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vim/src/testdir/term_util.vim
Yee Cheng Chin e70587dbdb patch 9.1.1110: Vim tests are slow and flaky
Problem:  Vim tests are slow and flaky at the same time due to reliance
          on timeouts which are unreliable.
Solution: improve Vim test performance and reduce flakiness
          (Yee Cheng Chin)

A lot of Vim tests currently rely on waiting a specific amount of time
before asserting a condition. This is bad because 1) it is slow, as the
timeout is hardcoded, 2) it's unreliable as a resource-starved runner
may overshoot the timeout. Also, there are a lot of builtin sleep
commands in commonly used utilities like VerifyScreenDump and WaitFor()
which leads to a lot of unnecessary idle time.

Fix these issues by doing the following:
1. Make utilities like VerifyScreenDump and WaitFor use the lowest wait
   time possible (1 ms). This essentially turns it into a spin wait. On
   fast machines, these will finish very quickly. For existing tests
   that had an implicit reliance on the old timeouts (e.g.
   VerifyScreenDump had a 50ms wait before), fix the tests to wait that
   specific amount explicitly.
2. Fix tests that sleep or wait for long amounts of time to instead
   explicitly use a callback mechanism to be notified when a child
   terminal job has finished. This allows the test to only take as much
   time as possible instead of having to hard code an unreliable
   timeout.

With these fixes, tests should 1) completely quickly on fast machines,
and 2) on slow machines they will still run to completion albeit slowly.
Note that previoulsy both were not true. The hardcoded timeouts meant
that on fast machines the tests were mostly idling wasting time, whereas
on slow machines, the timeouts often were not generous enough to allow
them to run to completion.

closes: #16615

Signed-off-by: Yee Cheng Chin <ychin.git@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
2025-02-13 20:55:45 +01:00

212 lines
6.4 KiB
VimL

" Functions about terminal shared by several tests
" Only load this script once.
if exists('*CanRunVimInTerminal')
finish
endif
source shared.vim
" For most tests we need to be able to run terminal Vim with 256 colors. On
" MS-Windows the console only has 16 colors and the GUI can't run in a
" terminal.
func CanRunVimInTerminal()
return has('terminal') && !has('win32')
endfunc
" Skip the rest if there is no terminal feature at all.
if !has('terminal')
finish
endif
" Stops the shell running in terminal "buf".
func StopShellInTerminal(buf)
call term_sendkeys(a:buf, "exit\r")
let job = term_getjob(a:buf)
call WaitForAssert({-> assert_equal("dead", job_status(job))})
call TermWait(a:buf)
endfunc
" Wrapper around term_wait() to allow more time for re-runs of flaky tests
" The second argument is the minimum time to wait in msec, 10 if omitted.
func TermWait(buf, ...)
let wait_time = a:0 ? a:1 : 10
if exists('g:run_nr')
if g:run_nr == 2
let wait_time *= 4
elseif g:run_nr > 2
let wait_time *= 10
endif
endif
call term_wait(a:buf, wait_time)
" In case it wasn't set yet.
let g:test_is_flaky = 1
endfunc
" Run Vim with "arguments" in a new terminal window.
" By default uses a size of 20 lines and 75 columns.
" Returns the buffer number of the terminal.
"
" Options is a dictionary, these items are recognized:
" "keep_t_u7" - when 1 do not make t_u7 empty (resetting t_u7 avoids clearing
" parts of line 2 and 3 on the display)
" "rows" - height of the terminal window (max. 20)
" "cols" - width of the terminal window (max. 78)
" "statusoff" - number of lines the status is offset from default
" "wait_for_ruler" - if zero then don't wait for ruler to show
" "no_clean" - if non-zero then remove "--clean" from the command
" "cmd" - run any other command, e.g. "xxd" (used in xxd test)
" "env" - additional environment variables, e.g. $TERM variable
func RunVimInTerminal(arguments, options)
" If Vim doesn't exit a swap file remains, causing other tests to fail.
" Remove it here.
call delete(".swp")
if exists('$COLORFGBG')
" Clear $COLORFGBG to avoid 'background' being set to "dark", which will
" only be corrected if the response to t_RB is received, which may be too
" late.
let $COLORFGBG = ''
endif
" Make a horizontal and vertical split, so that we can get exactly the right
" size terminal window. Works only when the current window is full width.
call assert_equal(&columns, winwidth(0))
split
vsplit
" Always do this with 256 colors and a light background.
set t_Co=256 background=light
hi Normal ctermfg=NONE ctermbg=NONE
" Make the window 20 lines high and 75 columns, unless told otherwise or
" 'termwinsize' is set.
let rows = get(a:options, 'rows', 20)
let cols = get(a:options, 'cols', 75)
let statusoff = get(a:options, 'statusoff', 1)
if get(a:options, 'keep_t_u7', 0)
let reset_u7 = ''
else
let reset_u7 = ' --cmd "set t_u7=" '
endif
if empty(get(a:options, 'cmd', ''))
let cmd = GetVimCommandCleanTerm() .. reset_u7 .. a:arguments
else
let cmd = get(a:options, 'cmd')
endif
if get(a:options, 'no_clean', 0)
let cmd = substitute(cmd, '--clean', '', '')
endif
let options = #{curwin: 1}
if &termwinsize == ''
let options.term_rows = rows
let options.term_cols = cols
endif
" Accept other options whose name starts with 'term_'.
call extend(options, filter(copy(a:options), 'v:key =~# "^term_"'))
" Accept the env dict
if !empty(get(a:options, 'env', {}))
let options.env = get(a:options, 'env')
endif
let buf = term_start(cmd, options)
if &termwinsize == ''
" in the GUI we may end up with a different size, try to set it.
if term_getsize(buf) != [rows, cols]
call term_setsize(buf, rows, cols)
endif
call assert_equal([rows, cols], term_getsize(buf))
else
let rows = term_getsize(buf)[0]
let cols = term_getsize(buf)[1]
endif
call TermWait(buf)
if get(a:options, 'wait_for_ruler', 1) && empty(get(a:options, 'cmd', ''))
" Wait for "All" or "Top" of the ruler to be shown in the last line or in
" the status line of the last window. This can be quite slow (e.g. when
" using valgrind).
" If it fails then show the terminal contents for debugging.
try
call WaitFor({-> len(term_getline(buf, rows)) >= cols - 1 || len(term_getline(buf, rows - statusoff)) >= cols - 1})
catch /timed out after/
let lines = map(range(1, rows), {key, val -> term_getline(buf, val)})
call assert_report('RunVimInTerminal() failed, screen contents: ' . join(lines, "<NL>"))
endtry
endif
" Starting a terminal to run Vim is always considered flaky.
let g:test_is_flaky = 1
return buf
endfunc
" Stop a Vim running in terminal buffer "buf".
func StopVimInTerminal(buf, kill = 1)
" Using a terminal to run Vim is always considered flaky.
let g:test_is_flaky = 1
call assert_equal("running", term_getstatus(a:buf))
" Wait for all the pending updates to terminal to complete
call TermWait(a:buf, 1)
" CTRL-O : works both in Normal mode and Insert mode to start a command line.
" In Command-line it's inserted, the CTRL-U removes it again.
call term_sendkeys(a:buf, "\<C-O>:\<C-U>qa!\<cr>")
" Wait for all the pending updates to terminal to complete
call TermWait(a:buf, 1)
" Wait for the terminal to end.
call WaitForAssert({-> assert_equal("finished", term_getstatus(a:buf))})
" If the buffer still exists forcefully wipe it.
if a:kill && bufexists(a:buf)
exe a:buf .. 'bwipe!'
endif
endfunc
" Open a terminal with a shell, assign the job to g:job and return the buffer
" number.
func Run_shell_in_terminal(options)
if has('win32')
let buf = term_start([&shell, '/D', '/k'], a:options)
else
let buf = term_start(&shell, a:options)
endif
let g:test_is_flaky = 1
let termlist = term_list()
call assert_equal(1, len(termlist))
call assert_equal(buf, termlist[0])
let g:job = term_getjob(buf)
call assert_equal(v:t_job, type(g:job))
let string = string({'job': buf->term_getjob()})
call assert_match("{'job': 'process \\d\\+ run'}", string)
" On slower systems it may take a bit of time before the shell is ready to
" accept keys. This mainly matters when using term_sendkeys() next.
call TermWait(buf)
return buf
endfunc
" Return concatenated lines in terminal.
func Term_getlines(buf, lines)
return join(map(a:lines, 'term_getline(a:buf, v:val)'), '')
endfunc
" vim: shiftwidth=2 sts=2 expandtab