patch 8.0.1630: trimming white space is not that easy
Problem: Trimming white space is not that easy.
Solution: Add the trim() function. (Bukn, closes #1280)
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index ffc3bc3..49e5d1f 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -876,3 +876,26 @@
let &shell = save_shell
endfunc
+
+func Test_trim()
+ call assert_equal("Testing", trim(" \t\r\r\x0BTesting \t\n\r\n\t\x0B\x0B"))
+ call assert_equal("Testing", trim(" \t \r\r\n\n\x0BTesting \t\n\r\n\t\x0B\x0B"))
+ call assert_equal("RESERVE", trim("xyz \twwRESERVEzyww \t\t", " wxyz\t"))
+ call assert_equal("wRE \tSERVEzyww", trim("wRE \tSERVEzyww"))
+ call assert_equal("abcd\t xxxx tail", trim(" \tabcd\t xxxx tail"))
+ call assert_equal("\tabcd\t xxxx tail", trim(" \tabcd\t xxxx tail", " "))
+ call assert_equal(" \tabcd\t xxxx tail", trim(" \tabcd\t xxxx tail", "abx"))
+ call assert_equal("RESERVE", trim("你RESERVE好", "你好"))
+ call assert_equal("您R E SER V E早", trim("你好您R E SER V E早好你你", "你好"))
+ call assert_equal("你好您R E SER V E早好你你", trim(" \n\r\r 你好您R E SER V E早好你你 \t \x0B", ))
+ call assert_equal("您R E SER V E早好你你 \t \x0B", trim(" 你好您R E SER V E早好你你 \t \x0B", " 你好"))
+ call assert_equal("您R E SER V E早好你你 \t \x0B", trim(" tteesstttt你好您R E SER V E早好你你 \t \x0B ttestt", " 你好tes"))
+ call assert_equal("您R E SER V E早好你你 \t \x0B", trim(" tteesstttt你好您R E SER V E早好你你 \t \x0B ttestt", " 你你你好好好tttsses"))
+ call assert_equal("留下", trim("这些些不要这些留下这些", "这些不要"))
+ call assert_equal("", trim("", ""))
+ call assert_equal("a", trim("a", ""))
+ call assert_equal("", trim("", "a"))
+
+ let chars = join(map(range(1, 0x20) + [0xa0], {n -> nr2char(n)}), '')
+ call assert_equal("x", trim(chars . "x" . chars))
+endfunc