neovim/src/nvim/testdir/test_vimscript.vim

" Test various aspects of the Vim script language.
" Most of this was formerly in test49.

source check.vim
source shared.vim

"-------------------------------------------------------------------------------
" Test environment							    {{{1
"-------------------------------------------------------------------------------

com!		   XpathINIT  let g:Xpath = ''
com! -nargs=1 -bar Xpath      let g:Xpath = g:Xpath . <args>

" Append a message to the "messages" file
func Xout(text)
    split messages
    $put =a:text
    wq
endfunc

com! -nargs=1	     Xout     call Xout(<args>)

" MakeScript() - Make a script file from a function.			    {{{2
"
" Create a script that consists of the body of the function a:funcname.
" Replace any ":return" by a ":finish", any argument variable by a global
" variable, and every ":call" by a ":source" for the next following argument
" in the variable argument list.  This function is useful if similar tests are
" to be made for a ":return" from a function call or a ":finish" in a script
" file.
func MakeScript(funcname, ...)
    let script = tempname()
    execute "redir! >" . script
    execute "function" a:funcname
    redir END
    execute "edit" script
    " Delete the "function" and the "endfunction" lines.  Do not include the
    " word "function" in the pattern since it might be translated if LANG is
    " set.  When MakeScript() is being debugged, this deletes also the debugging
    " output of its line 3 and 4.
    exec '1,/.*' . a:funcname . '(.*)/d'
    /^\d*\s*endfunction\>/,$d
    %s/^\d*//e
    %s/return/finish/e
    %s/\<a:\(\h\w*\)/g:\1/ge
    normal gg0
    let cnt = 0
    while search('\<call\s*\%(\u\|s:\)\w*\s*(.*)', 'W') > 0
	let cnt = cnt + 1
	s/\<call\s*\%(\u\|s:\)\w*\s*(.*)/\='source ' . a:{cnt}/
    endwhile
    g/^\s*$/d
    write
    bwipeout
    return script
endfunc

" ExecAsScript - Source a temporary script made from a function.	    {{{2
"
" Make a temporary script file from the function a:funcname, ":source" it, and
" delete it afterwards.  However, if an exception is thrown the file may remain,
" the caller should call DeleteTheScript() afterwards.
let s:script_name = ''
function! ExecAsScript(funcname)
    " Make a script from the function passed as argument.
    let s:script_name = MakeScript(a:funcname)

    " Source and delete the script.
    exec "source" s:script_name
    call delete(s:script_name)
    let s:script_name = ''
endfunction

function! DeleteTheScript()
    if s:script_name
	call delete(s:script_name)
	let s:script_name = ''
    endif
endfunc

com! -nargs=1 -bar ExecAsScript call ExecAsScript(<f-args>)


"-------------------------------------------------------------------------------
" Test 1:   :endwhile in function					    {{{1
"
"	    Detect if a broken loop is (incorrectly) reactivated by the
"	    :endwhile.  Use a :return to prevent an endless loop, and make
"	    this test first to get a meaningful result on an error before other
"	    tests will hang.
"-------------------------------------------------------------------------------

function! T1_F()
    Xpath 'a'
    let first = 1
    while 1
	Xpath 'b'
	if first
	    Xpath 'c'
	    let first = 0
	    break
	else
	    Xpath 'd'
	    return
	endif
    endwhile
endfunction

function! T1_G()
    Xpath 'h'
    let first = 1
    while 1
	Xpath 'i'
	if first
	    Xpath 'j'
	    let first = 0
	    break
	else
	    Xpath 'k'
	    return
	endif
	if 1	" unmatched :if
    endwhile
endfunction

func Test_endwhile_function()
  XpathINIT
  call T1_F()
  Xpath 'F'

  try
    call T1_G()
  catch
    " Catch missing :endif
    call assert_true(v:exception =~ 'E171')
    Xpath 'x'
  endtry
  Xpath 'G'

  call assert_equal('abcFhijxG', g:Xpath)
endfunc

"-------------------------------------------------------------------------------
" Test 2:   :endwhile in script						    {{{1
"
"	    Detect if a broken loop is (incorrectly) reactivated by the
"	    :endwhile.  Use a :finish to prevent an endless loop, and place
"	    this test before others that might hang to get a meaningful result
"	    on an error.
"
"	    This test executes the bodies of the functions T1_F and T1_G from
"	    the previous test as script files (:return replaced by :finish).
"-------------------------------------------------------------------------------

func Test_endwhile_script()
  XpathINIT
  ExecAsScript T1_F
  Xpath 'F'
  call DeleteTheScript()

  try
    ExecAsScript T1_G
  catch
    " Catch missing :endif
    call assert_true(v:exception =~ 'E171')
    Xpath 'x'
  endtry
  Xpath 'G'
  call DeleteTheScript()

  call assert_equal('abcFhijxG', g:Xpath)
endfunc

"-------------------------------------------------------------------------------
" Test 3:   :if, :elseif, :while, :continue, :break			    {{{1
"-------------------------------------------------------------------------------

function Test_if_while()
    XpathINIT
    if 1
	Xpath 'a'
	let loops = 3
	while loops > -1	    " main loop: loops == 3, 2, 1 (which breaks)
	    if loops <= 0
		let break_err = 1
		let loops = -1
	    else
		Xpath 'b' . loops
	    endif
	    if (loops == 2)
		while loops == 2 " dummy loop
		    Xpath 'c' . loops
		    let loops = loops - 1
		    continue    " stop dummy loop
		    Xpath 'd' . loops
		endwhile
		continue	    " continue main loop
		Xpath 'e' . loops
	    elseif (loops == 1)
		let p = 1
		while p	    " dummy loop
		    Xpath 'f' . loops
		    let p = 0
		    break	    " break dummy loop
		    Xpath 'g' . loops
		endwhile
		Xpath 'h' . loops
		unlet p
		break	    " break main loop
		Xpath 'i' . loops
	    endif
	    if (loops > 0)
		Xpath 'j' . loops
	    endif
	    while loops == 3    " dummy loop
		let loops = loops - 1
	    endwhile	    " end dummy loop
	endwhile		    " end main loop
	Xpath 'k'
    else
	Xpath 'l'
    endif
    Xpath 'm'
    if exists("break_err")
	Xpath 'm'
	unlet break_err
    endif

    unlet loops

    call assert_equal('ab3j3b2c2b1f1h1km', g:Xpath)
endfunc

"-------------------------------------------------------------------------------
" Test 4:   :return							    {{{1
"-------------------------------------------------------------------------------

function! T4_F()
    if 1
	Xpath 'a'
	let loops = 3
	while loops > 0				"    3:  2:     1:
	    Xpath 'b' . loops
	    if (loops == 2)
		Xpath 'c' . loops
		return
		Xpath 'd' . loops
	    endif
	    Xpath 'e' . loops
	    let loops = loops - 1
	endwhile
	Xpath 'f'
    else
	Xpath 'g'
    endif
endfunction

function Test_return()
    XpathINIT
    call T4_F()
    Xpath '4'

    call assert_equal('ab3e3b2c24', g:Xpath)
endfunction


"-------------------------------------------------------------------------------
" Test 5:   :finish							    {{{1
"
"	    This test executes the body of the function T4_F from the previous
"	    test as a script file (:return replaced by :finish).
"-------------------------------------------------------------------------------

function Test_finish()
    XpathINIT
    ExecAsScript T4_F
    Xpath '5'
    call DeleteTheScript()

    call assert_equal('ab3e3b2c25', g:Xpath)
endfunction



"-------------------------------------------------------------------------------
" Test 6:   Defining functions in :while loops				    {{{1
"
"	     Functions can be defined inside other functions.  An inner function
"	     gets defined when the outer function is executed.  Functions may
"	     also be defined inside while loops.  Expressions in braces for
"	     defining the function name are allowed.
"
"	     The functions are defined when sourcing the script, only the
"	     resulting path is checked in the test function.
"-------------------------------------------------------------------------------

XpathINIT

" The command CALL collects the argument of all its invocations in "calls"
" when used from a function (that is, when the global variable "calls" needs
" the "g:" prefix).  This is to check that the function code is skipped when
" the function is defined.  For inner functions, do so only if the outer
" function is not being executed.
"
let calls = ""
com! -nargs=1 CALL
	    \ if !exists("calls") && !exists("outer") |
	    \ let g:calls = g:calls . <args> |
	    \ endif

let i = 0
while i < 3
    let i = i + 1
    if i == 1
	Xpath 'a'
	function! F1(arg)
	    CALL a:arg
	    let outer = 1

	    let j = 0
	    while j < 1
		Xpath 'b'
		let j = j + 1
		function! G1(arg)
		    CALL a:arg
		endfunction
		Xpath 'c'
	    endwhile
	endfunction
	Xpath 'd'

	continue
    endif

    Xpath 'e' . i
    function! F{i}(i, arg)
	CALL a:arg
	let outer = 1

	if a:i == 3
	    Xpath 'f'
	endif
	let k = 0
	while k < 3
	    Xpath 'g' . k
	    let k = k + 1
	    function! G{a:i}{k}(arg)
		CALL a:arg
	    endfunction
	    Xpath 'h' . k
	endwhile
    endfunction
    Xpath 'i'

endwhile

if exists("*G1")
    Xpath 'j'
endif
if exists("*F1")
    call F1("F1")
    if exists("*G1")
       call G1("G1")
    endif
endif

if exists("G21") || exists("G22") || exists("G23")
    Xpath 'k'
endif
if exists("*F2")
    call F2(2, "F2")
    if exists("*G21")
       call G21("G21")
    endif
    if exists("*G22")
       call G22("G22")
    endif
    if exists("*G23")
       call G23("G23")
    endif
endif

if exists("G31") || exists("G32") || exists("G33")
    Xpath 'l'
endif
if exists("*F3")
    call F3(3, "F3")
    if exists("*G31")
       call G31("G31")
    endif
    if exists("*G32")
       call G32("G32")
    endif
    if exists("*G33")
       call G33("G33")
    endif
endif

Xpath 'm'

let g:test6_result = g:Xpath
let g:test6_calls = calls

unlet calls
delfunction F1
delfunction G1
delfunction F2
delfunction G21
delfunction G22
delfunction G23
delfunction G31
delfunction G32
delfunction G33

function Test_defining_functions()
    call assert_equal('ade2ie3ibcg0h1g1h2g2h3fg0h1g1h2g2h3m', g:test6_result)
    call assert_equal('F1G1F2G21G22G23F3G31G32G33', g:test6_calls)
endfunc

"-------------------------------------------------------------------------------
" Test 7:   Continuing on errors outside functions			    {{{1
"
"	    On an error outside a function, the script processing continues
"	    at the line following the outermost :endif or :endwhile.  When not
"	    inside an :if or :while, the script processing continues at the next
"	    line.
"-------------------------------------------------------------------------------

XpathINIT

if 1
    Xpath 'a'
    while 1
	Xpath 'b'
	asdf
	Xpath 'c'
	break
    endwhile | Xpath 'd'
    Xpath 'e'
endif | Xpath 'f'
Xpath 'g'

while 1
    Xpath 'h'
    if 1
	Xpath 'i'
	asdf
	Xpath 'j'
    endif | Xpath 'k'
    Xpath 'l'
    break
endwhile | Xpath 'm'
Xpath 'n'

asdf
Xpath 'o'

asdf | Xpath 'p'
Xpath 'q'

let g:test7_result = g:Xpath

func Test_error_in_script()
    call assert_equal('abghinoq', g:test7_result)
endfunc

"-------------------------------------------------------------------------------
" Test 8:   Aborting and continuing on errors inside functions		    {{{1
"
"	    On an error inside a function without the "abort" attribute, the
"	    script processing continues at the next line (unless the error was
"	    in a :return command).  On an error inside a function with the
"	    "abort" attribute, the function is aborted and the script processing
"	    continues after the function call; the value -1 is returned then.
"-------------------------------------------------------------------------------

XpathINIT

function! T8_F()
    if 1
	Xpath 'a'
	while 1
	    Xpath 'b'
	    asdf
	    Xpath 'c'
	    asdf | Xpath 'd'
	    Xpath 'e'
	    break
	endwhile
	Xpath 'f'
    endif | Xpath 'g'
    Xpath 'h'

    while 1
	Xpath 'i'
	if 1
	    Xpath 'j'
	    asdf
	    Xpath 'k'
	    asdf | Xpath 'l'
	    Xpath 'm'
	endif
	Xpath 'n'
	break
    endwhile | Xpath 'o'
    Xpath 'p'

    return novar		" returns (default return value 0)
    Xpath 'q'
    return 1			" not reached
endfunction

function! T8_G() abort
    if 1
	Xpath 'r'
	while 1
	    Xpath 's'
	    asdf		" returns -1
	    Xpath 't'
	    break
	endwhile
	Xpath 'v'
    endif | Xpath 'w'
    Xpath 'x'

    return -4			" not reached
endfunction

function! T8_H() abort
    while 1
	Xpath 'A'
	if 1
	    Xpath 'B'
	    asdf		" returns -1
	    Xpath 'C'
	endif
	Xpath 'D'
	break
    endwhile | Xpath 'E'
    Xpath 'F'

    return -4			" not reached
endfunction

" Aborted functions (T8_G and T8_H) return -1.
let g:test8_sum = (T8_F() + 1) - 4 * T8_G() - 8 * T8_H()
Xpath 'X'
let g:test8_result = g:Xpath

func Test_error_in_function()
    call assert_equal(13, g:test8_sum)
    call assert_equal('abcefghijkmnoprsABX', g:test8_result)

    delfunction T8_F
    delfunction T8_G
    delfunction T8_H
endfunc


"-------------------------------------------------------------------------------
" Test 9:   Continuing after aborted functions				    {{{1
"
"	    When a function with the "abort" attribute is aborted due to an
"	    error, the next function back in the call hierarchy without an
"	    "abort" attribute continues; the value -1 is returned then.
"-------------------------------------------------------------------------------

XpathINIT

function! F() abort
    Xpath 'a'
    let result = G()	" not aborted
    Xpath 'b'
    if result != 2
	Xpath 'c'
    endif
    return 1
endfunction

function! G()		" no abort attribute
    Xpath 'd'
    if H() != -1	" aborted
	Xpath 'e'
    endif
    Xpath 'f'
    return 2
endfunction

function! H() abort
    Xpath 'g'
    call I()		" aborted
    Xpath 'h'
    return 4
endfunction

function! I() abort
    Xpath 'i'
    asdf		" error
    Xpath 'j'
    return 8
endfunction

if F() != 1
    Xpath 'k'
endif

let g:test9_result = g:Xpath

delfunction F
delfunction G
delfunction H
delfunction I

func Test_func_abort()
    call assert_equal('adgifb', g:test9_result)
endfunc


"-------------------------------------------------------------------------------
" Test 10:  :if, :elseif, :while argument parsing			    {{{1
"
"	    A '"' or '|' in an argument expression must not be mixed up with
"	    a comment or a next command after a bar.  Parsing errors should
"	    be recognized.
"-------------------------------------------------------------------------------

XpathINIT

function! MSG(enr, emsg)
    let english = v:lang == "C" || v:lang =~ '^[Ee]n'
    if a:enr == ""
	Xout "TODO: Add message number for:" a:emsg
	let v:errmsg = ":" . v:errmsg
    endif
    let match = 1
    if v:errmsg !~ '^'.a:enr.':' || (english && v:errmsg !~ a:emsg)
	let match = 0
	if v:errmsg == ""
	    Xout "Message missing."
	else
	    let v:errmsg = v:errmsg->escape('"')
	    Xout "Unexpected message:" v:errmsg
	endif
    endif
    return match
endfunc

if 1 || strlen("\"") | Xpath 'a'
    Xpath 'b'
endif
Xpath 'c'

if 0
elseif 1 || strlen("\"") | Xpath 'd'
    Xpath 'e'
endif
Xpath 'f'

while 1 || strlen("\"") | Xpath 'g'
    Xpath 'h'
    break
endwhile
Xpath 'i'

let v:errmsg = ""
if 1 ||| strlen("\"") | Xpath 'j'
    Xpath 'k'
endif
Xpath 'l'
if !MSG('E15', "Invalid expression")
    Xpath 'm'
endif

let v:errmsg = ""
if 0
elseif 1 ||| strlen("\"") | Xpath 'n'
    Xpath 'o'
endif
Xpath 'p'
if !MSG('E15', "Invalid expression")
    Xpath 'q'
endif

let v:errmsg = ""
while 1 ||| strlen("\"") | Xpath 'r'
    Xpath 's'
    break
endwhile
Xpath 't'
if !MSG('E15', "Invalid expression")
    Xpath 'u'
endif

let g:test10_result = g:Xpath
delfunction MSG

func Test_expr_parsing()
    call assert_equal('abcdefghilpt', g:test10_result)
endfunc


"-------------------------------------------------------------------------------
" Test 11:  :if, :elseif, :while argument evaluation after abort	    {{{1
"
"	    When code is skipped over due to an error, the boolean argument to
"	    an :if, :elseif, or :while must not be evaluated.
"-------------------------------------------------------------------------------

XpathINIT

let calls = 0

function! P(num)
    let g:calls = g:calls + a:num   " side effect on call
    return 0
endfunction

if 1
    Xpath 'a'
    asdf		" error
    Xpath 'b'
    if P(1)		" should not be called
	Xpath 'c'
    elseif !P(2)	" should not be called
	Xpath 'd'
    else
	Xpath 'e'
    endif
    Xpath 'f'
    while P(4)		" should not be called
	Xpath 'g'
    endwhile
    Xpath 'h'
endif
Xpath 'x'

let g:test11_calls = calls
let g:test11_result = g:Xpath

unlet calls
delfunction P

func Test_arg_abort()
    call assert_equal(0, g:test11_calls)
    call assert_equal('ax', g:test11_result)
endfunc


"-------------------------------------------------------------------------------
" Test 12:  Expressions in braces in skipped code			    {{{1
"
"	    In code skipped over due to an error or inactive conditional,
"	    an expression in braces as part of a variable or function name
"	    should not be evaluated.
"-------------------------------------------------------------------------------

XpathINIT

func NULL()
    Xpath 'a'
    return 0
endfunc

func ZERO()
    Xpath 'b'
    return 0
endfunc

func! F0()
    Xpath 'c'
endfunc

func! F1(arg)
    Xpath 'e'
endfunc

let V0 = 1

Xpath 'f'
echo 0 ? F{NULL() + V{ZERO()}}() : 1

Xpath 'g'
if 0
    Xpath 'h'
    call F{NULL() + V{ZERO()}}()
endif

Xpath 'i'
if 1
    asdf		" error
    Xpath 'j'
    call F1(F{NULL() + V{ZERO()}}())
endif

Xpath 'k'
if 1
    asdf		" error
    Xpath 'l'
    call F{NULL() + V{ZERO()}}()
endif

let g:test12_result = g:Xpath

func Test_braces_skipped()
    call assert_equal('fgik', g:test12_result)
endfunc


"-------------------------------------------------------------------------------
" Test 13:  Failure in argument evaluation for :while			    {{{1
"
"	    A failure in the expression evaluation for the condition of a :while
"	    causes the whole :while loop until the matching :endwhile being
"	    ignored.  Continuation is at the next following line.
"-------------------------------------------------------------------------------

XpathINIT

Xpath 'a'
while asdf
    Xpath 'b'
    while 1
	Xpath 'c'
	break
    endwhile
    Xpath 'd'
    break
endwhile
Xpath 'e'

while asdf | Xpath 'f' | endwhile | Xpath 'g'
Xpath 'h'
let g:test13_result = g:Xpath

func Test_while_fail()
    call assert_equal('aeh', g:test13_result)
endfunc


"-------------------------------------------------------------------------------
" Test 14:  Failure in argument evaluation for :if			    {{{1
"
"	    A failure in the expression evaluation for the condition of an :if
"	    does not cause the corresponding :else or :endif being matched to
"	    a previous :if/:elseif.  Neither of both branches of the failed :if
"	    are executed.
"-------------------------------------------------------------------------------

XpathINIT

function! F()
    Xpath 'a'
    let x = 0
    if x		" false
	Xpath 'b'
    elseif !x		" always true
	Xpath 'c'
	let x = 1
	if g:boolvar	" possibly undefined
	    Xpath 'd'
	else
	    Xpath 'e'
	endif
	Xpath 'f'
    elseif x		" never executed
	Xpath 'g'
    endif
    Xpath 'h'
endfunction

let boolvar = 1
call F()
Xpath '-'

unlet boolvar
call F()
let g:test14_result = g:Xpath

delfunction F

func Test_if_fail()
    call assert_equal('acdfh-acfh', g:test14_result)
endfunc


"-------------------------------------------------------------------------------
" Test 15:  Failure in argument evaluation for :if (bar)		    {{{1
"
"	    Like previous test, except that the failing :if ... | ... | :endif
"	    is in a single line.
"-------------------------------------------------------------------------------

XpathINIT

function! F()
    Xpath 'a'
    let x = 0
    if x		" false
	Xpath 'b'
    elseif !x		" always true
	Xpath 'c'
	let x = 1
	if g:boolvar | Xpath 'd' | else | Xpath 'e' | endif
	Xpath 'f'
    elseif x		" never executed
	Xpath 'g'
    endif
    Xpath 'h'
endfunction

let boolvar = 1
call F()
Xpath '-'

unlet boolvar
call F()
let g:test15_result = g:Xpath

delfunction F

func Test_if_bar_fail()
    call assert_equal('acdfh-acfh', g:test15_result)
endfunc

"-------------------------------------------------------------------------------
" Test 16:  Double :else or :elseif after :else				    {{{1
"
"	    Multiple :elses or an :elseif after an :else are forbidden.
"-------------------------------------------------------------------------------

func T16_F() abort
  if 0
    Xpath 'a'
  else
    Xpath 'b'
  else		" aborts function
    Xpath 'c'
  endif
  Xpath 'd'
endfunc

func T16_G() abort
  if 0
    Xpath 'a'
  else
    Xpath 'b'
  elseif 1		" aborts function
    Xpath 'c'
  else
    Xpath 'd'
  endif
  Xpath 'e'
endfunc

func T16_H() abort
  if 0
    Xpath 'a'
  elseif 0
    Xpath 'b'
  else
    Xpath 'c'
  else		" aborts function
    Xpath 'd'
  endif
  Xpath 'e'
endfunc

func T16_I() abort
  if 0
    Xpath 'a'
  elseif 0
    Xpath 'b'
  else
    Xpath 'c'
  elseif 1		" aborts function
    Xpath 'd'
  else
    Xpath 'e'
  endif
  Xpath 'f'
endfunc

func Test_Multi_Else()
  XpathINIT
  try
    call T16_F()
  catch /E583:/
    Xpath 'e'
  endtry
  call assert_equal('be', g:Xpath)

  XpathINIT
  try
    call T16_G()
  catch /E584:/
    Xpath 'f'
  endtry
  call assert_equal('bf', g:Xpath)

  XpathINIT
  try
    call T16_H()
  catch /E583:/
    Xpath 'f'
  endtry
  call assert_equal('cf', g:Xpath)

  XpathINIT
  try
    call T16_I()
  catch /E584:/
    Xpath 'g'
  endtry
  call assert_equal('cg', g:Xpath)
endfunc

"-------------------------------------------------------------------------------
" Test 17:  Nesting of unmatched :if or :endif inside a :while		    {{{1
"
"	    The :while/:endwhile takes precedence in nesting over an unclosed
"	    :if or an unopened :endif.
"-------------------------------------------------------------------------------

" While loops inside a function are continued on error.
func T17_F()
  let loops = 3
  while loops > 0
    let loops -= 1
    Xpath 'a' . loops
    if (loops == 1)
      Xpath 'b' . loops
      continue
    elseif (loops == 0)
      Xpath 'c' . loops
      break
    elseif 1
      Xpath 'd' . loops
    " endif missing!
  endwhile	" :endwhile after :if 1
  Xpath 'e'
endfunc

func T17_G()
  let loops = 2
  while loops > 0
    let loops -= 1
    Xpath 'a' . loops
    if 0
      Xpath 'b' . loops
    " endif missing
  endwhile	" :endwhile after :if 0
endfunc

func T17_H()
  let loops = 2
  while loops > 0
    let loops -= 1
    Xpath 'a' . loops
    " if missing!
    endif	" :endif without :if in while
    Xpath 'b' . loops
  endwhile
endfunc

" Error continuation outside a function is at the outermost :endwhile or :endif.
XpathINIT
let v:errmsg = ''
let loops = 2
while loops > 0
    let loops -= 1
    Xpath 'a' . loops
    if 0
	Xpath 'b' . loops
    " endif missing! Following :endwhile fails.
endwhile | Xpath 'c'
Xpath 'd'
call assert_match('E171:', v:errmsg)
call assert_equal('a1d', g:Xpath)

func Test_unmatched_if_in_while()
  XpathINIT
  call assert_fails('call T17_F()', 'E171:')
  call assert_equal('a2d2a1b1a0c0e', g:Xpath)

  XpathINIT
  call assert_fails('call T17_G()', 'E171:')
  call assert_equal('a1a0', g:Xpath)

  XpathINIT
  call assert_fails('call T17_H()', 'E580:')
  call assert_equal('a1b1a0b0', g:Xpath)
endfunc

"-------------------------------------------------------------------------------
"-------------------------------------------------------------------------------
"-------------------------------------------------------------------------------
" Test 87   using (expr) ? funcref : funcref				    {{{1
"
"	    Vim needs to correctly parse the funcref and even when it does
"	    not execute the funcref, it needs to consume the trailing ()
"-------------------------------------------------------------------------------

func Add2(x1, x2)
  return a:x1 + a:x2
endfu

func GetStr()
  return "abcdefghijklmnopqrstuvwxyp"
endfu

func Test_funcref_with_condexpr()
  call assert_equal(5, function('Add2')(2,3))

  call assert_equal(3, 1 ? function('Add2')(1,2) : function('Add2')(2,3))
  call assert_equal(5, 0 ? function('Add2')(1,2) : function('Add2')(2,3))
  " Make sure, GetStr() still works.
  call assert_equal('abcdefghijk', GetStr()[0:10])
endfunc

"-------------------------------------------------------------------------------
" Test 90:  Recognizing {} in variable name.			    {{{1
"-------------------------------------------------------------------------------

func Test_curlies()
    let s:var = 66
    let ns = 's'
    call assert_equal(66, {ns}:var)

    let g:a = {}
    let g:b = 't'
    let g:a[g:b] = 77
    call assert_equal(77, g:a['t'])
endfunc

"-------------------------------------------------------------------------------
" Test 91:  using type().					    {{{1
"-------------------------------------------------------------------------------

func Test_type()
    call assert_equal(0, type(0))
    call assert_equal(1, type(""))
    call assert_equal(2, type(function("tr")))
    call assert_equal(2, type(function("tr", [8])))
    call assert_equal(3, type([]))
    call assert_equal(4, type({}))
    call assert_equal(5, type(0.0))
    call assert_equal(6, type(v:false))
    call assert_equal(6, type(v:true))
    call assert_equal(7, type(v:null))
    call assert_equal(v:t_number, type(0))
    call assert_equal(v:t_string, type(""))
    call assert_equal(v:t_func, type(function("tr")))
    call assert_equal(v:t_list, type([]))
    call assert_equal(v:t_dict, type({}))
    call assert_equal(v:t_float, type(0.0))
    call assert_equal(v:t_bool, type(v:false))
    call assert_equal(v:t_bool, type(v:true))
    call assert_equal(v:t_string, type(v:_null_string))
    call assert_equal(v:t_list, type(v:_null_list))
    call assert_equal(v:t_dict, type(v:_null_dict))
    call assert_equal(v:t_blob, type(v:_null_blob))

    call assert_equal(0, 0 + v:false)
    call assert_equal(1, 0 + v:true)
    " call assert_equal(0, 0 + v:none)
    call assert_equal(0, 0 + v:null)

    call assert_equal('v:false', '' . v:false)
    call assert_equal('v:true', '' . v:true)
    " call assert_equal('v:none', '' . v:none)
    call assert_equal('v:null', '' . v:null)

    call assert_true(v:false == 0)
    call assert_false(v:false != 0)
    call assert_true(v:true == 1)
    call assert_false(v:true != 1)
    call assert_false(v:true == v:false)
    call assert_true(v:true != v:false)

    call assert_true(v:null == 0)
    call assert_false(v:null != 0)
    " call assert_true(v:none == 0)
    " call assert_false(v:none != 0)

    call assert_true(v:false is v:false)
    call assert_true(v:true is v:true)
    " call assert_true(v:none is v:none)
    call assert_true(v:null is v:null)

    call assert_false(v:false isnot v:false)
    call assert_false(v:true isnot v:true)
    " call assert_false(v:none isnot v:none)
    call assert_false(v:null isnot v:null)

    call assert_false(v:false is 0)
    call assert_false(v:true is 1)
    call assert_false(v:true is v:false)
    " call assert_false(v:none is 0)
    call assert_false(v:null is 0)
    " call assert_false(v:null is v:none)

    call assert_true(v:false isnot 0)
    call assert_true(v:true isnot 1)
    call assert_true(v:true isnot v:false)
    " call assert_true(v:none isnot 0)
    call assert_true(v:null isnot 0)
    " call assert_true(v:null isnot v:none)

    call assert_equal(v:false, eval(string(v:false)))
    call assert_equal(v:true, eval(string(v:true)))
    " call assert_equal(v:none, eval(string(v:none)))
    call assert_equal(v:null, eval(string(v:null)))

    call assert_equal(v:false, copy(v:false))
    call assert_equal(v:true, copy(v:true))
    " call assert_equal(v:none, copy(v:none))
    call assert_equal(v:null, copy(v:null))

    call assert_equal([v:false], deepcopy([v:false]))
    call assert_equal([v:true], deepcopy([v:true]))
    " call assert_equal([v:none], deepcopy([v:none]))
    call assert_equal([v:null], deepcopy([v:null]))

    call assert_true(empty(v:false))
    call assert_false(empty(v:true))
    call assert_true(empty(v:null))
    " call assert_true(empty(v:none))

    func ChangeYourMind()
	try
	    return v:true
	finally
	    return 'something else'
	endtry
    endfunc

    call ChangeYourMind()
endfunc

"-------------------------------------------------------------------------------
" Test 92:  skipping code                       {{{1
"-------------------------------------------------------------------------------

func Test_skip()
    let Fn = function('Test_type')
    call assert_false(0 && Fn[1])
    call assert_false(0 && string(Fn))
    call assert_false(0 && len(Fn))
    let l = []
    call assert_false(0 && l[1])
    call assert_false(0 && string(l))
    call assert_false(0 && len(l))
    let f = 1.0
    call assert_false(0 && f[1])
    call assert_false(0 && string(f))
    call assert_false(0 && len(f))
    let sp = v:null
    call assert_false(0 && sp[1])
    call assert_false(0 && string(sp))
    call assert_false(0 && len(sp))

endfunc

"-------------------------------------------------------------------------------
" Test 93:  :echo and string()					    {{{1
"-------------------------------------------------------------------------------

func Test_echo_and_string()
    " String
    let a = 'foo bar'
    redir => result
    echo a
    echo string(a)
    redir END
    let l = split(result, "\n")
    call assert_equal(["foo bar",
		     \ "'foo bar'"], l)

    " Float
    if has('float')
	let a = -1.2e0
	redir => result
	echo a
	echo string(a)
	redir END
	let l = split(result, "\n")
	call assert_equal(["-1.2",
			 \ "-1.2"], l)
    endif

    " Funcref
    redir => result
    echo function('string')
    echo string(function('string'))
    redir END
    let l = split(result, "\n")
    call assert_equal(["string",
		     \ "function('string')"], l)

    " Empty dictionaries in a list
    let a = {}
    redir => result
    echo [a, a, a]
    echo string([a, a, a])
    redir END
    let l = split(result, "\n")
    call assert_equal(["[{}, {}, {}]",
		     \ "[{}, {}, {}]"], l)

    " Empty dictionaries in a dictionary
    let a = {}
    let b = {"a": a, "b": a}
    redir => result
    echo b
    echo string(b)
    redir END
    let l = split(result, "\n")
    call assert_equal(["{'a': {}, 'b': {}}",
		     \ "{'a': {}, 'b': {}}"], l)

    " Empty lists in a list
    let a = []
    redir => result
    echo [a, a, a]
    echo string([a, a, a])
    redir END
    let l = split(result, "\n")
    call assert_equal(["[[], [], []]",
		     \ "[[], [], []]"], l)

    " Empty lists in a dictionary
    let a = []
    let b = {"a": a, "b": a}
    redir => result
    echo b
    echo string(b)
    redir END
    let l = split(result, "\n")
    call assert_equal(["{'a': [], 'b': []}",
		     \ "{'a': [], 'b': []}"], l)
endfunc

"-------------------------------------------------------------------------------
" Test 94:  64-bit Numbers					    {{{1
"-------------------------------------------------------------------------------

func Test_num64()
    call assert_notequal( 4294967296, 0)
    call assert_notequal(-4294967296, 0)
    call assert_equal( 4294967296,  0xFFFFffff + 1)
    call assert_equal(-4294967296, -0xFFFFffff - 1)

    call assert_equal( 9223372036854775807,  1 / 0)
    call assert_equal(-9223372036854775807, -1 / 0)
    call assert_equal(-9223372036854775807 - 1,  0 / 0)

    if has('float')
      call assert_equal( 0x7FFFffffFFFFffff, float2nr( 1.0e150))
      call assert_equal(-0x7FFFffffFFFFffff, float2nr(-1.0e150))
    endif

    let rng = range(0xFFFFffff, 0x100000001)
    call assert_equal([0xFFFFffff, 0x100000000, 0x100000001], rng)
    call assert_equal(0x100000001, max(rng))
    call assert_equal(0xFFFFffff, min(rng))
    call assert_equal(rng, sort(range(0x100000001, 0xFFFFffff, -1), 'N'))
endfunc

"-------------------------------------------------------------------------------
" Test 95:  lines of :append, :change, :insert			    {{{1
"-------------------------------------------------------------------------------

func DefineFunction(name, body)
    let func = join(['function! ' . a:name . '()'] + a:body + ['endfunction'], "\n")
    exec func
endfunc

func Test_script_lines()
    " :append
    try
	call DefineFunction('T_Append', [
		    \ 'append',
		    \ 'py <<EOS',
		    \ '.',
		    \ ])
    catch
	call assert_report("Can't define function")
    endtry
    try
	call DefineFunction('T_Append', [
		    \ 'append',
		    \ 'abc',
		    \ ])
	call assert_report("Shouldn't be able to define function")
    catch
	call assert_exception('Vim(function):E126: Missing :endfunction')
    endtry

    " :change
    try
	call DefineFunction('T_Change', [
		    \ 'change',
		    \ 'py <<EOS',
		    \ '.',
		    \ ])
    catch
	call assert_report("Can't define function")
    endtry
    try
	call DefineFunction('T_Change', [
		    \ 'change',
		    \ 'abc',
		    \ ])
	call assert_report("Shouldn't be able to define function")
    catch
	call assert_exception('Vim(function):E126: Missing :endfunction')
    endtry

    " :insert
    try
	call DefineFunction('T_Insert', [
		    \ 'insert',
		    \ 'py <<EOS',
		    \ '.',
		    \ ])
    catch
	call assert_report("Can't define function")
    endtry
    try
	call DefineFunction('T_Insert', [
		    \ 'insert',
		    \ 'abc',
		    \ ])
	call assert_report("Shouldn't be able to define function")
    catch
	call assert_exception('Vim(function):E126: Missing :endfunction')
    endtry
endfunc

"-------------------------------------------------------------------------------
" Test 96:  line continuation						    {{{1
"
"	    Undefined behavior was detected by ubsan with line continuation
"	    after an empty line.
"-------------------------------------------------------------------------------
func Test_script_empty_line_continuation()

    \
endfunc

"-------------------------------------------------------------------------------
" Test 97:  bitwise functions						    {{{1
"-------------------------------------------------------------------------------
func Test_bitwise_functions()
    " and
    call assert_equal(127, and(127, 127))
    call assert_equal(16, and(127, 16))
    eval 127->and(16)->assert_equal(16)
    call assert_equal(0, and(127, 128))
    call assert_fails("call and(1.0, 1)", 'E805:')
    call assert_fails("call and([], 1)", 'E745:')
    call assert_fails("call and({}, 1)", 'E728:')
    call assert_fails("call and(1, 1.0)", 'E805:')
    call assert_fails("call and(1, [])", 'E745:')
    call assert_fails("call and(1, {})", 'E728:')
    " or
    call assert_equal(23, or(16, 7))
    call assert_equal(15, or(8, 7))
    eval 8->or(7)->assert_equal(15)
    call assert_equal(123, or(0, 123))
    call assert_fails("call or(1.0, 1)", 'E805:')
    call assert_fails("call or([], 1)", 'E745:')
    call assert_fails("call or({}, 1)", 'E728:')
    call assert_fails("call or(1, 1.0)", 'E805:')
    call assert_fails("call or(1, [])", 'E745:')
    call assert_fails("call or(1, {})", 'E728:')
    " xor
    call assert_equal(0, xor(127, 127))
    call assert_equal(111, xor(127, 16))
    eval 127->xor(16)->assert_equal(111)
    call assert_equal(255, xor(127, 128))
    call assert_fails("call xor(1.0, 1)", 'E805:')
    call assert_fails("call xor([], 1)", 'E745:')
    call assert_fails("call xor({}, 1)", 'E728:')
    call assert_fails("call xor(1, 1.0)", 'E805:')
    call assert_fails("call xor(1, [])", 'E745:')
    call assert_fails("call xor(1, {})", 'E728:')
    " invert
    call assert_equal(65408, and(invert(127), 65535))
    eval 127->invert()->and(65535)->assert_equal(65408)
    call assert_equal(65519, and(invert(16), 65535))
    call assert_equal(65407, and(invert(128), 65535))
    call assert_fails("call invert(1.0)", 'E805:')
    call assert_fails("call invert([])", 'E745:')
    call assert_fails("call invert({})", 'E728:')
endfunc

" Test using bang after user command				    {{{1
func Test_user_command_with_bang()
    command -bang Nieuw let nieuw = 1
    Ni!
    call assert_equal(1, nieuw)
    unlet nieuw
    delcommand Nieuw
endfunc

func Test_script_expand_sfile()
  let lines =<< trim END
    func s:snr()
      return expand('<sfile>')
    endfunc
    let g:result = s:snr()
  END
  call writefile(lines, 'Xexpand')
  source Xexpand
  call assert_match('<SNR>\d\+_snr', g:result)
  source Xexpand
  call assert_match('<SNR>\d\+_snr', g:result)

  call delete('Xexpand')
  unlet g:result
endfunc

func Test_compound_assignment_operators()
    " Test for number
    let x = 1
    let x += 10
    call assert_equal(11, x)
    let x -= 5
    call assert_equal(6, x)
    let x *= 4
    call assert_equal(24, x)
    let x /= 3
    call assert_equal(8, x)
    let x %= 3
    call assert_equal(2, x)
    let x .= 'n'
    call assert_equal('2n', x)

    " Test special cases: division or modulus with 0.
    let x = 1
    let x /= 0
    call assert_equal(0x7FFFFFFFFFFFFFFF, x)

    let x = -1
    let x /= 0
    call assert_equal(-0x7FFFFFFFFFFFFFFF, x)

    let x = 0
    let x /= 0
    call assert_equal(-0x7FFFFFFFFFFFFFFF - 1, x)

    let x = 1
    let x %= 0
    call assert_equal(0, x)

    let x = -1
    let x %= 0
    call assert_equal(0, x)

    let x = 0
    let x %= 0
    call assert_equal(0, x)

    " Test for string
    let x = 'str'
    let x .= 'ing'
    call assert_equal('string', x)
    let x += 1
    call assert_equal(1, x)

    if has('float')
      " Test for float
      let x -= 1.5
      call assert_equal(-0.5, x)
      let x = 0.5
      let x += 4.5
      call assert_equal(5.0, x)
      let x -= 1.5
      call assert_equal(3.5, x)
      let x *= 3.0
      call assert_equal(10.5, x)
      let x /= 2.5
      call assert_equal(4.2, x)
      call assert_fails('let x %= 0.5', 'E734')
      call assert_fails('let x .= "f"', 'E734')
      let x = !3.14
      call assert_equal(0.0, x)

      " integer and float operations
      let x = 1
      let x *= 2.1
      call assert_equal(2.1, x)
      let x = 1
      let x /= 0.25
      call assert_equal(4.0, x)
      let x = 1
      call assert_fails('let x %= 0.25', 'E734:')
      let x = 1
      call assert_fails('let x .= 0.25', 'E734:')
      let x = 1.0
      call assert_fails('let x += [1.1]', 'E734:')
    endif

    " Test for environment variable
    let $FOO = 1
    call assert_fails('let $FOO += 1', 'E734')
    call assert_fails('let $FOO -= 1', 'E734')
    call assert_fails('let $FOO *= 1', 'E734')
    call assert_fails('let $FOO /= 1', 'E734')
    call assert_fails('let $FOO %= 1', 'E734')
    let $FOO .= 's'
    call assert_equal('1s', $FOO)
    unlet $FOO

    " Test for option variable (type: number)
    let &scrolljump = 1
    let &scrolljump += 5
    call assert_equal(6, &scrolljump)
    let &scrolljump -= 2
    call assert_equal(4, &scrolljump)
    let &scrolljump *= 3
    call assert_equal(12, &scrolljump)
    let &scrolljump /= 2
    call assert_equal(6, &scrolljump)
    let &scrolljump %= 5
    call assert_equal(1, &scrolljump)
    call assert_fails('let &scrolljump .= "j"', 'E734:')
    set scrolljump&vim

    let &foldlevelstart = 2
    let &foldlevelstart -= 1
    call assert_equal(1, &foldlevelstart)
    let &foldlevelstart -= 1
    call assert_equal(0, &foldlevelstart)
    let &foldlevelstart = 2
    let &foldlevelstart -= 2
    call assert_equal(0, &foldlevelstart)

    " Test for register
    let @/ = 1
    call assert_fails('let @/ += 1', 'E734:')
    call assert_fails('let @/ -= 1', 'E734:')
    call assert_fails('let @/ *= 1', 'E734:')
    call assert_fails('let @/ /= 1', 'E734:')
    call assert_fails('let @/ %= 1', 'E734:')
    let @/ .= 's'
    call assert_equal('1s', @/)
    let @/ = ''
endfunc

func Test_unlet_env()
    let $TESTVAR = 'yes'
    call assert_equal('yes', $TESTVAR)
    call assert_fails('lockvar $TESTVAR', 'E940')
    call assert_fails('unlockvar $TESTVAR', 'E940')
    call assert_equal('yes', $TESTVAR)
    if 0
        unlet $TESTVAR
    endif
    call assert_equal('yes', $TESTVAR)
    unlet $TESTVAR
    call assert_equal('', $TESTVAR)
endfunc

" Test for missing :endif, :endfor, :endwhile and :endtry           {{{1
func Test_missing_end()
  call writefile(['if 2 > 1', 'echo ">"'], 'Xscript')
  call assert_fails('source Xscript', 'E171:')
  call writefile(['for i in range(5)', 'echo i'], 'Xscript')
  call assert_fails('source Xscript', 'E170:')
  call writefile(['while v:true', 'echo "."'], 'Xscript')
  call assert_fails('source Xscript', 'E170:')
  call writefile(['try', 'echo "."'], 'Xscript')
  call assert_fails('source Xscript', 'E600:')
  call delete('Xscript')

  " Using endfor with :while
  let caught_e732 = 0
  try
    while v:true
    endfor
  catch /E732:/
    let caught_e732 = 1
  endtry
  call assert_equal(1, caught_e732)

  " Using endwhile with :for
  let caught_e733 = 0
  try
    for i in range(1)
    endwhile
  catch /E733:/
    let caught_e733 = 1
  endtry
  call assert_equal(1, caught_e733)

  " Using endfunc with :if
  call assert_fails('exe "if 1 | endfunc | endif"', 'E193:')

  " Missing 'in' in a :for statement
  call assert_fails('for i range(1) | endfor', 'E690:')

  " Incorrect number of variables in for
  call assert_fails('for [i,] in range(3) | endfor', 'E475:')
endfunc

" Test for deep nesting of if/for/while/try statements              {{{1
func Test_deep_nest()
  if !CanRunVimInTerminal()
    throw 'Skipped: cannot run vim in terminal'
  endif

  let lines =<< trim [SCRIPT]
    " Deep nesting of if ... endif
    func Test1()
      let @a = join(repeat(['if v:true'], 51), "\n")
      let @a ..= "\n"
      let @a ..= join(repeat(['endif'], 51), "\n")
      @a
      let @a = ''
    endfunc

    " Deep nesting of for ... endfor
    func Test2()
      let @a = join(repeat(['for i in [1]'], 51), "\n")
      let @a ..= "\n"
      let @a ..= join(repeat(['endfor'], 51), "\n")
      @a
      let @a = ''
    endfunc

    " Deep nesting of while ... endwhile
    func Test3()
      let @a = join(repeat(['while v:true'], 51), "\n")
      let @a ..= "\n"
      let @a ..= join(repeat(['endwhile'], 51), "\n")
      @a
      let @a = ''
    endfunc

    " Deep nesting of try ... endtry
    func Test4()
      let @a = join(repeat(['try'], 51), "\n")
      let @a ..= "\necho v:true\n"
      let @a ..= join(repeat(['endtry'], 51), "\n")
      @a
      let @a = ''
    endfunc

    " Deep nesting of function ... endfunction
    func Test5()
      let @a = join(repeat(['function X()'], 51), "\n")
      let @a ..= "\necho v:true\n"
      let @a ..= join(repeat(['endfunction'], 51), "\n")
      @a
      let @a = ''
    endfunc
  [SCRIPT]
  call writefile(lines, 'Xscript')

  let buf = RunVimInTerminal('-S Xscript', {'rows': 6})

  " Deep nesting of if ... endif
  call term_sendkeys(buf, ":call Test1()\n")
  call term_wait(buf)
  call WaitForAssert({-> assert_match('^E579:', term_getline(buf, 5))})

  " Deep nesting of for ... endfor
  call term_sendkeys(buf, ":call Test2()\n")
  call term_wait(buf)
  call WaitForAssert({-> assert_match('^E585:', term_getline(buf, 5))})

  " Deep nesting of while ... endwhile
  call term_sendkeys(buf, ":call Test3()\n")
  call term_wait(buf)
  call WaitForAssert({-> assert_match('^E585:', term_getline(buf, 5))})

  " Deep nesting of try ... endtry
  call term_sendkeys(buf, ":call Test4()\n")
  call term_wait(buf)
  call WaitForAssert({-> assert_match('^E601:', term_getline(buf, 5))})

  " Deep nesting of function ... endfunction
  call term_sendkeys(buf, ":call Test5()\n")
  call term_wait(buf)
  call WaitForAssert({-> assert_match('^E1058:', term_getline(buf, 4))})
  call term_sendkeys(buf, "\<C-C>\n")
  call term_wait(buf)

  "let l = ''
  "for i in range(1, 6)
  "  let l ..= term_getline(buf, i) . "\n"
  "endfor
  "call assert_report(l)

  call StopVimInTerminal(buf)
  call delete('Xscript')
endfunc

" Test for errors in converting to float from various types         {{{1
func Test_float_conversion_errors()
  if has('float')
    call assert_fails('let x = 4.0 % 2.0', 'E804')
    call assert_fails('echo 1.1[0]', 'E806')
    call assert_fails('echo sort([function("min"), 1], "f")', 'E891:')
    call assert_fails('echo 3.2 == "vim"', 'E892:')
    call assert_fails('echo sort([[], 1], "f")', 'E893:')
    call assert_fails('echo sort([{}, 1], "f")', 'E894:')
    call assert_fails('echo 3.2 == v:true', 'E362:')
    " call assert_fails('echo 3.2 == v:none', 'E907:')
  endif
endfunc

func Test_invalid_function_names()
  " function name not starting with capital
  let caught_e128 = 0
  try
    func! g:test()
      echo "test"
    endfunc
  catch /E128:/
    let caught_e128 = 1
  endtry
  call assert_equal(1, caught_e128)

  " function name includes a colon
  let caught_e884 = 0
  try
    func! b:test()
      echo "test"
    endfunc
  catch /E884:/
    let caught_e884 = 1
  endtry
  call assert_equal(1, caught_e884)

  " function name folowed by #
  let caught_e128 = 0
  try
    func! test2() "#
      echo "test2"
    endfunc
  catch /E128:/
    let caught_e128 = 1
  endtry
  call assert_equal(1, caught_e128)

  " function name starting with/without "g:", buffer-local funcref.
  function! g:Foo(n)
    return 'called Foo(' . a:n . ')'
  endfunction
  let b:my_func = function('Foo')
  call assert_equal('called Foo(1)', b:my_func(1))
  call assert_equal('called Foo(2)', g:Foo(2))
  call assert_equal('called Foo(3)', Foo(3))
  delfunc g:Foo

  " script-local function used in Funcref must exist.
  let lines =<< trim END
    func s:Testje()
      return "foo"
    endfunc
    let Bar = function('s:Testje')
    call assert_equal(0, exists('s:Testje'))
    call assert_equal(1, exists('*s:Testje'))
    call assert_equal(1, exists('Bar'))
    call assert_equal(1, exists('*Bar'))
  END
  call writefile(lines, 'Xscript')
  source Xscript
  call delete('Xscript')
endfunc

" substring and variable name
func Test_substring_var()
  let str = 'abcdef'
  let n = 3
  call assert_equal('def', str[n:])
  call assert_equal('abcd', str[:n])
  call assert_equal('d', str[n:n])
  unlet n
  let nn = 3
  call assert_equal('def', str[nn:])
  call assert_equal('abcd', str[:nn])
  call assert_equal('d', str[nn:nn])
  unlet nn
  let b:nn = 4
  call assert_equal('ef', str[b:nn:])
  call assert_equal('abcde', str[:b:nn])
  call assert_equal('e', str[b:nn:b:nn])
  unlet b:nn
endfunc

func Test_for_over_string()
  let res = ''
  for c in 'aéc̀d'
    let res ..= c .. '-'
  endfor
  call assert_equal('a-é-c̀-d-', res)

  let res = ''
  for c in ''
    let res ..= c .. '-'
  endfor
  call assert_equal('', res)

  let res = ''
  for c in v:_null_string
    let res ..= c .. '-'
  endfor
  call assert_equal('', res)
endfunc

"-------------------------------------------------------------------------------
" Modelines								    {{{1
" vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker
"-------------------------------------------------------------------------------