patch 9.0.0719: too many delete() calls in testsv9.0.0719

Problem:    Too many delete() calls in tests.
Solution:   Use deferred delete where possible.

22 files changed, 150 insertions, 282 deletions

diff --git a/src/testdir/test_scriptnames.vim b/src/testdir/test_scriptnames.vim
index b558af5b4d..3f813494cf 100644
--- a/src/testdir/test_scriptnames.vim
+++ b/src/testdir/test_scriptnames.vim
@@ -1,7 +1,7 @@
 
 " Test for the :scriptnames command
 func Test_scriptnames()
-  call writefile(['let did_load_script = 123'], 'Xscripting')
+  call writefile(['let did_load_script = 123'], 'Xscripting', 'D')
   source Xscripting
   call assert_equal(123, g:did_load_script)
 
@@ -22,7 +22,6 @@ func Test_scriptnames()
   call assert_equal('Xscripting', expand('%:t'))
 
   bwipe
-  call delete('Xscripting')
 
   let msgs = execute('messages')
   scriptnames
@@ -47,7 +46,7 @@ func Test_getscriptinfo()
     def Xscript_def_func2()
     enddef
   END
-  call writefile(lines, 'X22script91')
+  call writefile(lines, 'X22script91', 'D')
   source X22script91
   let l = getscriptinfo()
   call assert_match('X22script91$', l[-1].name)
@@ -92,8 +91,6 @@ func Test_getscriptinfo()
   call assert_fails("echo getscriptinfo('foobar')", 'E1206:')
 
   call assert_fails("echo getscriptinfo({'sid': []})", 'E745:')
-
-  call delete('X22script91')
 endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/testdir/test_search.vim b/src/testdir/test_search.vim
index c12c07b33f..3576673591 100644
--- a/src/testdir/test_search.vim
+++ b/src/testdir/test_search.vim
@@ -724,7 +724,7 @@ func Test_search_cmdline8()
   endif
   " Prepare buffer text
   let lines = ['abb vim vim vi', 'vimvivim']
-  call writefile(lines, 'Xsearch.txt')
+  call writefile(lines, 'Xsearch.txt', 'D')
   let buf = term_start([GetVimProg(), '--clean', '-c', 'set noswapfile', 'Xsearch.txt'], {'term_rows': 3})
 
   call WaitForAssert({-> assert_equal(lines, [term_getline(buf, 1), term_getline(buf, 2)])})
@@ -743,9 +743,8 @@ func Test_search_cmdline8()
   call assert_notequal(a1, a2)
   call assert_equal(a0, a2)
   call assert_equal(a1, a3)
-  " clean up
-  call delete('Xsearch.txt')
 
+  " clean up
   bwipe!
 endfunc
 
@@ -859,7 +858,7 @@ func Test_search_cmdline_incsearch_highlight_attr()
 
   " Prepare buffer text
   let lines = ['abb vim vim vi', 'vimvivim']
-  call writefile(lines, 'Xsearch.txt')
+  call writefile(lines, 'Xsearch.txt', 'D')
   let buf = term_start([GetVimProg(), '--clean', '-c', 'set noswapfile', 'Xsearch.txt'], {'term_rows': 3})
 
   call WaitForAssert({-> assert_equal(lines, [term_getline(buf, 1), term_getline(buf, 2)])})
@@ -928,9 +927,7 @@ func Test_search_cmdline_incsearch_highlight_attr()
   let attr_line2 = [a0,a0,a0,a0,a0,a0,a0,a0]
   call assert_equal(attr_line1, map(term_scrape(buf, 1)[:len(attr_line1)-1], 'v:val.attr'))
   call assert_equal(attr_line2, map(term_scrape(buf, 2)[:len(attr_line2)-1], 'v:val.attr'))
-  call delete('Xsearch.txt')
 
-  call delete('Xsearch.txt')
   bwipe!
 endfunc
 
@@ -956,7 +953,7 @@ func Test_incsearch_scrolling()
 	\ 'call setline(1, [dots, dots, dots, "", "target", dots, dots])',
 	\ 'normal gg',
 	\ 'redraw',
-	\ ], 'Xscript')
+	\ ], 'Xscript', 'D')
   let buf = RunVimInTerminal('-S Xscript', {'rows': 9, 'cols': 70})
   " Need to send one key at a time to force a redraw
   call term_sendkeys(buf, '/')
@@ -972,7 +969,6 @@ func Test_incsearch_scrolling()
 
   call term_sendkeys(buf, "\<Esc>")
   call StopVimInTerminal(buf)
-  call delete('Xscript')
 endfunc
 
 func Test_incsearch_search_dump()
@@ -985,7 +981,7 @@ func Test_incsearch_search_dump()
 	\ '  call setline(n, "foo " . n)',
 	\ 'endfor',
 	\ '3',
-	\ ], 'Xis_search_script')
+	\ ], 'Xis_search_script', 'D')
   let buf = RunVimInTerminal('-S Xis_search_script', {'rows': 9, 'cols': 70})
   " Give Vim a chance to redraw to get rid of the spaces in line 2 caused by
   " the 'ambiwidth' check.
@@ -1002,7 +998,6 @@ func Test_incsearch_search_dump()
   call term_sendkeys(buf, "\<Esc>")
 
   call StopVimInTerminal(buf)
-  call delete('Xis_search_script')
 endfunc
 
 func Test_hlsearch_dump()
@@ -1014,7 +1009,7 @@ func Test_hlsearch_dump()
         \ 'call setline(1, ["xxx", "xxx", "xxx"])',
 	\ '/.*',
 	\ '2',
-	\ ], 'Xhlsearch_script')
+	\ ], 'Xhlsearch_script', 'D')
   let buf = RunVimInTerminal('-S Xhlsearch_script', {'rows': 6, 'cols': 50})
   call VerifyScreenDump(buf, 'Test_hlsearch_1', {})
 
@@ -1022,7 +1017,6 @@ func Test_hlsearch_dump()
   call VerifyScreenDump(buf, 'Test_hlsearch_2', {})
 
   call StopVimInTerminal(buf)
-  call delete('Xhlsearch_script')
 endfunc
 
 func Test_hlsearch_and_visual()
@@ -1035,14 +1029,13 @@ func Test_hlsearch_and_visual()
         \ 'hi Search cterm=bold',
 	\ '/yyy',
 	\ 'call cursor(1, 6)',
-	\ ], 'Xhlvisual_script')
+	\ ], 'Xhlvisual_script', 'D')
   let buf = RunVimInTerminal('-S Xhlvisual_script', {'rows': 6, 'cols': 40})
   call term_sendkeys(buf, "vjj")
   call VerifyScreenDump(buf, 'Test_hlsearch_visual_1', {})
   call term_sendkeys(buf, "\<Esc>")
 
   call StopVimInTerminal(buf)
-  call delete('Xhlvisual_script')
 endfunc
 
 func Test_hlsearch_block_visual_match()
@@ -1052,7 +1045,7 @@ func Test_hlsearch_block_visual_match()
     set hlsearch
     call setline(1, ['aa', 'bbbb', 'cccccc'])
   END
-  call writefile(lines, 'Xhlsearch_block')
+  call writefile(lines, 'Xhlsearch_block', 'D')
   let buf = RunVimInTerminal('-S Xhlsearch_block', {'rows': 9, 'cols': 60})
 
   call term_sendkeys(buf, "G\<C-V>$kk\<Esc>")
@@ -1062,7 +1055,6 @@ func Test_hlsearch_block_visual_match()
   call VerifyScreenDump(buf, 'Test_hlsearch_block_visual_match', {})
 
   call StopVimInTerminal(buf)
-  call delete('Xhlsearch_block')
 endfunc
 
 func Test_incsearch_substitute()
@@ -1108,7 +1100,7 @@ func Test_hlsearch_cursearch()
     hi Search ctermbg=yellow
     hi CurSearch ctermbg=blue
   END
-  call writefile(lines, 'Xhlsearch_cursearch')
+  call writefile(lines, 'Xhlsearch_cursearch', 'D')
   let buf = RunVimInTerminal('-S Xhlsearch_cursearch', {'rows': 9, 'cols': 60})
 
   call term_sendkeys(buf, "gg/foo\<CR>")
@@ -1146,7 +1138,6 @@ func Test_hlsearch_cursearch()
   call VerifyScreenDump(buf, 'Test_hlsearch_cursearch_changed_1', {})
 
   call StopVimInTerminal(buf)
-  call delete('Xhlsearch_cursearch')
 endfunc
 
 " Similar to Test_incsearch_substitute() but with a screendump halfway.
@@ -1161,7 +1152,7 @@ func Test_incsearch_substitute_dump()
 	\ 'endfor',
 	\ 'call setline(11, "bar 11")',
 	\ '3',
-	\ ], 'Xis_subst_script')
+	\ ], 'Xis_subst_script', 'D')
   let buf = RunVimInTerminal('-S Xis_subst_script', {'rows': 9, 'cols': 70})
   " Give Vim a chance to redraw to get rid of the spaces in line 2 caused by
   " the 'ambiwidth' check.
@@ -1256,7 +1247,6 @@ func Test_incsearch_substitute_dump()
   call term_sendkeys(buf, "<Esc>")
 
   call StopVimInTerminal(buf)
-  call delete('Xis_subst_script')
 endfunc
 
 func Test_incsearch_highlighting()
@@ -1266,7 +1256,7 @@ func Test_incsearch_highlighting()
   call writefile([
 	\ 'set incsearch hlsearch',
 	\ 'call setline(1, "hello/there")',
-	\ ], 'Xis_subst_hl_script')
+	\ ], 'Xis_subst_hl_script', 'D')
   let buf = RunVimInTerminal('-S Xis_subst_hl_script', {'rows': 4, 'cols': 20})
   " Give Vim a chance to redraw to get rid of the spaces in line 2 caused by
   " the 'ambiwidth' check.
@@ -1279,7 +1269,6 @@ func Test_incsearch_highlighting()
   call term_sendkeys(buf, "<Esc>")
 
   call StopVimInTerminal(buf)
-  call delete('Xis_subst_hl_script')
 endfunc
 
 func Test_incsearch_with_change()
@@ -1291,7 +1280,7 @@ func Test_incsearch_with_change()
 	\ 'set incsearch hlsearch scrolloff=0',
 	\ 'call setline(1, ["one", "two ------ X", "three"])',
 	\ 'call timer_start(200, { _ -> setline(2, "x")})',
-	\ ], 'Xis_change_script')
+	\ ], 'Xis_change_script', 'D')
   let buf = RunVimInTerminal('-S Xis_change_script', {'rows': 9, 'cols': 70})
   " Give Vim a chance to redraw to get rid of the spaces in line 2 caused by
   " the 'ambiwidth' check.
@@ -1303,7 +1292,6 @@ func Test_incsearch_with_change()
   call term_sendkeys(buf, "\<Esc>")
 
   call StopVimInTerminal(buf)
-  call delete('Xis_change_script')
 endfunc
 
 " Similar to Test_incsearch_substitute_dump() for :sort
@@ -1314,7 +1302,7 @@ func Test_incsearch_sort_dump()
   call writefile([
 	\ 'set incsearch hlsearch scrolloff=0',
 	\ 'call setline(1, ["another one 2", "that one 3", "the one 1"])',
-	\ ], 'Xis_sort_script')
+	\ ], 'Xis_sort_script', 'D')
   let buf = RunVimInTerminal('-S Xis_sort_script', {'rows': 9, 'cols': 70})
   " Give Vim a chance to redraw to get rid of the spaces in line 2 caused by
   " the 'ambiwidth' check.
@@ -1329,7 +1317,6 @@ func Test_incsearch_sort_dump()
   call term_sendkeys(buf, "\<Esc>")
 
   call StopVimInTerminal(buf)
-  call delete('Xis_sort_script')
 endfunc
 
 " Similar to Test_incsearch_substitute_dump() for :vimgrep famiry
@@ -1340,7 +1327,7 @@ func Test_incsearch_vimgrep_dump()
   call writefile([
 	\ 'set incsearch hlsearch scrolloff=0',
 	\ 'call setline(1, ["another one 2", "that one 3", "the one 1"])',
-	\ ], 'Xis_vimgrep_script')
+	\ ], 'Xis_vimgrep_script', 'D')
   let buf = RunVimInTerminal('-S Xis_vimgrep_script', {'rows': 9, 'cols': 70})
   " Give Vim a chance to redraw to get rid of the spaces in line 2 caused by
   " the 'ambiwidth' check.
@@ -1368,7 +1355,6 @@ func Test_incsearch_vimgrep_dump()
   call term_sendkeys(buf, "\<Esc>")
 
   call StopVimInTerminal(buf)
-  call delete('Xis_vimgrep_script')
 endfunc
 
 func Test_keep_last_search_pattern()
@@ -1492,11 +1478,9 @@ endfunc
 func Test_no_last_substitute_pat()
   " Use viminfo to set the last search pattern to a string and make the last
   " substitute pattern the most recent used and make it empty (NULL).
-  call writefile(['~MSle0/bar', '~MSle0~&'], 'Xviminfo')
+  call writefile(['~MSle0/bar', '~MSle0~&'], 'Xviminfo', 'D')
   rviminfo! Xviminfo
   call assert_fails('normal n', 'E35:')
-
-  call delete('Xviminfo')
 endfunc
 
 func Test_search_Ctrl_L_combining()
@@ -1739,12 +1723,11 @@ func Test_search_with_no_last_pat()
     call writefile(v:errors, 'Xresult')
     qall!
   [SCRIPT]
-  call writefile(lines, 'Xscript')
+  call writefile(lines, 'Xscript', 'D')
 
   if RunVim([], [], '--clean -S Xscript')
     call assert_equal([], readfile('Xresult'))
   endif
-  call delete('Xscript')
   call delete('Xresult')
 endfunc
 
@@ -1762,11 +1745,10 @@ func Test_search_tilde_pat()
     call writefile(v:errors, 'Xresult')
     qall!
   [SCRIPT]
-  call writefile(lines, 'Xscript')
+  call writefile(lines, 'Xscript', 'D')
   if RunVim([], [], '--clean -S Xscript')
     call assert_equal([], readfile('Xresult'))
   endif
-  call delete('Xscript')
   call delete('Xresult')
 endfunc
 
@@ -2012,7 +1994,7 @@ func Test_incsearch_highlighting_newline()
     set incsearch nohls
     call setline(1, ['test', 'xxx'])
   [CODE]
-  call writefile(commands, 'Xincsearch_nl')
+  call writefile(commands, 'Xincsearch_nl', 'D')
   let buf = RunVimInTerminal('-S Xincsearch_nl', {'rows': 5, 'cols': 10})
   call term_sendkeys(buf, '/test')
   call VerifyScreenDump(buf, 'Test_incsearch_newline1', {})
@@ -2028,7 +2010,6 @@ func Test_incsearch_highlighting_newline()
   call StopVimInTerminal(buf)
 
   " clean up
-  call delete('Xincsearch_nl')
   call test_override("char_avail", 0)
   bw
 endfunc
@@ -2044,7 +2025,7 @@ func Test_incsearch_substitute_dump2()
 	\ 'endfor',
 	\ 'call setline(5, "abc|def")',
 	\ '3',
-	\ ], 'Xis_subst_script2')
+	\ ], 'Xis_subst_script2', 'D')
   let buf = RunVimInTerminal('-S Xis_subst_script2', {'rows': 9, 'cols': 70})
 
   call term_sendkeys(buf, ':%s/\vabc|')
@@ -2059,7 +2040,6 @@ func Test_incsearch_substitute_dump2()
 
 
   call StopVimInTerminal(buf)
-  call delete('Xis_subst_script2')
 endfunc
 
 func Test_pattern_is_uppercase_smartcase()
@@ -2146,11 +2126,10 @@ func Test_search_with_invalid_range()
     5/
     c
   END
-  call writefile(lines, 'Xrangesearch')
+  call writefile(lines, 'Xrangesearch', 'D')
   source Xrangesearch
 
   bwipe!
-  call delete('Xrangesearch')
 endfunc
 
 
diff --git a/src/testdir/test_search_stat.vim b/src/testdir/test_search_stat.vim
index 71e050c66d..b8509ba055 100644
--- a/src/testdir/test_search_stat.vim
+++ b/src/testdir/test_search_stat.vim
@@ -287,7 +287,7 @@ func Test_searchcount_in_statusline()
     set hlsearch
     set laststatus=2 statusline+=%{TestSearchCount()}
   END
-  call writefile(lines, 'Xsearchstatusline')
+  call writefile(lines, 'Xsearchstatusline', 'D')
   let buf = RunVimInTerminal('-S Xsearchstatusline', #{rows: 10})
   call TermWait(buf)
   call term_sendkeys(buf, "/something")
@@ -295,7 +295,6 @@ func Test_searchcount_in_statusline()
 
   call term_sendkeys(buf, "\<Esc>")
   call StopVimInTerminal(buf)
-  call delete('Xsearchstatusline')
 endfunc
 
 func Test_search_stat_foldopen()
@@ -309,7 +308,7 @@ func Test_search_stat_foldopen()
     call cursor(1,1)
     norm n
   END
-  call writefile(lines, 'Xsearchstat1')
+  call writefile(lines, 'Xsearchstat1', 'D')
 
   let buf = RunVimInTerminal('-S Xsearchstat1', #{rows: 10})
   call VerifyScreenDump(buf, 'Test_searchstat_3', {})
@@ -321,7 +320,6 @@ func Test_search_stat_foldopen()
   call VerifyScreenDump(buf, 'Test_searchstat_3', {})
 
   call StopVimInTerminal(buf)
-  call delete('Xsearchstat1')
 endfunc
 
 func! Test_search_stat_screendump()
@@ -338,7 +336,7 @@ func! Test_search_stat_screendump()
     call cursor(1,1)
     norm n
   END
-  call writefile(lines, 'Xsearchstat')
+  call writefile(lines, 'Xsearchstat', 'D')
   let buf = RunVimInTerminal('-S Xsearchstat', #{rows: 10})
   call VerifyScreenDump(buf, 'Test_searchstat_1', {})
 
@@ -347,7 +345,6 @@ func! Test_search_stat_screendump()
   call VerifyScreenDump(buf, 'Test_searchstat_2', {})
 
   call StopVimInTerminal(buf)
-  call delete('Xsearchstat')
 endfunc
 
 func Test_search_stat_then_gd()
@@ -358,7 +355,7 @@ func Test_search_stat_then_gd()
     set shortmess-=S
     set hlsearch
   END
-  call writefile(lines, 'Xsearchstatgd')
+  call writefile(lines, 'Xsearchstatgd', 'D')
 
   let buf = RunVimInTerminal('-S Xsearchstatgd', #{rows: 10})
   call term_sendkeys(buf, "/dog\<CR>")
@@ -368,7 +365,6 @@ func Test_search_stat_then_gd()
   call VerifyScreenDump(buf, 'Test_searchstatgd_2', {})
 
   call StopVimInTerminal(buf)
-  call delete('Xsearchstatgd')
 endfunc
 
 func Test_search_stat_and_incsearch()
@@ -392,7 +388,7 @@ func Test_search_stat_and_incsearch()
 
     set tabline=%!MyTabLine()
   END
-  call writefile(lines, 'Xsearchstat_inc')
+  call writefile(lines, 'Xsearchstat_inc', 'D')
 
   let buf = RunVimInTerminal('-S Xsearchstat_inc', #{rows: 10})
   call term_sendkeys(buf, "/abc")
@@ -411,7 +407,6 @@ func Test_search_stat_and_incsearch()
   call TermWait(buf)
 
   call StopVimInTerminal(buf)
-  call delete('Xsearchstat_inc')
 endfunc
 
 
diff --git a/src/testdir/test_shell.vim b/src/testdir/test_shell.vim
index a194f3b68c..cacb02b1b8 100644
--- a/src/testdir/test_shell.vim
+++ b/src/testdir/test_shell.vim
@@ -202,7 +202,7 @@ func Test_shellxquote()
   let save_sxq = &shellxquote
   let save_sxe = &shellxescape
 
-  call writefile(['#!/bin/sh', 'echo "Cmd: [$*]" > Xlog'], 'Xtestshell')
+  call writefile(['#!/bin/sh', 'echo "Cmd: [$*]" > Xlog'], 'Xtestshell', 'D')
   call setfperm('Xtestshell', "r-x------")
   set shell=./Xtestshell
 
@@ -226,7 +226,6 @@ func Test_shellxquote()
   let &shell = save_shell
   let &shellxquote = save_sxq
   let &shellxescape = save_sxe
-  call delete('Xtestshell')
   call delete('Xlog')
 endfunc
 
diff --git a/src/testdir/test_shortpathname.vim b/src/testdir/test_shortpathname.vim
index 79b7899c86..59646308e9 100644
--- a/src/testdir/test_shortpathname.vim
+++ b/src/testdir/test_shortpathname.vim
@@ -42,7 +42,7 @@ func Test_ColonEight()
   let file2 = dir2 . '/z.txt'
   let nofile2 = dir2 . '/zz.txt'
 
-  call mkdir(dir1)
+  call mkdir(dir1, 'D')
   let resdir1 = substitute(fnamemodify(dir1, ':p:8'), '/$', '', '')
   call assert_match('\V\^c:/XX\x\x\x\x~1.Y\$', resdir1)
 
@@ -52,9 +52,9 @@ func Test_ColonEight()
   let resfile2 = resdir2 . '/z.txt'
   let resnofile2 = resdir2 . '/zz.txt'
 
-  call mkdir(dir2)
-  call writefile([], file1)
-  call writefile([], file2)
+  call mkdir(dir2, 'D')
+  call writefile([], file1, 'D')
+  call writefile([], file2, 'D')
 
   call TestIt(file1, ':p:8', resfile1)
   call TestIt(nofile1, ':p:8', resnofile1)
@@ -73,10 +73,6 @@ func Test_ColonEight()
   call TestIt(nofile2, ':~:8', '~' . strpart(resnofile2, strlen(resdir1)))
 
   cd c:/
-  call delete(file2)
-  call delete(file1)
-  call delete(dir2, 'd')
-  call delete(dir1, 'd')
 
   call chdir(save_dir)
 endfunc
@@ -86,16 +82,13 @@ func Test_ColonEight_MultiByte()
 
   let file = dir . '/日本語のファイル.txt'
 
-  call mkdir(dir)
-  call writefile([], file)
+  call mkdir(dir, 'D')
+  call writefile([], file, 'D')
 
   let sfile = fnamemodify(file, ':8')
 
   call assert_notequal(file, sfile)
   call assert_match('\~', sfile)
-
-  call delete(file)
-  call delete(dir, 'd')
 endfunc
 
 func Test_ColonEight_notexists()
diff --git a/src/testdir/test_signals.vim b/src/testdir/test_signals.vim
index ea25ae1091..c37ea2aaf3 100644
--- a/src/testdir/test_signals.vim
+++ b/src/testdir/test_signals.vim
@@ -117,7 +117,7 @@ func Test_signal_TSTP()
     au VimSuspend * call writefile(["VimSuspend triggered"], "XautoOut1", "as")
     au VimResume * call writefile(["VimResume triggered"], "XautoOut2", "as")
   END
-  call writefile(lines, 'XsetupAucmd')
+  call writefile(lines, 'XsetupAucmd', 'D')
 
   let buf = RunVimInTerminal('-S XsetupAucmd Xsig_TERM', {'rows': 6})
   let pid_vim = term_getjob(buf)->job_info().process
@@ -147,7 +147,6 @@ func Test_signal_TSTP()
 
   %bwipe!
   call delete('.Xsig_TERM.swp')
-  call delete('XsetupAucmd')
   call delete('XautoOut1')
   call delete('XautoOut2')
 endfunc
@@ -176,7 +175,7 @@ func Test_deadly_signal_TERM()
     au VimLeave * call writefile(["VimLeave triggered"], "XautoOut", "as")
     au VimLeavePre * call writefile(["VimLeavePre triggered"], "XautoOut", "as")
   END
-  call writefile(lines, 'XsetupAucmd')
+  call writefile(lines, 'XsetupAucmd', 'D')
 
   let buf = RunVimInTerminal('-S XsetupAucmd Xsig_TERM', {'rows': 6})
   let pid_vim = term_getjob(buf)->job_info().process
@@ -200,7 +199,6 @@ func Test_deadly_signal_TERM()
 
   %bwipe!
   call delete('.Xsig_TERM.swp')
-  call delete('XsetupAucmd')
   call delete('XautoOut')
 endfunc
 
diff --git a/src/testdir/test_signs.vim b/src/testdir/test_signs.vim
index 3a99a9b8fb..abf70cd520 100644
--- a/src/testdir/test_signs.vim
+++ b/src/testdir/test_signs.vim
@@ -248,8 +248,8 @@ func Test_sign_completion()
                 \ 'SpellLocal SpellRare', @:)
   endfor
 
-  call writefile(repeat(["Sun is shining"], 30), "XsignOne")
-  call writefile(repeat(["Sky is blue"], 30), "XsignTwo")
+  call writefile(repeat(["Sun is shining"], 30), "XsignOne", 'D')
+  call writefile(repeat(["Sky is blue"], 30), "XsignTwo", 'D')
   call feedkeys(":sign define Sign icon=Xsig\<C-A>\<C-B>\"\<CR>", 'tx')
   call assert_equal('"sign define Sign icon=XsignOne XsignTwo', @:)
 
@@ -326,8 +326,6 @@ func Test_sign_completion()
   sign undefine Sign1
   sign undefine Sign2
   enew
-  call delete('XsignOne')
-  call delete('XsignTwo')
 endfunc
 
 func Test_sign_invalid_commands()
@@ -470,7 +468,7 @@ func Test_sign_funcs()
   call assert_fails('call sign_getdefined({})', 'E731:')
 
   " Tests for sign_place()
-  call writefile(repeat(["Sun is shining"], 30), "Xsign")
+  call writefile(repeat(["Sun is shining"], 30), "Xsign", 'D')
   edit Xsign
 
   call assert_equal(10, sign_place(10, '', 'sign1', 'Xsign',
@@ -576,7 +574,6 @@ func Test_sign_funcs()
 	      \ 'priority' : 10}]}],
 	      \ sign_getplaced('%', {'lnum' : 22}))
 
-  call delete("Xsign")
   call sign_unplace('*')
   call sign_undefine()
   enew | only
@@ -589,7 +586,7 @@ func Test_sign_group()
   call sign_unplace('*')
   call sign_undefine()
 
-  call writefile(repeat(["Sun is shining"], 30), "Xsign")
+  call writefile(repeat(["Sun is shining"], 30), "Xsign", 'D')
 
   let attr = {'text' : '=>', 'linehl' : 'Search', 'texthl' : 'Error'}
   call assert_equal(0, sign_define("sign1", attr))
@@ -829,7 +826,6 @@ func Test_sign_group()
   " Error cases
   call assert_fails("sign place 3 group= name=sign1 buffer=" . bnum, 'E474:')
 
-  call delete("Xsign")
   call sign_unplace('*')
   call sign_undefine()
   enew | only
@@ -872,8 +868,8 @@ func Test_sign_unplace()
   call sign_undefine()
 
   " Create two files and define signs
-  call writefile(repeat(["Sun is shining"], 30), "Xsign1")
-  call writefile(repeat(["It is beautiful"], 30), "Xsign2")
+  call writefile(repeat(["Sun is shining"], 30), "Xsign1", 'D')
+  call writefile(repeat(["It is beautiful"], 30), "Xsign2", 'D')
 
   let attr = {'text' : '=>', 'linehl' : 'Search', 'texthl' : 'Error'}
   call sign_define("sign1", attr)
@@ -1182,8 +1178,6 @@ func Test_sign_unplace()
   call sign_unplace('*')
   call sign_undefine()
   enew | only
-  call delete("Xsign1")
-  call delete("Xsign2")
 endfunc
 
 " Tests for auto-generating the sign identifier.
@@ -1195,7 +1189,7 @@ func Test_aaa_sign_id_autogen()
   let attr = {'text' : '=>', 'linehl' : 'Search', 'texthl' : 'Error'}
   call assert_equal(0, sign_define("sign1", attr))
 
-  call writefile(repeat(["Sun is shining"], 30), "Xsign")
+  call writefile(repeat(["Sun is shining"], 30), "Xsign", 'D')
   edit Xsign
 
   call assert_equal(1, sign_place(0, '', 'sign1', 'Xsign',
@@ -1217,7 +1211,6 @@ func Test_aaa_sign_id_autogen()
   call assert_equal(10,
 	      \ sign_getplaced('Xsign', {'id' : 1})[0].signs[0].lnum)
 
-  call delete("Xsign")
   call sign_unplace('*')
   call sign_undefine()
   enew | only
@@ -1235,7 +1228,7 @@ func Test_sign_priority()
   call sign_define("sign3", attr)
 
   " Place three signs with different priority in the same line
-  call writefile(repeat(["Sun is shining"], 30), "Xsign")
+  call writefile(repeat(["Sun is shining"], 30), "Xsign", 'D')
   edit Xsign
 
   call sign_place(1, 'g1', 'sign1', 'Xsign',
@@ -1590,12 +1583,11 @@ func Test_sign_priority()
   call sign_unplace('*')
   call sign_undefine()
   enew | only
-  call delete("Xsign")
 endfunc
 
 " Tests for memory allocation failures in sign functions
 func Test_sign_memfailures()
-  call writefile(repeat(["Sun is shining"], 30), "Xsign")
+  call writefile(repeat(["Sun is shining"], 30), "Xsign", 'D')
   edit Xsign
 
   call test_alloc_fail(GetAllocId('sign_getdefined'), 0, 0)
@@ -1632,7 +1624,6 @@ func Test_sign_memfailures()
   call sign_unplace('*')
   call sign_undefine()
   enew | only
-  call delete("Xsign")
 endfunc
 
 " Test for auto-adjusting the line number of a placed sign.
@@ -1789,7 +1780,7 @@ func Test_sign_cursor_position()
 	redraw
    	sign place 10 line=2 name=s1
   END
-  call writefile(lines, 'XtestSigncolumn')
+  call writefile(lines, 'XtestSigncolumn', 'D')
   let buf = RunVimInTerminal('-S XtestSigncolumn', {'rows': 6})
   call VerifyScreenDump(buf, 'Test_sign_cursor_1', {})
 
@@ -1823,7 +1814,6 @@ func Test_sign_cursor_position()
 
   " clean up
   call StopVimInTerminal(buf)
-  call delete('XtestSigncolumn')
 endfunc
 
 " Return the 'len' characters in screen starting from (row,col)
@@ -1942,7 +1932,7 @@ endfunc
 
 " Test for managing multiple signs using the sign functions
 func Test_sign_funcs_multi()
-  call writefile(repeat(["Sun is shining"], 30), "Xsign")
+  call writefile(repeat(["Sun is shining"], 30), "Xsign", 'D')
   edit Xsign
   let bnum = bufnr('')
 
@@ -2054,7 +2044,6 @@ func Test_sign_funcs_multi()
   call sign_unplace('*')
   call sign_undefine()
   enew!
-  call delete("Xsign")
 endfunc
 
 func Test_sign_null_list()
diff --git a/src/testdir/test_sort.vim b/src/testdir/test_sort.vim
index 124948e269..a2731a8004 100644
--- a/src/testdir/test_sort.vim
+++ b/src/testdir/test_sort.vim
@@ -1520,11 +1520,10 @@ func Test_sort_with_no_last_search_pat()
     call writefile(v:errors, 'Xresult')
     qall!
   [SCRIPT]
-  call writefile(lines, 'Xscript')
+  call writefile(lines, 'Xscript', 'D')
   if RunVim([], [], '--clean -S Xscript')
     call assert_equal([], readfile('Xresult'))
   endif
-  call delete('Xscript')
   call delete('Xresult')
 endfunc
 
diff --git a/src/testdir/test_source.vim b/src/testdir/test_source.vim
index 51de0e32d6..3692eee5fa 100644
--- a/src/testdir/test_source.vim
+++ b/src/testdir/test_source.vim
@@ -51,12 +51,10 @@ endfunc
 " When deleting a file and immediately creating a new one the inode may be
 " recycled.  Vim should not recognize it as the same script.
 func Test_different_script()
-  call writefile(['let s:var = "asdf"'], 'XoneScript')
+  call writefile(['let s:var = "asdf"'], 'XoneScript', 'D')
   source XoneScript
-  call delete('XoneScript')
-  call writefile(['let g:var = s:var'], 'XtwoScript')
+  call writefile(['let g:var = s:var'], 'XtwoScript', 'D')
   call assert_fails('source XtwoScript', 'E121:')
-  call delete('XtwoScript')
 endfunc
 
 " When sourcing a vim script, shebang should be ignored.
diff --git a/src/testdir/test_source_utf8.vim b/src/testdir/test_source_utf8.vim
index d22ce8f66d..bd7cd8d248 100644
--- a/src/testdir/test_source_utf8.vim
+++ b/src/testdir/test_source_utf8.vim
@@ -43,7 +43,7 @@ func Test_source_ctrl_v()
         \ "map __3 asd\<C-V>\<C-V>",
         \ "map __4 asd\<C-V>\<C-V>\<C-V>",
         \ "map __5 asd\<C-V>\<C-V>\<C-V>",
-        \ ], 'Xtestfile')
+        \ ], 'Xtestfile', 'D')
   source Xtestfile
   enew!
   exe "normal __1\<Esc>\<Esc>__2\<Esc>__3\<Esc>\<Esc>__4\<Esc>__5\<Esc>"
@@ -53,7 +53,6 @@ func Test_source_ctrl_v()
         \ getline(1, 2))
 
   enew!
-  call delete('Xtestfile')
   unmap __1
   unmap __2
   unmap __3
diff --git a/src/testdir/test_spell.vim b/src/testdir/test_spell.vim
index 3f77695c23..4a7a46c5b3 100644
--- a/src/testdir/test_spell.vim
+++ b/src/testdir/test_spell.vim
@@ -762,8 +762,8 @@ endfunc
 func Test_zz_sal_and_addition()
   set enc=latin1
   set spellfile=
-  call writefile(g:test_data_dic1, "Xtest.dic")
-  call writefile(g:test_data_aff_sal, "Xtest.aff")
+  call writefile(g:test_data_dic1, "Xtest.dic", 'D')
+  call writefile(g:test_data_aff_sal, "Xtest.aff", 'D')
   mkspell! Xtest Xtest
   set spl=Xtest.latin1.spl spell
   call assert_equal('kbltykk', soundfold('goobledygoook'))
@@ -771,7 +771,7 @@ func Test_zz_sal_and_addition()
   call assert_equal('*fls kswts tl', soundfold('oeverloos gezwets edale'))
 
   "also use an addition file
-  call writefile(["/regions=usgbnz", "elequint/2", "elekwint/3"], "Xtest.latin1.add")
+  call writefile(["/regions=usgbnz", "elequint/2", "elekwint/3"], "Xtest.latin1.add", 'D')
   mkspell! Xtest.latin1.add.spl Xtest.latin1.add
 
   bwipe!
@@ -808,10 +808,9 @@ endfunc
 
 func Test_region_error()
   messages clear
-  call writefile(["/regions=usgbnz", "elequint/0"], "Xtest.latin1.add")
+  call writefile(["/regions=usgbnz", "elequint/0"], "Xtest.latin1.add", 'D')
   mkspell! Xtest.latin1.add.spl Xtest.latin1.add
   call assert_match('Invalid region nr in Xtest.latin1.add line 2: 0', execute('messages'))
-  call delete('Xtest.latin1.add')
   call delete('Xtest.latin1.add.spl')
 endfunc
 
diff --git a/src/testdir/test_spell_utf8.vim b/src/testdir/test_spell_utf8.vim
index 91ada1ed38..bb2c354a3d 100644
--- a/src/testdir/test_spell_utf8.vim
+++ b/src/testdir/test_spell_utf8.vim
@@ -726,8 +726,8 @@ endfunc
 " Test with SAL instead of SOFO items; test automatic reloading
 func Test_spell_sal_and_addition()
   set spellfile=
-  call writefile(g:test_data_dic1, "Xtest.dic")
-  call writefile(g:test_data_aff_sal, "Xtest.aff")
+  call writefile(g:test_data_dic1, "Xtest.dic", 'D')
+  call writefile(g:test_data_aff_sal, "Xtest.aff", 'D')
   mkspell! Xtest Xtest
   set spl=Xtest.utf-8.spl spell
   call assert_equal('kbltykk', soundfold('goobledygoook'))
@@ -735,7 +735,7 @@ func Test_spell_sal_and_addition()
   call assert_equal('*fls kswts tl', soundfold('oeverloos gezwets edale'))
 
   "also use an addition file
-  call writefile(["/regions=usgbnz", "elequint/2", "elekwint/3"], "Xtest.utf-8.add")
+  call writefile(["/regions=usgbnz", "elequint/2", "elekwint/3"], "Xtest.utf-8.add", 'D')
   mkspell! Xtest.utf-8.add.spl Xtest.utf-8.add
 
   bwipe!
diff --git a/src/testdir/test_spellfile.vim b/src/testdir/test_spellfile.vim
index 28e69bdc5d..d8d954b3bf 100644
--- a/src/testdir/test_spellfile.vim
+++ b/src/testdir/test_spellfile.vim
@@ -212,7 +212,7 @@ endfunc
 " The spell file format is described in spellfile.c
 func Test_spellfile_format_error()
   let save_rtp = &rtp
-  call mkdir('Xtest/spell', 'p')
+  call mkdir('Xtest/spell', 'pR')
   let splfile = './Xtest/spell/Xtest.utf-8.spl'
 
   " empty spell file
@@ -384,13 +384,12 @@ func Test_spellfile_format_error()
   call Spellfile_Test(0zFF00000000000000000000000201010000, 'E759:')
 
   let &rtp = save_rtp
-  call delete('Xtest', 'rf')
 endfunc
 
 " Test for format errors in suggest file
 func Test_sugfile_format_error()
   let save_rtp = &rtp
-  call mkdir('Xtest/spell', 'p')
+  call mkdir('Xtest/spell', 'pR')
   let splfile = './Xtest/spell/Xtest.utf-8.spl'
   let sugfile = './Xtest/spell/Xtest.utf-8.sug'
 
@@ -473,7 +472,6 @@ func Test_sugfile_format_error()
   set nospell spelllang&
 
   let &rtp = save_rtp
-  call delete('Xtest', 'rf')
 endfunc
 
 " Test for using :mkspell to create a spell file from a list of words
@@ -486,7 +484,7 @@ func Test_wordlist_dic()