patch 8.0.1776: in tests, when WaitFor() fails it doesn't say why

Problem:    In tests, when WaitFor() fails it doesn't say why.
Solution:   Turn a few more WaitFor() into WaitForAssert().

5 files changed, 63 insertions, 81 deletions

diff --git a/src/testdir/test_popup.vim b/src/testdir/test_popup.vim
index ed3198585..d682dd211 100644
--- a/src/testdir/test_popup.vim
+++ b/src/testdir/test_popup.vim
@@ -649,18 +649,15 @@ func Test_popup_and_window_resize()
   call term_sendkeys(buf, "\<c-v>")
   call term_wait(buf, 100)
   " popup first entry "!" must be at the top
-  call WaitFor({-> term_getline(buf, 1) =~ "^!"})
-  call assert_match('^!\s*$', term_getline(buf, 1))
+  call WaitForAssert({-> assert_match('^!\s*$', term_getline(buf, 1))})
   exe 'resize +' . (h - 1)
   call term_wait(buf, 100)
   redraw!
   " popup shifted down, first line is now empty
-  call WaitFor({-> term_getline(buf, 1) == ""})
-  call assert_equal('', term_getline(buf, 1))
+  call WaitForAssert({-> assert_equal('', term_getline(buf, 1))})
   sleep 100m
   " popup is below cursor line and shows first match "!"
-  call WaitFor({-> term_getline(buf, term_getcursor(buf)[0] + 1) =~ "^!"})
-  call assert_match('^!\s*$', term_getline(buf, term_getcursor(buf)[0] + 1))
+  call WaitForAssert({-> assert_match('^!\s*$', term_getline(buf, term_getcursor(buf)[0] + 1))})
   " cursor line also shows !
   call assert_match('^!\s*$', term_getline(buf, term_getcursor(buf)[0]))
   bwipe!
diff --git a/src/testdir/test_quotestar.vim b/src/testdir/test_quotestar.vim
index b83fbe40e..ce5a9ee82 100644
--- a/src/testdir/test_quotestar.vim
+++ b/src/testdir/test_quotestar.vim
@@ -54,34 +54,33 @@ func Do_test_quotestar_for_x11()
   " Make sure a previous server has exited
   try
     call remote_send(name, ":qa!\<CR>")
-    call WaitFor('serverlist() !~ "' . name . '"')
   catch /E241:/
   endtry
-  call assert_notmatch(name, serverlist())
+  call WaitForAssert({-> assert_notmatch(name, serverlist())})
 
   let cmd .= ' --servername ' . name
   let job = job_start(cmd, {'stoponexit': 'kill', 'out_io': 'null'})
-  call WaitFor({-> job_status(job) == "run"})
+  call WaitForAssert({-> assert_equal("run", job_status(job))})
 
   " Takes a short while for the server to be active.
-  call WaitFor('serverlist() =~ "' . name . '"')
+  call WaitForAssert({-> assert_match(name, serverlist())})
 
   " Wait for the server to be up and answering requests.  One second is not
   " always sufficient.
-  call WaitFor('remote_expr("' . name . '", "v:version", "", 2) != ""')
+  call WaitForAssert({-> assert_notequal('', remote_expr(name, "v:version", "", 2))})
 
   " Clear the *-register of this vim instance and wait for it to be picked up
   " by the server.
   let @* = 'no'
   call remote_foreground(name)
-  call WaitFor('remote_expr("' . name . '", "@*", "", 1) == "no"')
+  call WaitForAssert({-> assert_equal("no", remote_expr(name, "@*", "", 1))})
 
   " Set the * register on the server.
   call remote_send(name, ":let @* = 'yes'\<CR>")
-  call WaitFor('remote_expr("' . name . '", "@*", "", 1) == "yes"')
+  call WaitForAssert({-> assert_equal("yes", remote_expr(name, "@*", "", 1))})
 
   " Check that the *-register of this vim instance is changed as expected.
-  call WaitFor('@* == "yes"')
+  call WaitForAssert({-> assert_equal("yes", @*)})
 
   " Handle the large selection over 262040 byte.
   let length = 262044
@@ -109,18 +108,17 @@ func Do_test_quotestar_for_x11()
       call remote_send(name, ":gui -f\<CR>")
     endif
     " Wait for the server in the GUI to be up and answering requests.
-    call WaitFor('remote_expr("' . name . '", "has(\"gui_running\")", "", 1) =~ "1"')
+    call WaitForAssert({-> assert_match("1", remote_expr(name, "has('gui_running')", "", 1))})
 
     call remote_send(name, ":let @* = 'maybe'\<CR>")
-    call WaitFor('remote_expr("' . name . '", "@*", "", 1) == "maybe"')
-    call assert_equal('maybe', remote_expr(name, "@*", "", 2))
+    call WaitForAssert({-> assert_equal("maybe", remote_expr(name, "@*", "", 2))})
 
     call assert_equal('maybe', @*)
   endif
 
   call remote_send(name, ":qa!\<CR>")
   try
-    call WaitFor({-> job_status(job) == "dead"})
+    call WaitForAssert({-> assert_equal("dead", job_status(job))})
   finally
     if job_status(job) != 'dead'
       call assert_report('Server did not exit')
diff --git a/src/testdir/test_search.vim b/src/testdir/test_search.vim
index 93a03434c..c923e9d40 100644
--- a/src/testdir/test_search.vim
+++ b/src/testdir/test_search.vim
@@ -494,7 +494,7 @@ func Test_search_cmdline8()
   call writefile(lines, 'Xsearch.txt')
   let buf = term_start([GetVimProg(), '--clean', '-c', 'set noswapfile', 'Xsearch.txt'], {'term_rows': 3})
 
-  call WaitFor({-> lines == [term_getline(buf, 1), term_getline(buf, 2)] })
+  call WaitForAssert({-> assert_equal(lines, [term_getline(buf, 1), term_getline(buf, 2)])})
 
   call term_sendkeys(buf, ":set incsearch hlsearch\<cr>")
   call term_sendkeys(buf, ":14vsp\<cr>")
@@ -619,7 +619,7 @@ func Test_search_cmdline_incsearch_highlight_attr()
   call writefile(lines, 'Xsearch.txt')
   let buf = term_start([GetVimProg(), '--clean', '-c', 'set noswapfile', 'Xsearch.txt'], {'term_rows': 3})
 
-  call WaitFor({-> lines == [term_getline(buf, 1), term_getline(buf, 2)] })
+  call WaitForAssert({-> assert_equal(lines, [term_getline(buf, 1), term_getline(buf, 2)])})
   " wait for vim to complete initialization
   call term_wait(buf)
 
diff --git a/src/testdir/test_terminal.vim b/src/testdir/test_terminal.vim
index 07386a318..c9d463715 100644
--- a/src/testdir/test_terminal.vim
+++ b/src/testdir/test_terminal.vim
@@ -100,7 +100,6 @@ func Test_terminal_split_quit()
 
   quit!
   call WaitForAssert({-> assert_equal('dead', job_status(g:job))})
-  call assert_equal('dead', job_status(g:job))
 
   exe buf . 'bwipe'
   unlet g:job
@@ -142,8 +141,8 @@ func Test_terminal_nasty_cb()
   let g:buf = term_start(cmd, {'exit_cb': function('s:Nasty_exit_cb')})
   let g:job = term_getjob(g:buf)
 
-  call WaitFor('job_status(g:job) == "dead"')
-  call WaitFor('g:buf == 0')
+  call WaitForAssert({-> assert_equal("dead", job_status(g:job))})
+  call WaitForAssert({-> assert_equal(0, g:buf)})
   unlet g:buf
   unlet g:job
   call delete('Xtext')
@@ -190,12 +189,12 @@ func Test_terminal_scrape_123()
   call term_wait(buf)
   " On MS-Windows we first get a startup message of two lines, wait for the
   " "cls" to happen, after that we have one line with three characters.
-  call WaitFor({-> len(term_scrape(buf, 1)) == 3})
+  call WaitForAssert({-> assert_equal(3, len(term_scrape(buf, 1)))})
   call Check_123(buf)
 
   " Must still work after the job ended.
   let job = term_getjob(buf)
-  call WaitFor({-> job_status(job) == "dead"})
+  call WaitForAssert({-> assert_equal("dead", job_status(job))})
   call term_wait(buf)
   call Check_123(buf)
 
@@ -234,7 +233,7 @@ func Test_terminal_scrape_multibyte()
   call assert_equal('s', l[6].chars)
 
   let job = term_getjob(buf)
-  call WaitFor({-> job_status(job) == "dead"})
+  call WaitForAssert({-> assert_equal("dead", job_status(job))})
   call term_wait(buf)
 
   exe buf . 'bwipe'
@@ -251,7 +250,7 @@ func Test_terminal_scroll()
   let buf = term_start(cmd)
 
   let job = term_getjob(buf)
-  call WaitFor({-> job_status(job) == "dead"})
+  call WaitForAssert({-> assert_equal("dead", job_status(job))})
   call term_wait(buf)
   if has('win32')
     " TODO: this should not be needed
@@ -281,7 +280,7 @@ func Test_terminal_scrollback()
   endif
   let rows = term_getsize(buf)[0]
   " On MS-Windows there is an empty line, check both last line and above it.
-  call WaitFor({-> term_getline(buf, rows - 1) . term_getline(buf, rows - 2) =~ '149'})
+  call WaitForAssert({-> assert_match( '149', term_getline(buf, rows - 1) . term_getline(buf, rows - 2))})
   let lines = line('$')
   call assert_inrange(91, 100, lines)
 
@@ -408,16 +407,16 @@ func Test_terminal_finish_open_close()
   let buf = bufnr('%')
   call assert_equal(2, winnr('$'))
   " Wait for the shell to display a prompt
-  call WaitFor({-> term_getline(buf, 1) != ""})
+  call WaitForAssert({-> assert_notequal('', term_getline(buf, 1))})
   call Stop_shell_in_terminal(buf)
-  call WaitFor("winnr('$') == 1", waittime)
+  call WaitForAssert({-> assert_equal(1, winnr('$'))}, waittime)
 
   " shell terminal that does not close automatically
   terminal ++noclose
   let buf = bufnr('%')
   call assert_equal(2, winnr('$'))
   " Wait for the shell to display a prompt
-  call WaitFor({-> term_getline(buf, 1) != ""})
+  call WaitForAssert({-> assert_notequal('', term_getline(buf, 1))})
   call Stop_shell_in_terminal(buf)
   call assert_equal(2, winnr('$'))
   quit
@@ -426,36 +425,32 @@ func Test_terminal_finish_open_close()
   exe 'terminal ++close ' . cmd
   call assert_equal(2, winnr('$'))
   wincmd p
-  call WaitFor("winnr('$') == 1", waittime)
+  call WaitForAssert({-> assert_equal(1, winnr('$'))}, waittime)
 
   call term_start(cmd, {'term_finish': 'close'})
   call assert_equal(2, winnr('$'))
   wincmd p
-  call WaitFor("winnr('$') == 1", waittime)
+  call WaitForAssert({-> assert_equal(1, winnr('$'))}, waittime)
   call assert_equal(1, winnr('$'))
 
   exe 'terminal ++open ' . cmd
   close!
-  call WaitFor("winnr('$') == 2", waittime)
-  call assert_equal(2, winnr('$'))
+  call WaitForAssert({-> assert_equal(2, winnr('$'))}, waittime)
   bwipe
 
   call term_start(cmd, {'term_finish': 'open'})
   close!
-  call WaitFor("winnr('$') == 2", waittime)
-  call assert_equal(2, winnr('$'))
+  call WaitForAssert({-> assert_equal(2, winnr('$'))}, waittime)
   bwipe
 
   exe 'terminal ++hidden ++open ' . cmd
   call assert_equal(1, winnr('$'))
-  call WaitFor("winnr('$') == 2", waittime)
-  call assert_equal(2, winnr('$'))
+  call WaitForAssert({-> assert_equal(2, winnr('$'))}, waittime)
   bwipe
 
   call term_start(cmd, {'term_finish': 'open', 'hidden': 1})
   call assert_equal(1, winnr('$'))
-  call WaitFor("winnr('$') == 2", waittime)
-  call assert_equal(2, winnr('$'))
+  call WaitForAssert({-> assert_equal(2, winnr('$'))}, waittime)
   bwipe
 
   call assert_fails("call term_start(cmd, {'term_opencmd': 'open'})", 'E475:')
@@ -465,8 +460,7 @@ func Test_terminal_finish_open_close()
 
   call term_start(cmd, {'term_finish': 'open', 'term_opencmd': '4split | buffer %d'})
   close!
-  call WaitFor("winnr('$') == 2", waittime)
-  call assert_equal(2, winnr('$'))
+  call WaitForAssert({-> assert_equal(2, winnr('$'))}, waittime)
   call assert_equal(4, winheight(0))
   bwipe
 endfunc
@@ -477,8 +471,7 @@ func Test_terminal_cwd()
   endif
   call mkdir('Xdir')
   let buf = term_start('pwd', {'cwd': 'Xdir'})
-  call WaitFor('"Xdir" == fnamemodify(getline(1), ":t")')
-  call assert_equal('Xdir', fnamemodify(getline(1), ":t"))
+  call WaitForAssert({-> assert_equal('Xdir', fnamemodify(getline(1), ":t"))})
 
   exe buf . 'bwipe'
   call delete('Xdir', 'rf')
@@ -490,7 +483,7 @@ func Test_terminal_servername()
   endif
   let buf = Run_shell_in_terminal({})
   " Wait for the shell to display a prompt
-  call WaitFor({-> term_getline(buf, 1) != ""})
+  call WaitForAssert({-> assert_notequal('', term_getline(buf, 1))})
   if has('win32')
     call term_sendkeys(buf, "echo %VIM_SERVERNAME%\r")
   else
@@ -508,7 +501,7 @@ endfunc
 func Test_terminal_env()
   let buf = Run_shell_in_terminal({'env': {'TESTENV': 'correct'}})
   " Wait for the shell to display a prompt
-  call WaitFor({-> term_getline(buf, 1) != ""})
+  call WaitForAssert({-> assert_notequal('', term_getline(buf, 1))})
   if has('win32')
     call term_sendkeys(buf, "echo %TESTENV%\r")
   else
@@ -516,8 +509,7 @@ func Test_terminal_env()
   endif
   call term_wait(buf)
   call Stop_shell_in_terminal(buf)
-  call WaitFor('getline(2) == "correct"')
-  call assert_equal('correct', getline(2))
+  call WaitForAssert({-> assert_equal('correct', getline(2))})
 
   exe buf . 'bwipe'
 endfunc
@@ -539,8 +531,7 @@ func Test_zz_terminal_in_gui()
   call term_wait(buf)
 
   " closing window wipes out the terminal buffer a with finished job
-  call WaitFor("winnr('$') == 1")
-  call assert_equal(1, winnr('$'))
+  call WaitForAssert({-> assert_equal(1, winnr('$'))})
   call assert_equal("", bufname(buf))
 
   unlet g:job
@@ -592,7 +583,7 @@ func Test_terminal_write_stdin()
   new
   call setline(1, ['one', 'two', 'three'])
   %term wc
-  call WaitFor('getline("$") =~ "3"')
+  call WaitForAssert({-> assert_match('3', getline("$"))})
   let nrs = split(getline('$'))
   call assert_equal(['3', '3', '14'], nrs)
   bwipe
@@ -600,7 +591,7 @@ func Test_terminal_write_stdin()
   new
   call setline(1, ['one', 'two', 'three', 'four'])
   2,3term wc
-  call WaitFor('getline("$") =~ "2"')
+  call WaitForAssert({-> assert_match('2', getline("$"))})
   let nrs = split(getline('$'))
   call assert_equal(['2', '2', '10'], nrs)
   bwipe
@@ -622,7 +613,7 @@ func Test_terminal_write_stdin()
       new
       call setline(1, ['print("hello")'])
       1term ++eof=<C-Z> python
-      call WaitFor('getline("$") =~ "Z"')
+      call WaitForAssert({-> assert_match('Z', getline("$"))})
       call assert_equal('hello', getline(line('$') - 1))
       bwipe
     endif
@@ -646,9 +637,8 @@ func Test_terminal_no_cmd()
   else
     call system('echo "look here" > ' . pty)
   endif
-  call WaitFor({-> term_getline(buf, 1) =~ "look here"})
+  call WaitForAssert({-> assert_match('look here', term_getline(buf, 1))})
 
-  call assert_match('look here', term_getline(buf, 1))
   bwipe!
 endfunc
 
@@ -660,8 +650,7 @@ func Test_terminal_special_chars()
   call mkdir('Xdir with spaces')
   call writefile(['x'], 'Xdir with spaces/quoted"file')
   term ls Xdir\ with\ spaces/quoted\"file
-  call WaitFor('term_getline("", 1) =~ "quoted"')
-  call assert_match('quoted"file', term_getline('', 1))
+  call WaitForAssert({-> assert_match('quoted"file', term_getline('', 1))})
   call term_wait('')
 
   call delete('Xdir with spaces', 'rf')
@@ -691,10 +680,10 @@ func Test_terminal_redir_file()
     let cmd = Get_cat_123_cmd()
     let buf = term_start(cmd, {'out_io': 'file', 'out_name': 'Xfile'})
     call term_wait(buf)
-    call WaitFor('len(readfile("Xfile")) > 0')
+    call WaitForAssert({-> assert_notequal(0, len(readfile("Xfile")))})
     call assert_match('123', readfile('Xfile')[0])
     let g:job = term_getjob(buf)
-    call WaitFor('job_status(g:job) == "dead"')
+    call WaitForAssert({-> assert_equal("dead", job_status(g:job))})
     call delete('Xfile')
     bwipe
   endif
@@ -703,10 +692,9 @@ func Test_terminal_redir_file()
     call writefile(['one line'], 'Xfile')
     let buf = term_start('cat', {'in_io': 'file', 'in_name': 'Xfile'})
     call term_wait(buf)
-    call WaitFor('term_getline(' . buf . ', 1) == "one line"')
-    call assert_equal('one line', term_getline(buf, 1))
+    call WaitForAssert({-> assert_equal('one line', term_getline(buf, 1))})
     let g:job = term_getjob(buf)
-    call WaitFor('job_status(g:job) == "dead"')
+    call WaitForAssert({-> assert_equal('dead', job_status(g:job))})
     bwipe
     call delete('Xfile')
   endif
@@ -726,7 +714,7 @@ func TerminalTmap(remap)
   call assert_equal('456', maparg('123', 't'))
   call assert_equal('abxde', maparg('456', 't'))
   call feedkeys("123", 'tx')
-  call WaitFor({-> term_getline(buf, term_getcursor(buf)[0]) =~ 'abxde\|456'})
+  call WaitForAssert({-> assert_match('abxde\|456', term_getline(buf, term_getcursor(buf)[0]))})
   let lnum = term_getcursor(buf)[0]
   if a:remap
     call assert_match('abxde', term_getline(buf, lnum))
@@ -825,8 +813,7 @@ func Test_terminal_composing_unicode()
   call assert_equal("\u00a0\u0308", l[3].chars)
 
   call term_sendkeys(buf, "exit\r")
-  call WaitFor('job_status(g:job) == "dead"')
-  call assert_equal('dead', job_status(g:job))
+  call WaitForAssert({-> assert_equal('dead', job_status(g:job))})
   bwipe!
   unlet g:job
   let &encoding = save_enc
@@ -849,7 +836,7 @@ func Test_terminal_aucmd_on_close()
   call setline(1, ['one', 'two'])
   exe 'term ++close ' . cmd
   wincmd p
-  call WaitFor("winnr('$') == 2", waittime)
+  call WaitForAssert({-> assert_equal(2, winnr('$'))}, waittime)
   call assert_equal(1, s:called)
   bwipe!
 
@@ -875,16 +862,16 @@ func Test_terminal_response_to_control_sequence()
   endif
 
   let buf = Run_shell_in_terminal({})
-  call WaitFor({-> term_getline(buf, 1) != ''})
+  call WaitForAssert({-> assert_notequal('', term_getline(buf, 1))})
 
   call term_sendkeys(buf, "cat\<CR>")
-  call WaitFor({-> term_getline(buf, 1) =~ 'cat'})
+  call WaitForAssert({-> assert_match('cat', term_getline(buf, 1))})
 
   " Request the cursor position.
   call term_sendkeys(buf, "\x1b[6n\<CR>")
 
   " Wait for output from tty to display, below an empty line.
-  call WaitFor({-> term_getline(buf, 4) =~ '3;1R'})
+  call WaitForAssert({-> assert_match('3;1R', term_getline(buf, 4))})
 
   " End "cat" gently.
   call term_sendkeys(buf, "\<CR>\<C-D>")
@@ -961,14 +948,14 @@ func Test_terminal_qall_prompt()
 
   " Open a terminal window and wait for the prompt to appear
   call term_sendkeys(buf, ":term\<CR>")
-  call WaitFor({-> term_getline(buf, 10) =~ '\[running]'})
-  call WaitFor({-> term_getline(buf, 1) !~ '^\s*$'})
+  call WaitForAssert({-> assert_match('\[running]', term_getline(buf, 10))})
+  call WaitForAssert({-> assert_notmatch('^\s*$', term_getline(buf, 1))})
 
   " make Vim exit, it will prompt to kill the shell
   call term_sendkeys(buf, "\<C-W>:confirm qall\<CR>")
-  call WaitFor({-> term_getline(buf, 20) =~ 'ancel:'})
+  call WaitForAssert({-> assert_match('ancel:', term_getline(buf, 20))})
   call term_sendkeys(buf, "y")
-  call WaitFor({-> term_getstatus(buf) == "finished"})
+  call WaitForAssert({-> assert_equal('finished', term_getstatus(buf))})
 
   " close the terminal window where Vim was running
   quit
@@ -1025,7 +1012,7 @@ func Test_terminal_dumpwrite_composing()
   let text = " a\u0300 e\u0302 o\u0308"
   call writefile([text], 'Xcomposing')
   let buf = RunVimInTerminal('Xcomposing', {})
-  call WaitFor({-> term_getline(buf, 1) =~ text})
+  call WaitForAssert({-> assert_match(text, term_getline(buf, 1))})
   call term_dumpwrite(buf, 'Xdump')
   let dumpline = readfile('Xdump')[0]
   call assert_match('|à| |ê| |ö', dumpline)
@@ -1235,7 +1222,7 @@ func Test_terminal_api_drop_oldwin()
 	\ "set t_ts=",
 	\ ], 'Xscript')
   let buf = RunVimInTerminal('-S Xscript', {'rows': 10})
-  call WaitFor({-> expand('%:t') =='Xtextfile'})
+  call WaitForAssert({-> assert_equal('Xtextfile', expand('%:t'))})
   call assert_equal(textfile_winid, win_getid())
 
   call StopVimInTerminal(buf)
@@ -1284,7 +1271,7 @@ func Test_terminal_api_call_fails()
   call WriteApiCall('TryThis')
   call ch_logfile('Xlog', 'w')
   let buf = RunVimInTerminal('-S Xscript', {})
-  call WaitFor({-> string(readfile('Xlog')) =~ 'Invalid function name: TryThis'})
+  call WaitForAssert({-> assert_match('Invalid function name: TryThis', string(readfile('Xlog')))})
 
   call StopVimInTerminal(buf)
   call delete('Xscript')
@@ -1309,7 +1296,7 @@ func Test_terminal_api_call_fail_delete()
 
   call WriteApiCall('Tapi_Delete')
   let buf = RunVimInTerminal('-S Xscript', {})
-  call WaitFor({-> s:caught_e937 == 1})
+  call WaitForAssert({-> assert_equal(1, s:caught_e937)})
 
   call StopVimInTerminal(buf)
   call delete('Xscript')
diff --git a/src/testdir/test_timers.vim b/src/testdir/test_timers.vim
index df42b2c2b..79a5ba58c 100644
--- a/src/testdir/test_timers.vim
+++ b/src/testdir/test_timers.vim
@@ -143,7 +143,7 @@ endfunc
 func Test_delete_myself()
   let g:called = 0
   let t = timer_start(10, 'StopMyself', {'repeat': -1})
-  call WaitFor('g:called == 2')
+  call WaitForAssert({-> assert_equal(2, g:called)})
   call assert_equal(2, g:called)
   call assert_equal([], timer_info(t))
 endfunc
@@ -206,7 +206,7 @@ func Test_timer_errors()
   let g:call_count = 0
   let timer = timer_start(10, 'FuncWithError', {'repeat': -1})
   " Timer will be stopped after failing 3 out of 3 times.
-  call WaitFor('g:call_count == 3')
+  call WaitForAssert({-> assert_equal(3, g:call_count)})
   sleep 50m
   call assert_equal(3, g:call_count)
 endfunc
@@ -224,7 +224,7 @@ func Test_timer_catch_error()
   let g:call_count = 0
   let timer = timer_start(10, 'FuncWithCaughtError', {'repeat': 4})
   " Timer will not be stopped.
-  call WaitFor('g:call_count == 4')
+  call WaitForAssert({-> assert_equal(4, g:call_count)})
   sleep 50m
   call assert_equal(4, g:call_count)
 endfunc