11 @@
 
 local helpers = require('test.functional.helpers')
-local clear, eq, eval, execute, expect, feed, insert, neq, next_msg, nvim,
-  nvim_dir, ok, run, session, source, stop, wait, write_file = helpers.clear,
-  helpers.eq, helpers.eval, helpers.execute, helpers.expect, helpers.feed,
+local clear, eq, eval, execute, feed, insert, neq, next_msg, nvim,
+  nvim_dir, ok, source, write_file = helpers.clear,
+  helpers.eq, helpers.eval, helpers.execute, helpers.feed,
   helpers.insert, helpers.neq, helpers.next_message, helpers.nvim,
-  helpers.nvim_dir, helpers.ok, helpers.run, helpers.session, helpers.source,
-  helpers.stop, helpers.wait, helpers.write_file
+  helpers.nvim_dir, helpers.ok, helpers.source,
+  helpers.write_file
 local Screen = require('test.functional.ui.screen')
 
 
@@ -370,7 +370,7 @@ describe('jobs', function()
 
   describe('running tty-test program', function()
     local function next_chunk()
-      local rv = ''
+      local rv
       while true do
         local msg = next_msg()
         local data = msg[3][2]
diff --git a/test/functional/legacy/003_cindent_spec.lua b/test/functional/legacy/003_cindent_spec.lua
index 1857721563..39de3e8280 100644
--- a/test/functional/legacy/003_cindent_spec.lua
+++ b/test/functional/legacy/003_cindent_spec.lua
@@ -4,7 +4,7 @@
 -- in the original test. These have been converted to "it" test cases here.
 
 local helpers = require('test.functional.helpers')
-local feed, insert, source = helpers.feed, helpers.insert, helpers.source
+local feed, insert = helpers.feed, helpers.insert
 local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
 
 -- Inserts text as usual, and additionally positions the cursor on line 1 and
diff --git a/test/functional/legacy/009_bufleave_autocommand_spec.lua b/test/functional/legacy/009_bufleave_autocommand_spec.lua
index 0fc1b5b657..8c18639c8f 100644
--- a/test/functional/legacy/009_bufleave_autocommand_spec.lua
+++ b/test/functional/legacy/009_bufleave_autocommand_spec.lua
@@ -1,7 +1,7 @@
 -- Test for Bufleave autocommand that deletes the buffer we are about to edit.
 
 local helpers = require('test.functional.helpers')
-local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
+local clear, insert = helpers.clear, helpers.insert
 local execute, expect = helpers.execute, helpers.expect
 
 describe('BufLeave autocommand', function()
diff --git a/test/functional/legacy/015_alignment_spec.lua b/test/functional/legacy/015_alignment_spec.lua
index e71f9d1c90..3b19f4ff42 100644
--- a/test/functional/legacy/015_alignment_spec.lua
+++ b/test/functional/legacy/015_alignment_spec.lua
@@ -3,7 +3,7 @@
 -- Also test undo after ":%s" and formatting.
 
 local helpers = require('test.functional.helpers')
-local feed, insert, source = helpers.feed, helpers.insert, helpers.source
+local feed, insert = helpers.feed, helpers.insert
 local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
 
 describe('alignment', function()
diff --git a/test/functional/legacy/022_line_ending_spec.lua b/test/functional/legacy/022_line_ending_spec.lua
index 4b897a7c95..a841378a82 100644
--- a/test/functional/legacy/022_line_ending_spec.lua
+++ b/test/functional/legacy/022_line_ending_spec.lua
@@ -1,7 +1,7 @@
 -- Tests for file with some lines ending in CTRL-M, some not
 
 local helpers = require('test.functional.helpers')
-local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
+local clear, feed = helpers.clear, helpers.feed
 local execute, expect = helpers.execute, helpers.expect
 
 describe('line ending', function()
diff --git a/test/functional/legacy/023_edit_arguments_spec.lua b/test/functional/legacy/023_edit_arguments_spec.lua
index e68af9758d..15b30bfa3a 100644
--- a/test/functional/legacy/023_edit_arguments_spec.lua
+++ b/test/functional/legacy/023_edit_arguments_spec.lua
@@ -1,7 +1,7 @@
 -- Tests for complicated + argument to :edit command
 
 local helpers = require('test.functional.helpers')
-local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
+local clear, insert = helpers.clear, helpers.insert
 local execute, expect = helpers.execute, helpers.expect
 
 describe(':edit', function()
diff --git a/test/functional/legacy/026_execute_while_if_spec.lua b/test/functional/legacy/026_execute_while_if_spec.lua
index ffe37819de..f17bb79702 100644
--- a/test/functional/legacy/026_execute_while_if_spec.lua
+++ b/test/functional/legacy/026_execute_while_if_spec.lua
@@ -1,7 +1,7 @@
 -- Test for :execute, :while and :if
 
 local helpers = require('test.functional.helpers')
-local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
+local clear = helpers.clear
 local execute, expect = helpers.execute, helpers.expect
 local source = helpers.source
 
diff --git a/test/functional/legacy/027_expand_file_names_spec.lua b/test/functional/legacy/027_expand_file_names_spec.lua
index d31f29d38a..4778d16d43 100644
--- a/test/functional/legacy/027_expand_file_names_spec.lua
+++ b/test/functional/legacy/027_expand_file_names_spec.lua
@@ -1,10 +1,10 @@
 -- Test for expanding file names
 
 local helpers = require('test.functional.helpers')
-local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
-local execute, expect = helpers.execute, helpers.expect
+local clear, feed = helpers.clear, helpers.feed
+local execute = helpers.execute
 local curbuf_contents = helpers.curbuf_contents
-local eq, eval = helpers.eq, helpers.eval
+local eq = helpers.eq
 
 describe('expand file name', function()
   setup(clear)
diff --git a/test/functional/legacy/029_join_spec.lua b/test/functional/legacy/029_join_spec.lua
index eafa50d88c..25a072ad6e 100644
--- a/test/functional/legacy/029_join_spec.lua
+++ b/test/functional/legacy/029_join_spec.lua
@@ -1,7 +1,7 @@
 -- Test for joining lines with marks in them (and with 'joinspaces' set/reset)
 
 local helpers = require('test.functional.helpers')
-local feed, insert, source = helpers.feed, helpers.insert, helpers.source
+local feed, insert = helpers.feed, helpers.insert
 local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
 
 describe('joining lines', function()
diff --git a/test/functional/legacy/031_close_commands_spec.lua b/test/functional/legacy/031_close_commands_spec.lua
index 78e71b5fb1..3597cba12a 100644
--- a/test/functional/legacy/031_close_commands_spec.lua
+++ b/test/functional/legacy/031_close_commands_spec.lua
@@ -10,7 +10,7 @@
 -- :edit
 
 local helpers = require('test.functional.helpers')
-local feed, insert, source = helpers.feed, helpers.insert, helpers.source
+local feed, insert = helpers.feed, helpers.insert
 local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
 
 describe('Commands that close windows and/or buffers', function()
diff --git a/test/functional/legacy/038_virtual_replace_spec.lua b/test/functional/legacy/038_virtual_replace_spec.lua
index 94503bd42a..10d42f0cea 100644
--- a/test/functional/legacy/038_virtual_replace_spec.lua
+++ b/test/functional/legacy/038_virtual_replace_spec.lua
@@ -1,7 +1,7 @@
 -- Test Virtual replace mode.
 
 local helpers = require('test.functional.helpers')
-local feed, insert, source = helpers.feed, helpers.insert, helpers.source
+local feed = helpers.feed
 local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
 
 describe('Virtual replace mode', function()
diff --git a/test/functional/legacy/044_099_regexp_multibyte_magic_spec.lua b/test/functional/legacy/044_099_regexp_multibyte_magic_spec.lua
index efe61aa354..1359b45228 100644
--- a/test/functional/legacy/044_099_regexp_multibyte_magic_spec.lua
+++ b/test/functional/legacy/044_099_regexp_multibyte_magic_spec.lua
@@ -4,7 +4,7 @@
 -- This test contains both "test44" and "test99" from the old test suite.
 
 local helpers = require('test.functional.helpers')
-local feed, insert, source = helpers.feed, helpers.insert, helpers.source
+local feed, insert = helpers.feed, helpers.insert
 local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
 
 -- Runs the test protocol with the given 'regexpengine' setting. In the old test
diff --git a/test/functional/legacy/046_multi_line_regexps_spec.lua b/test/functional/legacy/046_multi_line_regexps_spec.lua
index f8a6143b18..b17ab42fe3 100644
--- a/test/functional/legacy/046_multi_line_regexps_spec.lua
+++ b/test/functional/legacy/046_multi_line_regexps_spec.lua
@@ -3,7 +3,7 @@
 
 local helpers = require('test.functional.helpers')
 local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
-local execute, expect = helpers.execute, helpers.expect
+local expect = helpers.expect
 
 describe('multi-line regexp', function()
   setup(clear)
diff --git a/test/functional/legacy/051_highlight_spec.lua b/test/functional/legacy/051_highlight_spec.lua
index 620df97aac..94c42b73e5 100644
--- a/test/functional/legacy/051_highlight_spec.lua
+++ b/test/functional/legacy/051_highlight_spec.lua
@@ -3,7 +3,7 @@
 
 local Screen = require('test.functional.ui.screen')
 local helpers = require('test.functional.helpers')
-local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
+local clear, feed = helpers.clear, helpers.feed
 local execute, expect = helpers.execute, helpers.expect
 local wait = helpers.wait
 
diff --git a/test/functional/legacy/056_script_local_function_spec.lua b/test/functional/legacy/056_script_local_function_spec.lua
index 147391ceb1..dec88e8001 100644
--- a/test/functional/legacy/056_script_local_function_spec.lua
+++ b/test/functional/legacy/056_script_local_function_spec.lua
@@ -3,7 +3,7 @@
 
 local helpers = require('test.functional.helpers')
 local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
-local execute, expect = helpers.execute, helpers.expect
+local expect = helpers.expect
 
 describe('source function', function()
   setup(clear)
diff --git a/test/functional/legacy/060_exists_and_has_functions_spec.lua b/test/functional/legacy/060_exists_and_has_functions_spec.lua
index e9b79b490d..7f44b35a4e 100644
--- a/test/functional/legacy/060_exists_and_has_functions_spec.lua
+++ b/test/functional/legacy/060_exists_and_has_functions_spec.lua
@@ -1,8 +1,8 @@
 -- Tests for the exists() and has() functions.
 
 local helpers = require('test.functional.helpers')
-local feed, insert, source = helpers.feed, helpers.insert, helpers.source
-local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
+local source = helpers.source
+local clear, expect = helpers.clear, helpers.expect
 local write_file = helpers.write_file
 
 describe('exists() and has() functions', function()
diff --git a/test/functional/legacy/061_undo_tree_spec.lua b/test/functional/legacy/061_undo_tree_spec.lua
index 8cc2a371bb..ceb114b2a7 100644
--- a/test/functional/legacy/061_undo_tree_spec.lua
+++ b/test/functional/legacy/061_undo_tree_spec.lua
@@ -1,8 +1,8 @@
 -- Tests for undo tree and :earlier and :later.
 
 local helpers = require('test.functional.helpers')
-local feed, insert, source, eq, eval, clear, execute, expect, wait, write_file
-  = helpers.feed, helpers.insert, helpers.source, helpers.eq, helpers.eval,
+local feed, source, eq, eval, clear, execute, expect, wait, write_file =
+  helpers.feed, helpers.source, helpers.eq, helpers.eval,
   helpers.clear, helpers.execute, helpers.expect, helpers.wait,
   helpers.write_file
 
@@ -97,9 +97,8 @@ describe('undo tree:', function()
 
       -- Retry up to 3 times. pcall() is _not_ used for the final attempt, so
       -- that failure messages can bubble up.
-      local success, result = false, ''
-      for i = 1, 2 do
-        success, result = pcall(test_earlier_later)
+      for _ = 1, 2 do
+        local success = pcall(test_earlier_later)
         if success then
           return
         end
diff --git a/test/functional/legacy/063_match_and_matchadd_spec.lua b/test/functional/legacy/063_match_and_matchadd_spec.lua
index d819db7812..a354d4d328 100644
--- a/test/functional/legacy/063_match_and_matchadd_spec.lua
+++ b/test/functional/legacy/063_match_and_matchadd_spec.lua
@@ -2,10 +2,9 @@
 
 local helpers = require('test.functional.helpers')
 local Screen = require('test.functional.ui.screen')
-local feed, insert, source = helpers.feed, helpers.insert, helpers.source
-local eval, clear, execute, expect = helpers.eval, helpers.clear, helpers.execute
-local expect, eq, neq = helpers.expect, helpers.eq, helpers.neq
-local command = helpers.command
+local feed, insert = helpers.feed, helpers.insert
+local eval, clear, execute = helpers.eval, helpers.clear, helpers.execute
+local eq, neq = helpers.eq, helpers.neq
 
 describe('063: Test for ":match", "matchadd()" and related functions', function()
   setup(clear)
@@ -86,7 +85,7 @@ describe('063: Test for ":match", "matchadd()" and related functions', function(
     execute("2match MyGroup2 /HUMPPA/")
     execute("3match MyGroup3 /VIM/")
     execute("let ml = getmatches()")
-    ml = eval("ml")
+    local ml = eval("ml")
     execute("call clearmatches()")
     execute("call setmatches(ml)")
     eq(ml, eval('getmatches()'))
diff --git a/test/functional/legacy/065_float_and_logic_operators_spec.lua b/test/functional/legacy/065_float_and_logic_operators_spec.lua
index 5cdb0b7f58..e78b230956 100644
--- a/test/functional/legacy/065_float_and_logic_operators_spec.lua
+++ b/test/functional/legacy/065_float_and_logic_operators_spec.lua
@@ -1,7 +1,7 @@
 -- Test for floating point and logical operators.
 
 local helpers = require('test.functional.helpers')
-local feed, insert, source = helpers.feed, helpers.insert, helpers.source
+local insert, source = helpers.insert, helpers.source
 local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
 
 describe('floating point and logical operators', function()
diff --git a/test/functional/legacy/067_augroup_exists_spec.lua b/test/functional/legacy/067_augroup_exists_spec.lua
index 6d89ad6d55..dc4c9c7eeb 100644
--- a/test/functional/legacy/067_augroup_exists_spec.lua
+++ b/test/functional/legacy/067_augroup_exists_spec.lua
@@ -2,7 +2,7 @@
 -- autocommands.
 
 local helpers = require('test.functional.helpers')
-local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
+local clear = helpers.clear
 local execute, expect = helpers.execute, helpers.expect
 
 describe('augroup when calling exists()', function()
diff --git a/test/functional/legacy/072_undo_file_spec.lua b/test/functional/legacy/072_undo_file_spec.lua
index ce9129ff43..efcc2f2cc3 100644
--- a/test/functional/legacy/072_undo_file_spec.lua
+++ b/test/functional/legacy/072_undo_file_spec.lua
@@ -3,7 +3,7 @@
 -- undo-able pieces.  Do that by setting 'undolevels'.
 
 local helpers = require('test.functional.helpers')
-local feed, insert, source = helpers.feed, helpers.insert, helpers.source
+local feed, insert = helpers.feed, helpers.insert
 local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
 
 describe('72', function()
diff --git a/test/functional/legacy/074_global_var_in_viminfo_spec.lua b/test/functional/legacy/074_global_var_in_viminfo_spec.lua
index 2428b7f74d..49c4827613 100644
--- a/test/functional/legacy/074_global_var_in_viminfo_spec.lua
+++ b/test/functional/legacy/074_global_var_in_viminfo_spec.lua
@@ -13,7 +13,7 @@ describe('storing global variables in ShaDa files', function()
   end)
 
   it('is working', function()
-    local nvim2 = helpers.spawn({helpers.nvim_prog, '-u', 'NONE',
+    local nvim2 = spawn({helpers.nvim_prog, '-u', 'NONE',
                                  '-i', 'Xviminfo', '--embed'})
     helpers.set_session(nvim2)
 
diff --git a/test/functional/legacy/075_maparg_spec.lua b/test/functional/legacy/075_maparg_spec.lua
index 418abb14d4..82965f5cb2 100644
--- a/test/functional/legacy/075_maparg_spec.lua
+++ b/test/functional/legacy/075_maparg_spec.lua
@@ -2,7 +2,7 @@
 -- Also test utf8 map with a 0x80 byte.
 
 local helpers = require('test.functional.helpers')
-local clear, feed, insert = helpers.clear, helpers.feed, helpers.insert
+local clear, feed = helpers.clear, helpers.feed
 local execute, expect = helpers.execute, helpers.expect
 
 describe('maparg()', function()
diff --git a/test/functional/legacy/077_mf_hash_grow_spec.lua b/test/functional/legacy/077_mf_hash_grow_spec.lua
index 825f08e968..029fe98fe9 100644
--- a/test/functional/legacy/077_mf_hash_grow_spec.lua
+++ b/test/functional/legacy/077_mf_hash_grow_spec.lua
@@ -7,7 +7,7 @@
 -- If it isn't available then the test will be skipped.
 
 local helpers = require('test.functional.helpers')
-local feed, insert, source = helpers.feed, helpers.insert, helpers.source
+local feed = helpers.feed
 local clear, execute, expect = helpers.clear, helpers.execute, helpers.expect
 
 describe('mf_hash_grow()', function()
diff --git a/test/functional/legacy/078_swapfile_recover_spec.lua b/test/functional/legacy/078_swapfile_recover_spec.lua
index 21a3dadefd..e48fddaac1 100644
--- a/test/functional/legacy/078_swapfile_recover_spec.lua
+++ b/test/functional/legacy/078_swapfile_recover_spec.lua
@@ -5,7 +5,6 @@
 
 local helpers = require('test.functional.helpers')
 local clear, expect, source = helpers.clear, helpers.expect, helpers.source
-local eval = helpers.eval
 
 describe('78', function()
   setup(clear)
diff --git a/test/functional/plugin/helpers.lua b/test/functional/plugin/helpers.lua
index 9762ca314e..cc76794267 100644
--- a/test/functional/plugin/helpers.lua
+++ b/test/functional/plugin/helpers.lua
@@ -9,15 +9,15 @@ local additional_cmd = ''
 local function nvim_argv(shada_file)
   local rtp_value = ('\'%s/runtime\''):format(
       paths.test_source_path:gsub('\'', '\'\''))
-  local nvim_argv = {nvim_prog, '-u', 'NORC', '-i', shada_file or 'NONE', '-N',
+  local nvim_args = {nvim_prog, '-u', 'NORC', '-i', shada_file or 'NONE', '-N',
                      '--cmd', 'set shortmess+=I background=light noswapfile',
                      '--cmd', 'let &runtimepath=' .. rtp_value,
                      '--cmd', additional_cmd,
                      '--embed'}
   if helpers.prepend_argv then
-    return merge_args(helpers.prepend_argv, nvim_argv)
+    return merge_args(helpers.prepend_argv, nvim_args)
   else
-    return nvim_argv
+    return nvim_args
   end
 end
 
diff --git a/test/functional/plugin/shada_spec.lua b/test/functional/plugin/shada_spec.lua
index 407f13a55b..2202f60ce8 100644
--- a/test/functional/plugin/shada_spec.lua
+++ b/test/functional/plugin/shada_spec.lua
@@ -11,7 +11,6 @@ local reset = plugin_helpers.reset
 
 local shada_helpers = require('test.functional.shada.helpers')
 local get_shada_rw = shada_helpers.get_shada_rw
-local read_shada_file = shada_helpers.read_shada_file
 
 local mpack_eq = function(expected, mpack_result)
   local mpack_keys = {'type', 'timestamp', 'length', 'value'}
@@ -96,10 +95,10 @@ describe('In autoload/shada.vim', function()
         return a[1] < b[1]
       end)
       local state = {i=0}
-      return (function(state, var)
-        state.i = state.i + 1
-        if ret[state.i] then
-          return table.unpack(ret[state.i])
+      return (function(state_, _)
+        state_.i = state_.i + 1
+        if ret[state_.i] then
+          return table.unpack(ret[state_.i])
         end
       end), state
     end
@@ -2103,8 +2102,8 @@ describe('In plugin/shada.vim', function()
     os.remove(fname_tmp)
   end)
 
-  local shada_eq = function(expected, fname)
-    local fd = io.open(fname)
+  local shada_eq = function(expected, fname_)
+    local fd = io.open(fname_)
     local mpack_result = fd:read('*a')
     fd:close()
     mpack_eq(expected, mpack_result)
@@ -2574,6 +2573,7 @@ describe('syntax/shada.vim', function()
                                      'ShaDaEntryMapHeader'}, s} end
     local ah = function(s) return {{'ShaDaEntryArray',
                                     'ShaDaEntryArrayHeader'}, s} end
+    -- luacheck: ignore
     local mses = function(s) return {{'ShaDaEntryMapShort',
                                       'ShaDaEntryMapShortEntryStart'}, s} end
     local mles = function(s) return {{'ShaDaEntryMapLong',
diff --git a/test/functional/terminal/tui_spec.lua b/test/functional/terminal/tui_spec.lua
index 0ace24ee0f..14700a2622 100644
--- a/test/functional/terminal/tui_spec.lua
+++ b/test/functional/terminal/tui_spec.lua
@@ -175,6 +175,8 @@ describe('tui with non-tty file descriptors', function()
 end)
 
 describe('tui focus event handling', function()
+  local screen
+
   before_each(function()
     helpers.clear()
     screen = thelpers.screen_setup(0, '["'..helpers.nvim_prog..'", "-u", "NONE", "-i", "NONE", "--cmd", "set noswapfile"]')
diff --git a/test/functional/ui/screen.lua b/test/functional/ui/screen.lua
index c8250ec4c1..e1c2d14759 100644
--- a/test/functional/ui/screen.lua
+++ b/test/functional/ui/screen.lua
@@ -106,7 +106,7 @@
 -- use `screen:snapshot_util({},true)`
 
 local helpers = require('test.functional.helpers')
-local request, run, stop = helpers.request, helpers.run, helpers.stop
+local request, run = helpers.request, helpers.run
 local dedent = helpers.dedent
 
 local Screen = {}
@@ -241,7 +241,7 @@ function Screen:wait(check, timeout)
     checked = true
     if not err then
       success_seen = true
-      stop()
+      helpers.stop()
     elseif success_seen and #args > 0 then
       failure_after_success = true
       --print(require('inspect')(args))
@@ -448,7 +448,7 @@ function Screen:_row_repr(row, attr_ids, attr_ignore)
   local rv = {}
   local current_attr_id
   for i = 1, self._width do
-    local attr_id = get_attr_id(attr_ids, attr_ignore, row[i].attrs)
+    local attr_id = self:_get_attr_id(attr_ids, attr_ignore, row[i].attrs)
     if current_attr_id and attr_id ~= current_attr_id then
       -- close current attribute bracket, add it before any whitespace
       -- up to the current cell
@@ -524,8 +524,8 @@ function Screen:print_snapshot(attrs, ignore)
         local row = self._rows[i]
         for j = 1, self._width do
           local attr = row[j].attrs
-          if attr_index(attrs, attr) == nil and attr_index(ignore, attr) == nil then
-            if not equal_attrs(attr, {}) then
+          if self:_attr_index(attrs, attr) == nil and self:_attr_index(ignore, attr) == nil then
+            if not self:_equal_attrs(attr, {}) then
               table.insert(attrs, attr)
             end
           end
@@ -544,7 +544,7 @@ function Screen:print_snapshot(attrs, ignore)
     if self._default_attr_ids == nil or self._default_attr_ids[i] ~= a then
       alldefault = false
     end
-    local dict = "{"..pprint_attrs(a).."}"
+    local dict = "{"..self:_pprint_attrs(a).."}"
     table.insert(attrstrs, "["..tostring(i).."] = "..dict)
   end
   local attrstr = "{"..table.concat(attrstrs, ", ").."}"
@@ -558,7 +558,7 @@ function Screen:print_snapshot(attrs, ignore)
   io.stdout:flush()
 end
 
-function pprint_attrs(attrs)
+function Screen:_pprint_attrs(attrs)
     local items = {}
     for f, v in pairs(attrs) do
       local desc = tostring(v)
@@ -572,7 +572,7 @@ function pprint_attrs(attrs)
     return table.concat(items, ", ")
 end
 
-function backward_find_meaningful(tbl, from)
+function backward_find_meaningful(tbl, from)  -- luacheck: ignore
   for i = from or #tbl, 1, -1 do
     if tbl[i] ~= ' ' then
       return i + 1
@@ -581,24 +581,24 @@ function backward_find_meaningful(tbl, from)
   return from
 end
 
-function get_attr_id(attr_ids, ignore, attrs)
+function Screen:_get_attr_id(attr_ids, ignore, attrs)
   if not attr_ids then
     return
   end
   for id, a in pairs(attr_ids) do
-    if equal_attrs(a, attrs) then
+    if self:_equal_attrs(a, attrs) then
        return id
      end
   end
-  if equal_attrs(attrs, {}) or
-      ignore == true or attr_index(ignore, attrs) ~= nil then
+  if self:_equal_attrs(attrs, {}) or
+      ignore == true or self:_attr_index(ignore, attrs) ~= nil then
     -- ignore this attrs
     return nil
   end
-  return "UNEXPECTED "..pprint_attrs(attrs)
+  return "UNEXPECTED "..self:_pprint_attrs(attrs)
 end
 
-function equal_attrs(a, b)
+function Screen:_equal_attrs(a, b)
     return a.bold == b.bold and a.standout == b.standout and
        a.underline == b.underline and a.undercurl == b.undercurl and
        a.italic == b.italic and a.reverse == b.reverse and
@@ -606,12 +606,12 @@ function equal_attrs(a, b)
        a.background == b.background
 end
 
-function attr_index(attrs, attr)
+function Screen:_attr_index(attrs, attr)
   if not attrs then
     return nil
   end
   for i,a in pairs(attrs) do
-    if equal_attrs(a, attr) then
+    if self:_equal_attrs(a, attr) then
       return i
     end
   end