runtime(syntax-tests): simplify code and allow filetype options

The whole testdir/runtest.vim is a bit of a mess. So this is an attempt
to improving the current state. First of all, let's move most of the
code into a single RunTest() function so that it's easier to run this
manually.

Then, let's add the possibility to customize filetype specific tests by
applying filetype specific options. We will make use of it in the next
commit, where the provided java file uses tabs, which cause line
wrapping which will then cause the scrolling to miss some lines when
redrawing (see #14105)

related: #14105

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/syntax/testdir/runtest.vim b/runtime/syntax/testdir/runtest.vim
index d2ce3d1..a2cdef3 100644
--- a/runtime/syntax/testdir/runtest.vim
+++ b/runtime/syntax/testdir/runtest.vim
@@ -85,164 +85,180 @@
   endif
 endfunc
 
-let ok_count = 0
-let failed_tests = []
-let skipped_count = 0
-let MAX_FAILED_COUNT = 5
-for fname in glob('input/*.*', 1, 1)
-  if fname =~ '\~$'
-    " backup file, skip
-    continue
-  endif
-
-  let linecount = readfile(fname)->len()
-  let root = fnamemodify(fname, ':t:r')
-  let filetype = substitute(root, '\([^_.]*\)[_.].*', '\1', '')
-  let failed_root = 'failed/' .. root
-
-  " Execute the test if the "done" file does not exist or when the input file
-  " is newer.
-  let in_time = getftime(fname)
-  let out_time = getftime('done/' .. root)
-  if out_time < 0 || in_time > out_time
-    call ch_log('running tests for: ' .. fname)
-
-    for dumpname in glob(failed_root .. '_\d*\.dump', 1, 1)
-      call delete(dumpname)
-    endfor
-    call delete('done/' .. root)
-
-    let lines =<< trim END
-      syntax on
-
-      " extra info for shell variables
-      func ShellInfo()
-	let msg = ''
-	for [key, val] in items(b:)
-	  if key =~ '^is_'
-	    let msg ..= key .. ': ' .. val .. ', '
-	  endif
-	endfor
-	if msg != ''
-	  echomsg msg
-	endif
-      endfunc
-
-      au! SwapExists * call HandleSwapExists()
-      func HandleSwapExists()
-	" Ignore finding a swap file for the test input, the user might be
-	" editing it and that's OK.
-	if expand('<afile>') =~ 'input[/\\].*\..*'
-	  let v:swapchoice = 'e'
-	endif
-      endfunc
-    END
-    call writefile(lines, 'Xtestscript')
-
-    " close all but the last window
-    while winnr('$') > 1
-      close
-    endwhile
-
-    " Redraw to make sure that messages are cleared and there is enough space
-    " for the terminal window.
-    redraw
-
-    let buf = RunVimInTerminal('-S Xtestscript', {})
-    " edit the file only after catching the SwapExists event
-    call term_sendkeys(buf, ":edit " .. fname .. "\<CR>")
-
-    if filetype == 'sh'
-      call term_sendkeys(buf, ":call ShellInfo()\<CR>")
+func RunTest()
+  let ok_count = 0
+  let failed_tests = []
+  let skipped_count = 0
+  let MAX_FAILED_COUNT = 5
+  for fname in glob('input/*.*', 1, 1)
+    if fname =~ '\~$'
+      " backup file, skip
+      continue
     endif
 
-    " Screendump at the start of the file: failed/root_00.dump
-    let root_00 = root .. '_00'
-    call ch_log('First screendump for ' .. fname .. ': failed/' .. root_00 .. '.dump')
-    let fail = VerifyScreenDump(buf, root_00, {})
+    let linecount = readfile(fname)->len()
+    let root = fnamemodify(fname, ':t:r')
+    let filetype = substitute(root, '\([^_.]*\)[_.].*', '\1', '')
+    let failed_root = 'failed/' .. root
 
-    " clear the shell info if there are not enough lines to cause a scroll
-    if filetype == 'sh' && linecount <= 19
-      call term_sendkeys(buf, ":redraw\<CR>")
-    endif
+    " Execute the test if the "done" file does not exist or when the input file
+    " is newer.
+    let in_time = getftime(fname)
+    let out_time = getftime('done/' .. root)
+    if out_time < 0 || in_time > out_time
+      call ch_log('running tests for: ' .. fname)
 
-    " Make a Screendump every 18 lines of the file: failed/root_NN.dump
-    let topline = 1
-    let nr = 1
-    while linecount - topline > 20
-      let topline += 18
-      call term_sendkeys(buf, printf("%dGzt", topline))
-      let root_next = root .. printf('_%02d', nr)
-      call ch_log('Next screendump for ' .. fname .. ': failed/' .. root_next .. '.dump')
-      let fail += VerifyScreenDump(buf, root_next, {})
-      let nr += 1
-    endwhile
-
-    " Screendump at the end of the file: failed/root_99.dump
-    call term_sendkeys(buf, 'Gzb')
-    let root_last = root .. '_99'
-    call ch_log('Last screendump for ' .. fname .. ': failed/' .. root_last .. '.dump')
-    let fail += VerifyScreenDump(buf, root_last, {})
-
-    call StopVimInTerminal(buf)
-    call delete('Xtestscript')
-
-    " redraw here to avoid the following messages to get mixed up with screen
-    " output.
-    redraw
-
-    " Add any assert errors to s:messages.
-    if len(v:errors) > 0
-      call extend(s:messages, v:errors)
-      " Echo the errors here, in case the script aborts or the "messages" file
-      " is not displayed later.
-      echomsg v:errors
-      let v:errors = []
-      let fail += 1
-    endif
-
-    if fail == 0
-      call Message("Test " .. root .. " OK")
-
-      call writefile(['OK'], 'done/' .. root)
-
-      let ok_count += 1
-    else
-      call Message("Test " .. root .. " FAILED")
-
+      for dumpname in glob(failed_root .. '_\d*\.dump', 1, 1)
+	call delete(dumpname)
+      endfor
       call delete('done/' .. root)
 
-      eval failed_tests->add(root)
-      if len(failed_tests) > MAX_FAILED_COUNT
-	call Message('')
-	call Message('Too many errors, aborting')
+      let lines =<< trim END
+	syntax on
+
+	" extra info for shell variables
+	func ShellInfo()
+	  let msg = ''
+	  for [key, val] in items(b:)
+	    if key =~ '^is_'
+	      let msg ..= key .. ': ' .. val .. ', '
+	    endif
+	  endfor
+	  if msg != ''
+	    echomsg msg
+	  endif
+	endfunc
+
+	au! SwapExists * call HandleSwapExists()
+	func HandleSwapExists()
+	  " Ignore finding a swap file for the test input, the user might be
+	  " editing it and that's OK.
+	  if expand('<afile>') =~ 'input[/\\].*\..*'
+	    let v:swapchoice = 'e'
+	  endif
+	endfunc
+
+	func LoadFiletype(type)
+	  for file in glob("ftplugin/" .. a:type .. "*.vim", 1, 1)
+	    exe "source " .. file
+	  endfor
+	  redraw!
+	endfunc
+
+      END
+      call writefile(lines, 'Xtestscript')
+
+      " close all but the last window
+      while winnr('$') > 1
+	close
+      endwhile
+
+      " Redraw to make sure that messages are cleared and there is enough space
+      " for the terminal window.
+      redraw
+
+      let buf = RunVimInTerminal('-S Xtestscript', {})
+      " edit the file only after catching the SwapExists event
+      call term_sendkeys(buf, ":edit " .. fname .. "\<CR>")
+      " load filetype specific settings
+      call term_sendkeys(buf, ":call LoadFiletype('" .. filetype .. "')\<CR>")
+
+      if filetype == 'sh'
+	call term_sendkeys(buf, ":call ShellInfo()\<CR>")
       endif
+
+      " Screendump at the start of the file: failed/root_00.dump
+      let root_00 = root .. '_00'
+      call ch_log('First screendump for ' .. fname .. ': failed/' .. root_00 .. '.dump')
+      let fail = VerifyScreenDump(buf, root_00, {})
+
+      " clear the shell info if there are not enough lines to cause a scroll
+      if filetype == 'sh' && linecount <= 19
+	call term_sendkeys(buf, ":redraw\<CR>")
+      endif
+
+      " Make a Screendump every 18 lines of the file: failed/root_NN.dump
+      let topline = 1
+      let nr = 1
+      while linecount - topline > 20
+	let topline += 18
+	call term_sendkeys(buf, printf("%dGzt", topline))
+	let root_next = root .. printf('_%02d', nr)
+	call ch_log('Next screendump for ' .. fname .. ': failed/' .. root_next .. '.dump')
+	let fail += VerifyScreenDump(buf, root_next, {})
+	let nr += 1
+      endwhile
+
+      " Screendump at the end of the file: failed/root_99.dump
+      call term_sendkeys(buf, 'Gzb')
+      let root_last = root .. '_99'
+      call ch_log('Last screendump for ' .. fname .. ': failed/' .. root_last .. '.dump')
+      let fail += VerifyScreenDump(buf, root_last, {})
+
+      call StopVimInTerminal(buf)
+      call delete('Xtestscript')
+
+      " redraw here to avoid the following messages to get mixed up with screen
+      " output.
+      redraw
+
+      " Add any assert errors to s:messages.
+      if len(v:errors) > 0
+	call extend(s:messages, v:errors)
+	" Echo the errors here, in case the script aborts or the "messages" file
+	" is not displayed later.
+	echomsg v:errors
+	let v:errors = []
+	let fail += 1
+      endif
+
+      if fail == 0
+	call Message("Test " .. root .. " OK")
+
+	call writefile(['OK'], 'done/' .. root)
+
+	let ok_count += 1
+      else
+	call Message("Test " .. root .. " FAILED")
+
+	call delete('done/' .. root)
+
+	eval failed_tests->add(root)
+	if len(failed_tests) > MAX_FAILED_COUNT
+	  call Message('')
+	  call Message('Too many errors, aborting')
+	endif
+      endif
+    else
+      call Message("Test " .. root .. " skipped")
+      let skipped_count += 1
     endif
-  else
-    call Message("Test " .. root .. " skipped")
-    let skipped_count += 1
+
+    " Append messages to the file "testdir/messages"
+    call AppendMessages('Input file ' .. fname .. ':')
+
+    if len(failed_tests) > MAX_FAILED_COUNT
+      break
+    endif
+  endfor
+
+  call Message(s:test_run_message)
+  call Message('OK: ' .. ok_count)
+  call Message('FAILED: ' .. len(failed_tests) .. ': ' .. string(failed_tests))
+  call Message('skipped: ' .. skipped_count)
+  call AppendMessages('== SUMMARY ==')
+
+  if len(failed_tests) > 0
+    " have make report an error
+    cquit
   endif
+endfunc
 
-  " Append messages to the file "testdir/messages"
-  call AppendMessages('Input file ' .. fname .. ':')
-
-  if len(failed_tests) > MAX_FAILED_COUNT
-    break
-  endif
-endfor
-
-call Message(s:test_run_message)
-call Message('OK: ' .. ok_count)
-call Message('FAILED: ' .. len(failed_tests) .. ': ' .. string(failed_tests))
-call Message('skipped: ' .. skipped_count)
-call AppendMessages('== SUMMARY ==')
-
-if len(failed_tests) > 0
-  " have make report an error
-  cquit
-endif
+call RunTest()
 
 " Matching "if 1" at the start.
 endif
 
 qall!
+
+" vim:ts=8