test: Extend {unit,functional}.helpers with global helpers

Automatically include all "global helper" util functions in the
unit.helpers and functional.helpers and modules.  So tests don't need to
expicitly do:

    local global_helpers = require('test.helpers')

test/functional/api/server_requests_spec.lua

@@ -1,7 +1,6 @@
 -- Test server -> client RPC scenarios. Note: unlike `rpcnotify`, to evaluate
 -- `rpcrequest` calls we need the client event loop to be running.
 local helpers = require('test.functional.helpers')(after_each)
-local Paths = require('test.config.paths')
 
 local clear, nvim, eval = helpers.clear, helpers.nvim, helpers.eval
 local eq, neq, run, stop = helpers.eq, helpers.neq, helpers.run, helpers.stop
@@ -243,8 +242,8 @@ describe('server -> client', function()
         \ 'rpc': v:true
         \ }
       ]])
-      local lua_prog = Paths.test_lua_prg
+      meths.set_var("args", {helpers.test_lua_prg,
-      meths.set_var("args", {lua_prog, 'test/functional/api/rpc_fixture.lua'})
+                             'test/functional/api/rpc_fixture.lua'})
       jobid = eval("jobstart(g:args, g:job_opts)")
       neq(0, 'jobid')
     end)

test/functional/helpers.lua

@@ -8,20 +8,12 @@ local Session = require('nvim.session')
 local TcpStream = require('nvim.tcp_stream')
 local SocketStream = require('nvim.socket_stream')
 local ChildProcessStream = require('nvim.child_process_stream')
-local Paths = require('test.config.paths')
 
 local check_cores = global_helpers.check_cores
 local check_logs = global_helpers.check_logs
 local dedent = global_helpers.dedent
 local eq = global_helpers.eq
-local expect_err = global_helpers.expect_err
-local filter = global_helpers.filter
-local map = global_helpers.map
-local matches = global_helpers.matches
-local near = global_helpers.near
-local neq = global_helpers.neq
 local ok = global_helpers.ok
-local read_file = global_helpers.read_file
 local sleep = global_helpers.sleep
 local table_contains = global_helpers.table_contains
 local table_flatten = global_helpers.table_flatten
@@ -32,7 +24,7 @@ local start_dir = lfs.currentdir()
 local nvim_prog = (
   os.getenv('NVIM_PROG')
   or os.getenv('NVIM_PRG')
-  or Paths.test_build_dir .. '/bin/nvim'
+  or global_helpers.test_build_dir .. '/bin/nvim'
 )
 -- Default settings for the test session.
 local nvim_set  = 'set shortmess+=I background=light noswapfile noautoindent'
@@ -802,33 +794,25 @@ local module = {
   curtabmeths = curtabmeths,
   curwin = curwin,
   curwinmeths = curwinmeths,
-  dedent = dedent,
-  eq = eq,
   eval = nvim_eval,
   exc_exec = exc_exec,
   expect = expect,
   expect_any = expect_any,
-  expect_err = expect_err,
   expect_msg_seq = expect_msg_seq,
   expect_twostreams = expect_twostreams,
   feed = feed,
   feed_command = feed_command,
-  filter = filter,
   funcs = funcs,
   get_pathsep = get_pathsep,
   get_session = get_session,
   insert = insert,
   iswin = iswin,
-  map = map,
-  matches = matches,
   merge_args = merge_args,
   meth_pcall = meth_pcall,
   meths = meths,
   missing_provider = missing_provider,
   mkdir = lfs.mkdir,
   load_adjust = load_adjust,
-  near = near,
-  neq = neq,
   new_pipename = new_pipename,
   next_msg = next_msg,
   nvim = nvim,
@@ -838,13 +822,11 @@ local module = {
   nvim_prog = nvim_prog,
   nvim_prog_abs = nvim_prog_abs,
   nvim_set = nvim_set,
-  ok = ok,
   os_name = os_name,
   pathroot = pathroot,
   pending_win32 = pending_win32,
   prepend_argv = prepend_argv,
   rawfeed = rawfeed,
-  read_file = read_file,
   redir_exec = redir_exec,
   request = request,
   retry = retry,
@@ -854,20 +836,17 @@ local module = {
   set_session = set_session,
   set_shell_powershell = set_shell_powershell,
   skip_fragile = skip_fragile,
-  sleep = sleep,
   source = source,
   spawn = spawn,
   stop = stop,
-  table_flatten = table_flatten,
   tabmeths = tabmeths,
   tabpage = tabpage,
-  tmpname = tmpname,
   uimeths = uimeths,
   wait = wait,
   window = window,
   winmeths = winmeths,
-  write_file = write_file,
 }
+module = global_helpers.map_extend('error', module, global_helpers)
 
 return function(after_each)
   if after_each then

test/helpers.lua

@@ -3,6 +3,7 @@ local assert = require('luassert')
 local luv = require('luv')
 local lfs = require('lfs')
 local relpath = require('pl.path').relpath
+local Paths = require('test.config.paths')
 
 local quote_me = '[^.%w%+%-%@%_%/]' -- complement (needn't quote)
 local function shell_quote(str)
@@ -420,6 +421,7 @@ local function updated(d, d2)
   return d
 end
 
+-- Concat list-like tables.
 local function concat_tables(...)
   local ret = {}
   for i = 1, select('#', ...) do
@@ -433,6 +435,34 @@ local function concat_tables(...)
   return ret
 end
 
+-- Concat map-like tables.
+--
+-- behavior: Decides what to do if a key is found in more than one map:
+--           "error": raise an error
+--           "keep":  skip
+--           "force": set the item again
+local function map_extend(behavior, ...)
+  if (behavior ~= 'error' and behavior ~= 'keep' and behavior ~= 'force') then
+    error('invalid "behavior": '..tostring(behavior))
+  end
+  local ret = {}
+  for i = 1, select('#', ...) do
+    local tbl = select(i, ...)
+    if tbl then
+      for k, v in pairs(tbl) do
+        if behavior ~= 'force' and ret[k] ~= nil then
+          if behavior == 'error' then
+            error('key found in more than one map: '..k)
+          end  -- Else behavior is "keep".
+        else
+          ret[k] = v
+        end
+      end
+    end
+  end
+  return ret
+end
+
 local function dedent(str, leave_indent)
   -- find minimum common indent across lines
   local indent = nil
@@ -771,6 +801,7 @@ local module = {
   intchar2lua = intchar2lua,
   isCI = isCI,
   map = map,
+  map_extend = map_extend,
   matches = matches,
   mergedicts_copy = mergedicts_copy,
   near = near,
@@ -792,5 +823,6 @@ local module = {
   which = which,
   write_file = write_file,
 }
+module = map_extend('error', module, Paths)
 
 return module

test/unit/helpers.lua

@@ -15,7 +15,6 @@ local dedent = global_helpers.dedent
 local neq = global_helpers.neq
 local map = global_helpers.map
 local eq = global_helpers.eq
-local ok = global_helpers.ok
 
 -- C constants.
 local NULL = ffi.cast('void*', 0)
@@ -842,9 +841,6 @@ local module = {
   cimport = cimport,
   cppimport = cppimport,
   internalize = internalize,
-  ok = ok,
-  eq = eq,
-  neq = neq,
   ffi = ffi,
   lib = lib,
   cstr = cstr,
@@ -869,6 +865,7 @@ local module = {
   ptr2key = ptr2key,
   debug_log = debug_log,
 }
+module = global_helpers.map_extend('error', module, global_helpers)
 return function()
   return module
 end