vim-patch:8.2.0015: not all modeline variants are tested

Problem:    Not all modeline variants are tested.
Solution:   Add modeline tests. (Dominique Pelle, closes vim/vim#5369)
e74331db4b

src/nvim/testdir/test_modeline.vim

@@ -5,12 +5,30 @@ func Test_modeline_invalid()
   call writefile(['vi:0', 'nothing'], 'Xmodeline')
   let modeline = &modeline
   set modeline
-  call assert_fails('set Xmodeline', 'E518:')
+  call assert_fails('split Xmodeline', 'E518:')
+
+  " Missing end colon (ignored).
+  call writefile(['// vim: set ts=2'], 'Xmodeline')
+  edit Xmodeline_version
+  call assert_equal(8, &ts)
+  bwipe!
+
+  " Missing colon at beginning (ignored).
+  call writefile(['// vim set ts=2:'], 'Xmodeline')
+  edit Xmodeline_version
+  call assert_equal(8, &ts)
+  bwipe!
+
+  " Missing space after vim (ignored).
+  call writefile(['// vim:ts=2:'], 'Xmodeline')
+  edit Xmodeline_version
+  call assert_equal(8, &ts)
+  bwipe!
 
   let &modeline = modeline
   bwipe!
   call delete('Xmodeline')
- endfunc
+endfunc
 
 func Test_modeline_filetype()
   call writefile(['vim: set ft=c :', 'nothing'], 'Xmodeline_filetype')
@@ -60,8 +78,99 @@ func Test_modeline_keymap()
   set keymap= iminsert=0 imsearch=-1
 endfunc
 
+func Test_modeline_version()
+  let modeline = &modeline
+  set modeline
+
+  " Test with vim:{vers}: (version {vers} or later).
+  call writefile(['// vim' .. v:version .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(2, &ts)
+  bwipe!
+
+  call writefile(['// vim' .. (v:version - 100) .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(2, &ts)
+  bwipe!
+
+  call writefile(['// vim' .. (v:version + 100) .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(8, &ts)
+  bw!
+
+  " Test with vim>{vers}: (version after {vers}).
+  call writefile(['// vim>' .. v:version .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(8, &ts)
+  bwipe!
+
+  call writefile(['// vim>' .. (v:version - 100) .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(2, &ts)
+  bwipe!
+
+  call writefile(['// vim>' .. (v:version + 100) .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(8, &ts)
+  bwipe!
+
+  " Test with vim<{vers}: (version before {vers}).
+  call writefile(['// vim<' .. v:version .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(8, &ts)
+  bwipe!
+
+  call writefile(['// vim<' .. (v:version - 100) .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(8, &ts)
+  bwipe!
+
+  call writefile(['// vim<' .. (v:version + 100) .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(2, &ts)
+  bwipe!
+
+  " Test with vim={vers}: (version {vers} only).
+  call writefile(['// vim=' .. v:version .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(2, &ts)
+  bwipe!
+
+  call writefile(['// vim=' .. (v:version - 100) .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(8, &ts)
+  bwipe!
+
+  call writefile(['// vim=' .. (v:version + 100) .. ': ts=2:'], 'Xmodeline_version')
+  edit Xmodeline_version
+  call assert_equal(8, &ts)
+  bwipe!
+
+  let &modeline = modeline
+  call delete('Xmodeline_version')
+endfunc
+
+func Test_modeline_colon()
+  let modeline = &modeline
+  set modeline
+
+  call writefile(['// vim: set showbreak=\: ts=2: sw=2'], 'Xmodeline_colon')
+  edit Xmodeline_colon
+
+  " backlash colon should become colon.
+  call assert_equal(':', &showbreak)
+
+  " 'ts' should be set.
+  " 'sw' should be ignored because it is after the end colon.
+  call assert_equal(2, &ts)
+  call assert_equal(8, &sw)
+
+  let &modeline = modeline
+  call delete('Xmodeline_colon')
+endfunc
+
 func s:modeline_fails(what, text, error)
-  if !exists('+' . a:what)
+  if !exists('+' .. a:what)
     return
   endif
   let fname = "Xmodeline_fails_" . a:what
@@ -119,7 +228,7 @@ func Test_modeline_fails_always()
   call s:modeline_fails('mkspellmem', 'mkspellmem=Something()', 'E520:')
   call s:modeline_fails('mzschemedll', 'mzschemedll=Something()', 'E520:')
   call s:modeline_fails('mzschemegcdll', 'mzschemegcdll=Something()', 'E520:')
-  call s:modeline_fails('modelineexpr', 'modelineexpr=Something()', 'E520:')
+  call s:modeline_fails('modelineexpr', 'modelineexpr', 'E520:')
   call s:modeline_fails('omnifunc', 'omnifunc=Something()', 'E520:')
   call s:modeline_fails('operatorfunc', 'operatorfunc=Something()', 'E520:')
   call s:modeline_fails('perldll', 'perldll=Something()', 'E520:')