src/testdir/test_vim9_script.vim

" Test various aspects of the Vim9 script language.

source check.vim
source view_util.vim
source vim9.vim

def Test_syntax()
  let var = 234
  let other: list<string> = ['asdf']
enddef

let s:appendToMe = 'xxx'
let s:addToMe = 111
let g:existing = 'yes'
let g:inc_counter = 1
let $SOME_ENV_VAR = 'some'
let g:alist = [7]
let g:astring = 'text'

def Test_assignment()
  let bool1: bool = true
  assert_equal(v:true, bool1)
  let bool2: bool = false
  assert_equal(v:false, bool2)

  call CheckDefFailure(['let x:string'], 'E1069:')
  call CheckDefFailure(['let x:string = "x"'], 'E1069:')
  call CheckDefFailure(['let a:string = "x"'], 'E1069:')

  let a: number = 6
  assert_equal(6, a)

  if has('channel')
    let chan1: channel
    let job1: job
    let job2: job = job_start('willfail')
  endif
  if has('float')
    let float1: float = 3.4
  endif
  let Funky1: func
  let Funky2: func = function('len')
  let Party2: func = funcref('g:Test_syntax')

  g:newvar = 'new'
  assert_equal('new', g:newvar)

  assert_equal('yes', g:existing)
  g:existing = 'no'
  assert_equal('no', g:existing)

  v:char = 'abc'
  assert_equal('abc', v:char)

  $ENVVAR = 'foobar'
  assert_equal('foobar', $ENVVAR)
  $ENVVAR = ''

  s:appendToMe ..= 'yyy'
  assert_equal('xxxyyy', s:appendToMe)
  s:addToMe += 222
  assert_equal(333, s:addToMe)
  s:newVar = 'new'
  assert_equal('new', s:newVar)

  set ts=7
  &ts += 1
  assert_equal(8, &ts)
  &ts -= 3
  assert_equal(5, &ts)
  &ts *= 2
  assert_equal(10, &ts)
  &ts /= 3
  assert_equal(3, &ts)
  set ts=10
  &ts %= 4
  assert_equal(2, &ts)
  call CheckDefFailure(['&notex += 3'], 'E113:')
  call CheckDefFailure(['&ts ..= "xxx"'], 'E1019:')
  call CheckDefFailure(['&ts = [7]'], 'E1013:')
  call CheckDefExecFailure(['&ts = g:alist'], 'E1029: Expected number but got list')
  call CheckDefFailure(['&ts = "xx"'], 'E1013:')
  call CheckDefExecFailure(['&ts = g:astring'], 'E1029: Expected number but got string')
  call CheckDefFailure(['&path += 3'], 'E1013:')
  call CheckDefExecFailure(['&bs = "asdf"'], 'E474:')
  # test freeing ISN_STOREOPT
  call CheckDefFailure(['&ts = 3', 'let asdf'], 'E1022:')
  &ts = 8

  g:inc_counter += 1
  assert_equal(2, g:inc_counter)

  $SOME_ENV_VAR ..= 'more'
  assert_equal('somemore', $SOME_ENV_VAR)
  call CheckDefFailure(['$SOME_ENV_VAR += "more"'], 'E1013:')
  call CheckDefFailure(['$SOME_ENV_VAR += 123'], 'E1013:')

  @a = 'areg'
  @a ..= 'add'
  assert_equal('aregadd', @a)
  call CheckDefFailure(['@a += "more"'], 'E1013:')
  call CheckDefFailure(['@a += 123'], 'E1013:')

  v:errmsg = 'none'
  v:errmsg ..= 'again'
  assert_equal('noneagain', v:errmsg)
  call CheckDefFailure(['v:errmsg += "more"'], 'E1013:')
  call CheckDefFailure(['v:errmsg += 123'], 'E1013:')
enddef

def Test_assignment_list()
  let list1: list<bool> = [false, true, false]
  let list2: list<number> = [1, 2, 3]
  let list3: list<string> = ['sdf', 'asdf']
  let list4: list<any> = ['yes', true, 1234]
  let list5: list<blob> = [0z01, 0z02]

  let listS: list<string> = []
  let listN: list<number> = []

  assert_equal([1, 2, 3], list2)
  list2[-1] = 99
  assert_equal([1, 2, 99], list2)
  list2[-2] = 88
  assert_equal([1, 88, 99], list2)
  list2[-3] = 77
  assert_equal([77, 88, 99], list2)
  call CheckDefExecFailure(['let ll = [1, 2, 3]', 'll[-4] = 6'], 'E684:')

  # type becomes list<any>
  let somelist = rand() > 0 ? [1, 2, 3] : ['a', 'b', 'c']
enddef

def Test_assignment_dict()
  let dict1: dict<bool> = #{one: false, two: true}
  let dict2: dict<number> = #{one: 1, two: 2}
  let dict3: dict<string> = #{key: 'value'}
  let dict4: dict<any> = #{one: 1, two: '2'}
  let dict5: dict<blob> = #{one: 0z01, two: 0z02}

  call CheckDefExecFailure(['let dd = {}', 'dd[""] = 6'], 'E713:')

  # type becomes dict<any>
  let somedict = rand() > 0 ? #{a: 1, b: 2} : #{a: 'a', b: 'b'}
enddef

def Test_assignment_local()
  " Test in a separated file in order not to the current buffer/window/tab is
  " changed.
  let script_lines: list<string> =<< trim END
    let b:existing = 'yes'
    let w:existing = 'yes'
    let t:existing = 'yes'

    def Test_assignment_local_internal()
      b:newvar = 'new'
      assert_equal('new', b:newvar)
      assert_equal('yes', b:existing)
      b:existing = 'no'
      assert_equal('no', b:existing)
      b:existing ..= 'NO'
      assert_equal('noNO', b:existing)

      w:newvar = 'new'
      assert_equal('new', w:newvar)
      assert_equal('yes', w:existing)
      w:existing = 'no'
      assert_equal('no', w:existing)
      w:existing ..= 'NO'
      assert_equal('noNO', w:existing)

      t:newvar = 'new'
      assert_equal('new', t:newvar)
      assert_equal('yes', t:existing)
      t:existing = 'no'
      assert_equal('no', t:existing)
      t:existing ..= 'NO'
      assert_equal('noNO', t:existing)
    enddef
    call Test_assignment_local_internal()
  END
  call CheckScriptSuccess(script_lines)
enddef

def Test_assignment_default()

  # Test default values.
  let thebool: bool
  assert_equal(v:false, thebool)

  let thenumber: number
  assert_equal(0, thenumber)

  if has('float')
    let thefloat: float
    assert_equal(0.0, thefloat)
  endif

  let thestring: string
  assert_equal('', thestring)

  let theblob: blob
  assert_equal(0z, theblob)

  let Thefunc: func
  assert_equal(test_null_function(), Thefunc)

  let thelist: list<any>
  assert_equal([], thelist)

  let thedict: dict<any>
  assert_equal({}, thedict)

  if has('channel')
    let thejob: job
    assert_equal(test_null_job(), thejob)

    let thechannel: channel
    assert_equal(test_null_channel(), thechannel)
  endif

  let nr = 1234 | nr = 5678
  assert_equal(5678, nr)
enddef

def Mess(): string
  v:foldstart = 123
  return 'xxx'
enddef

def Test_assignment_failure()
  call CheckDefFailure(['let var=234'], 'E1004:')
  call CheckDefFailure(['let var =234'], 'E1004:')
  call CheckDefFailure(['let var= 234'], 'E1004:')

  call CheckDefFailure(['let true = 1'], 'E1034:')
  call CheckDefFailure(['let false = 1'], 'E1034:')

  call CheckDefFailure(['let [a; b; c] = g:list'], 'E452:')

  call CheckDefFailure(['let somevar'], "E1022:")
  call CheckDefFailure(['let &option'], 'E1052:')
  call CheckDefFailure(['&g:option = 5'], 'E113:')

  call CheckDefFailure(['let $VAR = 5'], 'E1065:')

  call CheckDefFailure(['let @~ = 5'], 'E354:')
  call CheckDefFailure(['let @a = 5'], 'E1066:')

  call CheckDefFailure(['let g:var = 5'], 'E1016:')
  call CheckDefFailure(['let w:var = 5'], 'E1079:')
  call CheckDefFailure(['let b:var = 5'], 'E1078:')
  call CheckDefFailure(['let t:var = 5'], 'E1080:')

  call CheckDefFailure(['let anr = 4', 'anr ..= "text"'], 'E1019:')
  call CheckDefFailure(['let xnr += 4'], 'E1020:')

  call CheckScriptFailure(['vim9script', 'def Func()', 'let dummy = s:notfound', 'enddef', 'defcompile'], 'E1050:')

  call CheckDefFailure(['let var: list<string> = [123]'], 'expected list<string> but got list<number>')
  call CheckDefFailure(['let var: list<number> = ["xx"]'], 'expected list<number> but got list<string>')

  call CheckDefFailure(['let var: dict<string> = #{key: 123}'], 'expected dict<string> but got dict<number>')
  call CheckDefFailure(['let var: dict<number> = #{key: "xx"}'], 'expected dict<number> but got dict<string>')

  call CheckDefFailure(['let var = feedkeys("0")'], 'E1031:')
  call CheckDefFailure(['let var: number = feedkeys("0")'], 'expected number but got void')

  call CheckDefFailure(['let var: dict <number>'], 'E1068:')
  call CheckDefFailure(['let var: dict<number'], 'E1009:')

  call assert_fails('s/^/\=Mess()/n', 'E794:')
  call CheckDefFailure(['let var: dict<number'], 'E1009:')
enddef

def Test_unlet()
  g:somevar = 'yes'
  assert_true(exists('g:somevar'))
  unlet g:somevar
  assert_false(exists('g:somevar'))
  unlet! g:somevar

  call CheckScriptFailure([
        'vim9script',
        'let svar = 123',
        'unlet svar',
        ], 'E1081:')
  call CheckScriptFailure([
        'vim9script',
        'let svar = 123',
        'unlet s:svar',
        ], 'E1081:')
  call CheckScriptFailure([
        'vim9script',
        'let svar = 123',
        'def Func()',
        '  unlet svar',
        'enddef',
        'defcompile',
        ], 'E1081:')
  call CheckScriptFailure([
        'vim9script',
        'let svar = 123',
        'def Func()',
        '  unlet s:svar',
        'enddef',
        'defcompile',
        ], 'E1081:')

  $ENVVAR = 'foobar'
  assert_equal('foobar', $ENVVAR)
  unlet $ENVVAR
  assert_equal('', $ENVVAR)
enddef

def Test_delfunction()
  " Check function is defined in script namespace
  CheckScriptSuccess([
      'vim9script',
      'func CheckMe()',
      '  return 123',
      'endfunc',
      'assert_equal(123, s:CheckMe())',
      ])

  " Check function in script namespace cannot be deleted
  CheckScriptFailure([
      'vim9script',
      'func DeleteMe1()',
      'endfunc',
      'delfunction DeleteMe1',
      ], 'E1084:')
  CheckScriptFailure([
      'vim9script',
      'func DeleteMe2()',
      'endfunc',
      'def DoThat()',
      '  delfunction DeleteMe2',
      'enddef',
      'DoThat()',
      ], 'E1084:')
  CheckScriptFailure([
      'vim9script',
      'def DeleteMe3()',
      'enddef',
      'delfunction DeleteMe3',
      ], 'E1084:')
  CheckScriptFailure([
      'vim9script',
      'def DeleteMe4()',
      'enddef',
      'def DoThat()',
      '  delfunction DeleteMe4',
      'enddef',
      'DoThat()',
      ], 'E1084:')
enddef

func Test_wrong_type()
  call CheckDefFailure(['let var: list<nothing>'], 'E1010:')
  call CheckDefFailure(['let var: list<list<nothing>>'], 'E1010:')
  call CheckDefFailure(['let var: dict<nothing>'], 'E1010:')
  call CheckDefFailure(['let var: dict<dict<nothing>>'], 'E1010:')

  call CheckDefFailure(['let var: dict<number'], 'E1009:')
  call CheckDefFailure(['let var: dict<list<number>'], 'E1009:')

  call CheckDefFailure(['let var: ally'], 'E1010:')
  call CheckDefFailure(['let var: bram'], 'E1010:')
  call CheckDefFailure(['let var: cathy'], 'E1010:')
  call CheckDefFailure(['let var: dom'], 'E1010:')
  call CheckDefFailure(['let var: freddy'], 'E1010:')
  call CheckDefFailure(['let var: john'], 'E1010:')
  call CheckDefFailure(['let var: larry'], 'E1010:')
  call CheckDefFailure(['let var: ned'], 'E1010:')
  call CheckDefFailure(['let var: pam'], 'E1010:')
  call CheckDefFailure(['let var: sam'], 'E1010:')
  call CheckDefFailure(['let var: vim'], 'E1010:')

  call CheckDefFailure(['let Ref: number', 'Ref()'], 'E1085:')
  call CheckDefFailure(['let Ref: string', 'let res = Ref()'], 'E1085:')
endfunc

func Test_const()
  call CheckDefFailure(['const var = 234', 'var = 99'], 'E1018:')
  call CheckDefFailure(['const one = 234', 'let one = 99'], 'E1017:')
  call CheckDefFailure(['const two'], 'E1021:')
  call CheckDefFailure(['const &option'], 'E996:')
endfunc

def Test_block()
  let outer = 1
  {
    let inner = 2
    assert_equal(1, outer)
    assert_equal(2, inner)
  }
  assert_equal(1, outer)
enddef

func Test_block_failure()
  call CheckDefFailure(['{', 'let inner = 1', '}', 'echo inner'], 'E1001:')
  call CheckDefFailure(['}'], 'E1025:')
  call CheckDefFailure(['{', 'echo 1'], 'E1026:')
endfunc

def Test_cmd_modifier()
  tab echo '0'
  call CheckDefFailure(['5tab echo 3'], 'E16:')
enddef

def Test_try_catch()
  let l = []
  try # comment
    add(l, '1')
    throw 'wrong'
    add(l, '2')
  catch # comment
    add(l, v:exception)
  finally # comment
    add(l, '3')
  endtry # comment
  assert_equal(['1', 'wrong', '3'], l)
enddef

def ThrowFromDef()
  throw "getout" # comment
enddef

func CatchInFunc()
  try
    call ThrowFromDef()
  catch
    let g:thrown_func = v:exception
  endtry
endfunc

def CatchInDef()
  try
    ThrowFromDef()
  catch
    g:thrown_def = v:exception
  endtry
enddef

def ReturnFinally(): string
  try
    return 'intry'
  finally
    g:in_finally = 'finally'
  endtry
  return 'end'
enddef

def Test_try_catch_nested()
  CatchInFunc()
  assert_equal('getout', g:thrown_func)

  CatchInDef()
  assert_equal('getout', g:thrown_def)

  assert_equal('intry', ReturnFinally())
  assert_equal('finally', g:in_finally)
enddef

def Test_try_catch_match()
  let seq = 'a'
  try
    throw 'something'
  catch /nothing/
    seq ..= 'x'
  catch /some/
    seq ..= 'b'
  catch /asdf/
    seq ..= 'x'
  catch ?a\?sdf?
    seq ..= 'y'
  finally
    seq ..= 'c'
  endtry
  assert_equal('abc', seq)
enddef

def Test_try_catch_fails()
  call CheckDefFailure(['catch'], 'E603:')
  call CheckDefFailure(['try', 'echo 0', 'catch','catch'], 'E1033:')
  call CheckDefFailure(['try', 'echo 0', 'catch /pat'], 'E1067:')
  call CheckDefFailure(['finally'], 'E606:')
  call CheckDefFailure(['try', 'echo 0', 'finally', 'echo 1', 'finally'], 'E607:')
  call CheckDefFailure(['endtry'], 'E602:')
  call CheckDefFailure(['while 1', 'endtry'], 'E170:')
  call CheckDefFailure(['for i in range(5)', 'endtry'], 'E170:')
  call CheckDefFailure(['if 2', 'endtry'], 'E171:')
  call CheckDefFailure(['try', 'echo 1', 'endtry'], 'E1032:')

  call CheckDefFailure(['throw'], 'E1015:')
  call CheckDefFailure(['throw xxx'], 'E1001:')
enddef

if has('channel')
  let someJob = test_null_job()

  def FuncWithError()
    echomsg g:someJob
  enddef

  func Test_convert_emsg_to_exception()
    try
      call FuncWithError()
    catch
      call assert_match('Vim:E908:', v:exception)
    endtry
  endfunc
endif

let s:export_script_lines =<< trim END
  vim9script
  let name: string = 'bob'
  def Concat(arg: string): string
    return name .. arg
  enddef
  g:result = Concat('bie')
  g:localname = name

  export const CONST = 1234
  export let exported = 9876
  export let exp_name = 'John'
  export def Exported(): string
    return 'Exported'
  enddef
END

def Test_vim9_import_export()
  let import_script_lines =<< trim END
    vim9script
    import {exported, Exported} from './Xexport.vim'
    g:imported = exported
    exported += 3
    g:imported_added = exported
    g:imported_func = Exported()

    import {exp_name} from './Xexport.vim'
    g:imported_name = exp_name
    exp_name ..= ' Doe'
    g:imported_name_appended = exp_name
    g:imported_later = exported
  END

  writefile(import_script_lines, 'Ximport.vim')
  writefile(s:export_script_lines, 'Xexport.vim')

  source Ximport.vim

  assert_equal('bobbie', g:result)
  assert_equal('bob', g:localname)
  assert_equal(9876, g:imported)
  assert_equal(9879, g:imported_added)
  assert_equal(9879, g:imported_later)
  assert_equal('Exported', g:imported_func)
  assert_equal('John', g:imported_name)
  assert_equal('John Doe', g:imported_name_appended)
  assert_false(exists('g:name'))

  unlet g:result
  unlet g:localname
  unlet g:imported
  unlet g:imported_added
  unlet g:imported_later
  unlet g:imported_func
  unlet g:imported_name g:imported_name_appended
  delete('Ximport.vim')

  let import_in_def_lines =<< trim END
    vim9script
    def ImportInDef()
      import exported from './Xexport.vim'
      g:imported = exported
      exported += 7
      g:imported_added = exported
    enddef
    ImportInDef()
  END
  writefile(import_in_def_lines, 'Ximport2.vim')
  source Ximport2.vim
  " TODO: this should be 9879
  assert_equal(9876, g:imported)
  assert_equal(9883, g:imported_added)
  unlet g:imported
  unlet g:imported_added
  delete('Ximport2.vim')

  let import_star_as_lines =<< trim END
    vim9script
    import * as Export from './Xexport.vim'
    def UseExport()
      g:imported = Export.exported
    enddef
    UseExport()
  END
  writefile(import_star_as_lines, 'Ximport.vim')
  source Ximport.vim
  assert_equal(9883, g:imported)

  let import_star_as_lines_no_dot =<< trim END
    vim9script
    import * as Export from './Xexport.vim'
    def Func()
      let dummy = 1
      let imported = Export + dummy
    enddef
    defcompile
  END
  writefile(import_star_as_lines_no_dot, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1060:')

  let import_star_as_lines_dot_space =<< trim END
    vim9script
    import * as Export from './Xexport.vim'
    def Func()
      let imported = Export . exported
    enddef
    defcompile
  END
  writefile(import_star_as_lines_dot_space, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1074:')

  let import_star_as_lines_missing_name =<< trim END
    vim9script
    import * as Export from './Xexport.vim'
    def Func()
      let imported = Export.
    enddef
    defcompile
  END
  writefile(import_star_as_lines_missing_name, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1048:')

  let import_star_lines =<< trim END
    vim9script
    import * from './Xexport.vim'
  END
  writefile(import_star_lines, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1045:')

  " try to import something that exists but is not exported
  let import_not_exported_lines =<< trim END
    vim9script
    import name from './Xexport.vim'
  END
  writefile(import_not_exported_lines, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1049:')

  " try to import something that is already defined
  let import_already_defined =<< trim END
    vim9script
    let exported = 'something'
    import exported from './Xexport.vim'
  END
  writefile(import_already_defined, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1073:')

  " try to import something that is already defined
  import_already_defined =<< trim END
    vim9script
    let exported = 'something'
    import * as exported from './Xexport.vim'
  END
  writefile(import_already_defined, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1073:')

  " try to import something that is already defined
  import_already_defined =<< trim END
    vim9script
    let exported = 'something'
    import {exported} from './Xexport.vim'
  END
  writefile(import_already_defined, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1073:')

  " import a very long name, requires making a copy
  let import_long_name_lines =<< trim END
    vim9script
    import name012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789 from './Xexport.vim'
  END
  writefile(import_long_name_lines, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1048:')

  let import_no_from_lines =<< trim END
    vim9script
    import name './Xexport.vim'
  END
  writefile(import_no_from_lines, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1070:')

  let import_invalid_string_lines =<< trim END
    vim9script
    import name from Xexport.vim
  END
  writefile(import_invalid_string_lines, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1071:')

  let import_wrong_name_lines =<< trim END
    vim9script
    import name from './XnoExport.vim'
  END
  writefile(import_wrong_name_lines, 'Ximport.vim')
  assert_fails('source Ximport.vim', 'E1053:')

  let import_missing_comma_lines =<< trim END
    vim9script
    import {exported name} from './Xexport.vim'
  END
  writefile(import_missing_comma_lines, 'Ximport3.vim')
  assert_fails('source Ximport3.vim', 'E1046:')

  delete('Ximport.vim')
  delete('Ximport3.vim')
  delete('Xexport.vim')

  " Check that in a Vim9 script 'cpo' is set to the Vim default.
  set cpo&vi
  let cpo_before = &cpo
  let lines =<< trim END
    vim9script
    g:cpo_in_vim9script = &cpo
  END
  writefile(lines, 'Xvim9_script')
  source Xvim9_script
  assert_equal(cpo_before, &cpo)
  set cpo&vim
  assert_equal(&cpo, g:cpo_in_vim9script)
  delete('Xvim9_script')
enddef

def Test_vim9script_fails()
  CheckScriptFailure(['scriptversion 2', 'vim9script'], 'E1039:')
  CheckScriptFailure(['vim9script', 'scriptversion 2'], 'E1040:')
  CheckScriptFailure(['export let some = 123'], 'E1042:')
  CheckScriptFailure(['import some from "./Xexport.vim"'], 'E1042:')
  CheckScriptFailure(['vim9script', 'export let g:some'], 'E1044:')
  CheckScriptFailure(['vim9script', 'export echo 134'], 'E1043:')

  assert_fails('vim9script', 'E1038')
  assert_fails('export something', 'E1043')
enddef

def Test_vim9script_reload_import()
  let lines =<< trim END
    vim9script
    const var = ''
    let valone = 1234
    def MyFunc(arg: string)
       valone = 5678
    enddef
  END
  let morelines =<< trim END
    let valtwo = 222
    export def GetValtwo(): number
      return valtwo
    enddef
  END
  writefile(lines + morelines, 'Xreload.vim')
  source Xreload.vim
  source Xreload.vim
  source Xreload.vim

  let testlines =<< trim END
    vim9script
    def TheFunc()
      import GetValtwo from './Xreload.vim'
      assert_equal(222, GetValtwo())
    enddef
    TheFunc()
  END
  writefile(testlines, 'Ximport.vim')
  source Ximport.vim

  " Test that when not using "morelines" GetValtwo() and valtwo are still
  " defined, because import doesn't reload a script.
  writefile(lines, 'Xreload.vim')
  source Ximport.vim

  " cannot declare a var twice
  lines =<< trim END
    vim9script
    let valone = 1234
    let valone = 5678
  END
  writefile(lines, 'Xreload.vim')
  assert_fails('source Xreload.vim', 'E1041:')

  delete('Xreload.vim')
  delete('Ximport.vim')
enddef

def Test_vim9script_reload_delfunc()
  let first_lines =<< trim END
    vim9script
    def FuncYes(): string
      return 'yes'
    enddef
  END
  let withno_lines =<< trim END
    def FuncNo(): string
      return 'no'
    enddef
    def g:DoCheck(no_exists: bool)
      assert_equal('yes', FuncYes())
      assert_equal('no', FuncNo())
    enddef
  END
  let nono_lines =<< trim END
    def g:DoCheck(no_exists: bool)
      assert_equal('yes', FuncYes())
      assert_fails('call FuncNo()', 'E117:')
    enddef
  END

  # FuncNo() is defined
  writefile(first_lines + withno_lines, 'Xreloaded.vim')
  source Xreloaded.vim
  g:DoCheck(true)

  # FuncNo() is not redefined
  writefile(first_lines + nono_lines, 'Xreloaded.vim')
  source Xreloaded.vim
  g:DoCheck()

  # FuncNo() is back
  writefile(first_lines + withno_lines, 'Xreloaded.vim')
  source Xreloaded.vim
  g:DoCheck()

  delete('Xreloaded.vim')
enddef

def Test_vim9script_reload_delvar()
  # write the script with a script-local variable
  let lines =<< trim END
    vim9script
    let var = 'string'
  END
  writefile(lines, 'XreloadVar.vim')
  source XreloadVar.vim

  # now write the script using the same variable locally - works
  lines =<< trim END
    vim9script
    def Func()
      let var = 'string'
    enddef
  END
  writefile(lines, 'XreloadVar.vim')
  source XreloadVar.vim

  delete('XreloadVar.vim')
enddef

def Test_import_absolute()
  let import_lines = [
        'vim9script',
        'import exported from "' .. escape(getcwd(), '\') .. '/Xexport_abs.vim"',
        'def UseExported()',
        '  g:imported_abs = exported',
        '  exported = 8888',
        '  g:imported_after = exported',
        'enddef',
        'UseExported()',
        'g:import_disassembled = execute("disass UseExported")',
        ]
  writefile(import_lines, 'Ximport_abs.vim')
  writefile(s:export_script_lines, 'Xexport_abs.vim')

  source Ximport_abs.vim

  assert_equal(9876, g:imported_abs)
  assert_equal(8888, g:imported_after)
  assert_match('<SNR>\d\+_UseExported.*' ..
          'g:imported_abs = exported.*' ..
          '0 LOADSCRIPT exported from .*Xexport_abs.vim.*' ..
          '1 STOREG g:imported_abs.*' ..
          'exported = 8888.*' ..
          '3 STORESCRIPT exported in .*Xexport_abs.vim.*' ..
          'g:imported_after = exported.*' ..
          '4 LOADSCRIPT exported from .*Xexport_abs.vim.*' ..
          '5 STOREG g:imported_after.*',
        g:import_disassembled)
  unlet g:imported_abs
  unlet g:import_disassembled

  delete('Ximport_abs.vim')
  delete('Xexport_abs.vim')
enddef

def Test_import_rtp()
  let import_lines = [
        'vim9script',
        'import exported from "Xexport_rtp.vim"',
        'g:imported_rtp = exported',
        ]
  writefile(import_lines, 'Ximport_rtp.vim')
  mkdir('import')
  writefile(s:export_script_lines, 'import/Xexport_rtp.vim')

  let save_rtp = &rtp
  &rtp = getcwd()
  source Ximport_rtp.vim
  &rtp = save_rtp

  assert_equal(9876, g:imported_rtp)
  unlet g:imported_rtp

  delete('Ximport_rtp.vim')
  delete('import', 'rf')
enddef

def Test_import_compile_error()
  let export_lines = [
        'vim9script',
        'export def ExpFunc(): string',
        '  return notDefined',
        'enddef',
        ]
  writefile(export_lines, 'Xexported.vim')

  let import_lines = [
        'vim9script',
        'import ExpFunc from "./Xexported.vim"',
        'def ImpFunc()',
        '  echo ExpFunc()',
        'enddef',
        'defcompile',
        ]
  writefile(import_lines, 'Ximport.vim')

  try
    source Ximport.vim
  catch /E1001/
    " Error should be fore the Xexported.vim file.
    assert_match('E1001: variable not found: notDefined', v:exception)
    assert_match('function <SNR>\d\+_ImpFunc\[1\]..<SNR>\d\+_ExpFunc, line 1', v:throwpoint)
  endtry

  delete('Xexported.vim')
  delete('Ximport.vim')
enddef

def Test_fixed_size_list()
  " will be allocated as one piece of memory, check that changes work
  let l = [1, 2, 3, 4]
  l->remove(0)
  l->add(5)
  l->insert(99, 1)
  assert_equal([2, 99, 3, 4, 5], l)
enddef

def IfElse(what: number): string
  let res = ''
  if what == 1
    res = "one"
  elseif what == 2
    res = "two"
  else
    res = "three"
  endif
  return res
enddef

def Test_if_elseif_else()
  assert_equal('one', IfElse(1))
  assert_equal('two', IfElse(2))
  assert_equal('three', IfElse(3))
enddef

def Test_if_elseif_else_fails()
  call CheckDefFailure(['elseif true'], 'E582:')
  call CheckDefFailure(['else'], 'E581:')
  call CheckDefFailure(['endif'], 'E580:')
  call CheckDefFailure(['if true', 'elseif xxx'], 'E1001:')
  call CheckDefFailure(['if true', 'echo 1'], 'E171:')
enddef

let g:bool_true = v:true
let g:bool_false = v:false

def Test_if_const_expr()
  let res = false
  if true ? true : false
    res = true
  endif
  assert_equal(true, res)

  g:glob = 2
  if false
    execute('let g:glob = 3')
  endif
  assert_equal(2, g:glob)
  if true
    execute('let g:glob = 3')
  endif
  assert_equal(3, g:glob)

  res = false
  if g:bool_true ? true : false
    res = true
  endif
  assert_equal(true, res)

  res = false
  if true ? g:bool_true : false
    res = true
  endif
  assert_equal(true, res)

  res = false
  if true ? true : g:bool_false
    res = true
  endif
  assert_equal(true, res)

  res = false
  if true ? false : true
    res = true
  endif
  assert_equal(false, res)

  res = false
  if false ? false : true
    res = true
  endif
  assert_equal(true, res)

  res = false
  if false ? true : false
    res = true
  endif
  assert_equal(false, res)

  res = false
  if has('xyz') ? true : false
    res = true
  endif
  assert_equal(false, res)

  res = false
  if true && true
    res = true
  endif
  assert_equal(true, res)

  res = false
  if true && false
    res = true
  endif
  assert_equal(false, res)

  res = false
  if g:bool_true && false
    res = true
  endif
  assert_equal(false, res)

  res = false
  if true && g:bool_false
    res = true
  endif
  assert_equal(false, res)

  res = false
  if false && false
    res = true
  endif
  assert_equal(false, res)

  res = false
  if true || false
    res = true
  endif
  assert_equal(true, res)

  res = false
  if g:bool_true || false
    res = true
  endif
  assert_equal(true, res)

  res = false
  if true || g:bool_false
    res = true
  endif
  assert_equal(true, res)

  res = false
  if false || false
    res = true
  endif
  assert_equal(false, res)
enddef

def Test_if_const_expr_fails()
  call CheckDefFailure(['if "aaa" == "bbb'], 'E114:')
  call CheckDefFailure(["if 'aaa' == 'bbb"], 'E115:')
  call CheckDefFailure(["if has('aaa'"], 'E110:')
  call CheckDefFailure(["if has('aaa') ? true false"], 'E109:')
enddef

def Test_execute_cmd()
  new
  setline(1, 'default')
  execute 'call setline(1, "execute-string")'
  assert_equal('execute-string', getline(1))

  execute "call setline(1, 'execute-string')"
  assert_equal('execute-string', getline(1))

  let cmd1 = 'call setline(1,'
  let cmd2 = '"execute-var")'
  execute cmd1 cmd2 # comment
  assert_equal('execute-var', getline(1))

  execute cmd1 cmd2 '|call setline(1, "execute-var-string")'
  assert_equal('execute-var-string', getline(1))

  let cmd_first = 'call '
  let cmd_last = 'setline(1, "execute-var-var")'
  execute cmd_first .. cmd_last
  assert_equal('execute-var-var', getline(1))
  bwipe!

  call CheckDefFailure(['execute xxx'], 'E1001:')
  call CheckDefFailure(['execute "cmd"# comment'], 'E488:')
enddef

def Test_echo_cmd()
  echo 'some' # comment
  echon 'thing'
  assert_match('^something$', Screenline(&lines))

  echo "some" # comment
  echon "thing"
  assert_match('^something$', Screenline(&lines))

  let str1 = 'some'
  let str2 = 'more'
  echo str1 str2
  assert_match('^some more$', Screenline(&lines))

  call CheckDefFailure(['echo "xxx"# comment'], 'E488:')
enddef

def Test_echomsg_cmd()
  echomsg 'some' 'more' # comment
  assert_match('^some more$', Screenline(&lines))
  echo 'clear'
  1messages
  assert_match('^some more$', Screenline(&lines))

  call CheckDefFailure(['echomsg "xxx"# comment'], 'E488:')
enddef

def Test_echoerr_cmd()
  try
    echoerr 'something' 'wrong' # comment
  catch
    assert_match('something wrong', v:exception)
  endtry
enddef

def Test_for_outside_of_function()
  let lines =<< trim END
    vim9script
    new
    for var in range(0, 3)
      append(line('$'), var)
    endfor
    assert_equal(['', '0', '1', '2', '3'], getline(1, '$'))
    bwipe!
  END
  writefile(lines, 'Xvim9for.vim')
  source Xvim9for.vim
  delete('Xvim9for.vim')
enddef

def Test_for_loop()
  let result = ''
  for cnt in range(7)
    if cnt == 4
      break
    endif
    if cnt == 2
      continue
    endif
    result ..= cnt .. '_'
  endfor
  assert_equal('0_1_3_', result)
enddef

def Test_for_loop_fails()
  CheckDefFailure(['for # in range(5)'], 'E690:')
  CheckDefFailure(['for i In range(5)'], 'E690:')
  CheckDefFailure(['let x = 5', 'for x in range(5)'], 'E1023:')
  CheckScriptFailure(['def Func(arg: any)', 'for arg in range(5)', 'enddef', 'defcompile'], 'E1006:')
  CheckDefFailure(['for i in "text"'], 'E1024:')
  CheckDefFailure(['for i in xxx'], 'E1001:')
  CheckDefFailure(['endfor'], 'E588:')
  CheckDefFailure(['for i in range(3)', 'echo 3'], 'E170:')
enddef

def Test_while_loop()
  let result = ''
  let cnt = 0
  while cnt < 555
    if cnt == 3
      break
    endif
    cnt += 1
    if cnt == 2
      continue
    endif
    result ..= cnt .. '_'
  endwhile
  assert_equal('1_3_', result)
enddef

def Test_while_loop_fails()
  CheckDefFailure(['while xxx'], 'E1001:')
  CheckDefFailure(['endwhile'], 'E588:')
  CheckDefFailure(['continue'], 'E586:')
  CheckDefFailure(['if true', 'continue'], 'E586:')
  CheckDefFailure(['break'], 'E587:')
  CheckDefFailure(['if true', 'break'], 'E587:')
  CheckDefFailure(['while 1', 'echo 3'], 'E170:')
enddef

def Test_interrupt_loop()
  let caught = false
  let x = 0
  try
    while 1
      x += 1
      if x == 100
        feedkeys("\<C-C>", 'Lt')
      endif
    endwhile
  catch
    caught = true
    assert_equal(100, x)
  endtry
  assert_true(caught, 'should have caught an exception')
enddef

def Test_automatic_line_continuation()
  let mylist = [
      'one',
      'two',
      'three',
      ] " comment
  assert_equal(['one', 'two', 'three'], mylist)

  let mydict = {
      'one': 1,
      'two': 2,
      'three':
          3,
      } " comment
  assert_equal({'one': 1, 'two': 2, 'three': 3}, mydict)
  mydict = #{
      one: 1,  # comment
      two:     # comment
           2,  # comment
      three: 3 # comment
      }
  assert_equal(#{one: 1, two: 2, three: 3}, mydict)
  mydict = #{
      one: 1, 
      two: 
           2, 
      three: 3 
      }
  assert_equal(#{one: 1, two: 2, three: 3}, mydict)

  assert_equal(
        ['one', 'two', 'three'],
        split('one two three')
        )
enddef

def Test_vim9_comment()
  CheckScriptSuccess([
      'vim9script',
      '# something',
      ])
  CheckScriptFailure([
      'vim9script',
      ':# something',
      ], 'E488:')
  CheckScriptFailure([
      '# something',
      ], 'E488:')
  CheckScriptFailure([
      ':# something',
      ], 'E488:')

  { # block start
  } # block end
  CheckDefFailure([
      '{# comment',
      ], 'E488:')
  CheckDefFailure([
      '{',
      '}# comment',
      ], 'E488:')

  echo "yes" # comment
  CheckDefFailure([
      'echo "yes"# comment',
      ], 'E488:')
  CheckScriptSuccess([
      'vim9script',
      'echo "yes" # something',
      ])
  CheckScriptFailure([
      'vim9script',
      'echo "yes"# something',
      ], 'E121:')
  CheckScriptFailure([
      'vim9script',
      'echo# something',
      ], 'E121:')
  CheckScriptFailure([
      'echo "yes" # something',
      ], 'E121:')

  exe "echo" # comment
  CheckDefFailure([
      'exe "echo"# comment',
      ], 'E488:')
  CheckScriptSuccess([
      'vim9script',
      'exe "echo" # something',
      ])
  CheckScriptFailure([
      'vim9script',
      'exe "echo"# something',
      ], 'E121:')
  CheckDefFailure([
      'exe # comment',
      ], 'E1015:')
  CheckScriptFailure([
      'vim9script',
      'exe# something',
      ], 'E121:')
  CheckScriptFailure([
      'exe "echo" # something',
      ], 'E121:')

  CheckDefFailure([
      'try# comment',
      '  echo "yes"',
      'catch',
      'endtry',
      ], 'E488:')
  CheckScriptFailure([
      'vim9script',
      'try# comment',
      'echo "yes"',
      ], 'E488:')
  CheckDefFailure([
      'try',
      '  throw#comment',
      'catch',
      'endtry',
      ], 'E1015:')
  CheckDefFailure([
      'try',
      '  throw "yes"#comment',
      'catch',
      'endtry',
      ], 'E488:')
  CheckDefFailure([
      'try',
      '  echo "yes"',
      'catch# comment',
      'endtry',
      ], 'E488:')
  CheckScriptFailure([
      'vim9script',
      'try',
      '  echo "yes"',
      'catch# comment',
      'endtry',
      ], 'E654:')
  CheckDefFailure([
      'try',
      '  echo "yes"',
      'catch /pat/# comment',
      'endtry',
      ], 'E488:')
  CheckDefFailure([
      'try',
      'echo "yes"',
      'catch',
      'endtry# comment',
      ], 'E488:')
  CheckScriptFailure([
      'vim9script',
      'try',
      '  echo "yes"',
      'catch',
      'endtry# comment',
      ], 'E600:')

  CheckScriptSuccess([
      'vim9script',
      'hi # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'hi# comment',
      ], 'E416:')
  CheckScriptSuccess([
      'vim9script',
      'hi Search # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'hi Search# comment',
      ], 'E416:')
  CheckScriptSuccess([
      'vim9script',
      'hi link This Search # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'hi link This That# comment',
      ], 'E413:')
  CheckScriptSuccess([
      'vim9script',
      'hi clear This # comment',
      'hi clear # comment',
      ])
  " not tested, because it doesn't give an error but a warning:
  " hi clear This# comment',
  CheckScriptFailure([
      'vim9script',
      'hi clear# comment',
      ], 'E416:')

  CheckScriptSuccess([
      'vim9script',
      'hi Group term=bold',
      'match Group /todo/ # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'hi Group term=bold',
      'match Group /todo/# comment',
      ], 'E488:')
  CheckScriptSuccess([
      'vim9script',
      'match # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'match# comment',
      ], 'E475:')
  CheckScriptSuccess([
      'vim9script',
      'match none # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'match none# comment',
      ], 'E475:')

  CheckScriptSuccess([
      'vim9script',
      'menutrans clear # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'menutrans clear# comment text',
      ], 'E474:')

  CheckScriptSuccess([
      'vim9script',
      'syntax clear # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'syntax clear# comment text',
      ], 'E28:')
  CheckScriptSuccess([
      'vim9script',
      'syntax keyword Word some',
      'syntax clear Word # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'syntax keyword Word some',
      'syntax clear Word# comment text',
      ], 'E28:')

  CheckScriptSuccess([
      'vim9script',
      'syntax list # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'syntax list# comment text',
      ], 'E28:')

  CheckScriptSuccess([
      'vim9script',
      'syntax match Word /pat/ oneline # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'syntax match Word /pat/ oneline# comment',
      ], 'E475:')

  CheckScriptSuccess([
      'vim9script',
      'syntax keyword Word word # comm[ent',
      ])
  CheckScriptFailure([
      'vim9script',
      'syntax keyword Word word# comm[ent',
      ], 'E789:')

  CheckScriptSuccess([
      'vim9script',
      'syntax match Word /pat/ # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'syntax match Word /pat/# comment',
      ], 'E402:')

  CheckScriptSuccess([
      'vim9script',
      'syntax match Word /pat/ contains=Something # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'syntax match Word /pat/ contains=Something# comment',
      ], 'E475:')
  CheckScriptFailure([
      'vim9script',
      'syntax match Word /pat/ contains= # comment',
      ], 'E406:')
  CheckScriptFailure([
      'vim9script',
      'syntax match Word /pat/ contains=# comment',
      ], 'E475:')

  CheckScriptSuccess([
      'vim9script',
      'syntax region Word start=/pat/ end=/pat/ # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'syntax region Word start=/pat/ end=/pat/# comment',
      ], 'E475:')

  CheckScriptSuccess([
      'vim9script',
      'syntax sync # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'syntax sync# comment',
      ], 'E404:')
  CheckScriptSuccess([
      'vim9script',
      'syntax sync ccomment # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'syntax sync ccomment# comment',
      ], 'E404:')

  CheckScriptSuccess([
      'vim9script',
      'syntax cluster Some contains=Word # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'syntax cluster Some contains=Word# comment',
      ], 'E475:')

  CheckScriptSuccess([
      'vim9script',
      'command Echo echo # comment',
      'command Echo # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'command Echo echo# comment',
      'Echo',
      ], 'E121:')
  CheckScriptFailure([
      'vim9script',
      'command Echo# comment',
      ], 'E182:')
  CheckScriptFailure([
      'vim9script',
      'command Echo echo',
      'command Echo# comment',
      ], 'E182:')

  CheckScriptSuccess([
      'vim9script',
      'function # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'function# comment',
      ], 'E129:')
  CheckScriptSuccess([
      'vim9script',
      'function CheckScriptSuccess # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'function CheckScriptSuccess# comment',
      ], 'E488:')

  CheckScriptSuccess([
      'vim9script',
      'func g:DeleteMeA()',
      'endfunc',
      'delfunction g:DeleteMeA # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'func g:DeleteMeB()',
      'endfunc',
      'delfunction g:DeleteMeB# comment',
      ], 'E488:')

  CheckScriptSuccess([
      'vim9script',
      'call execute("ls") # comment',
      ])
  CheckScriptFailure([
      'vim9script',
      'call execute("ls")# comment',
      ], 'E488:')
enddef

def Test_vim9_comment_gui()
  CheckCanRunGui

  CheckScriptFailure([
      'vim9script',
      'gui#comment'
      ], 'E499:')
  CheckScriptFailure([
      'vim9script',
      'gui -f#comment'
      ], 'E499:')
enddef

def Test_vim9_comment_not_compiled()
  au TabEnter *.vim let g:entered = 1
  au TabEnter *.x let g:entered = 2

  edit test.vim
  doautocmd TabEnter #comment
  assert_equal(1, g:entered)

  doautocmd TabEnter f.x
  assert_equal(2, g:entered)

  g:entered = 0
  doautocmd TabEnter f.x #comment
  assert_equal(2, g:entered)

  assert_fails('doautocmd Syntax#comment', 'E216:')

  au! TabEnter
  unlet g:entered

  CheckScriptSuccess([
      'vim9script',
      'let g:var = 123',
      'let w:var = 777',
      'unlet g:var w:var # something',
      ])

  CheckScriptFailure([
      'vim9script',
      'let g:var = 123',
      'unlet g:var# comment1',
      ], 'E108:')

  CheckScriptFailure([
      'let g:var = 123',
      'unlet g:var # something',
      ], 'E488:')

  CheckScriptSuccess([
      'vim9script',
      'if 1 # comment2',
      '  echo "yes"',
      'elseif 2 #comment',
      '  echo "no"',
      'endif',
      ])

  CheckScriptFailure([
      'vim9script',
      'if 1# comment3',
      '  echo "yes"',
      'endif',
      ], 'E15:')

  CheckScriptFailure([
      'vim9script',
      'if 0 # comment4',
      '  echo "yes"',
      'elseif 2#comment',
      '  echo "no"',
      'endif',
      ], 'E15:')

  CheckScriptSuccess([
      'vim9script',
      'let v = 1 # comment5',
      ])

  CheckScriptFailure([
      'vim9script',
      'let v = 1# comment6',
      ], 'E15:')

  CheckScriptSuccess([
      'vim9script',
      'new'
      'call setline(1, ["# define pat", "last"])',
      '$',
      'dsearch /pat/ #comment',
      'bwipe!',
      ])

  CheckScriptFailure([
      'vim9script',
      'new'
      'call setline(1, ["# define pat", "last"])',
      '$',
      'dsearch /pat/#comment',
      'bwipe!',
      ], 'E488:')

  CheckScriptFailure([
      'vim9script',
      'func! SomeFunc()',
      ], 'E477:')
enddef

def Test_finish()
  let lines =<< trim END
    vim9script
    let g:res = 'one'
    if v:false | finish | endif
    let g:res = 'two'
    finish
    let g:res = 'three'
  END
  writefile(lines, 'Xfinished')
  source Xfinished
  assert_equal('two', g:res)

  unlet g:res
  delete('Xfinished')
enddef

def Test_let_func_call()
  let lines =<< trim END
    vim9script
    func GetValue()
      if exists('g:count')
        let g:count += 1
      else
        let g:count = 1
      endif
      return 'this'
    endfunc
    let val: string = GetValue() 
    " env var is always a string
    let env = $TERM
  END
  writefile(lines, 'Xfinished')
  source Xfinished
  " GetValue() is not called during discovery phase
  assert_equal(1, g:count)

  unlet g:count
  delete('Xfinished')
enddef

def Test_let_missing_type()
  let lines =<< trim END
    vim9script
    let var = g:unknown
  END
  CheckScriptFailure(lines, 'E121:')

  lines =<< trim END
    vim9script
    let nr: number = 123
    let var = nr
  END
  CheckScriptSuccess(lines)
enddef

def Test_forward_declaration()
  let lines =<< trim END
    vim9script
    def GetValue(): string
      return theVal
    enddef
    let theVal = 'something'
    g:initVal = GetValue()
    theVal = 'else'
    g:laterVal = GetValue()
  END
  writefile(lines, 'Xforward')
  source Xforward
  assert_equal('something', g:initVal)
  assert_equal('else', g:laterVal)

  unlet g:initVal
  unlet g:laterVal
  delete('Xforward')
enddef


" Keep this last, it messes up highlighting.
def Test_substitute_cmd()
  new
  setline(1, 'something')
  :substitute(some(other(
  assert_equal('otherthing', getline(1))
  bwipe!

  " also when the context is Vim9 script
  let lines =<< trim END
    vim9script
    new
    setline(1, 'something')
    :substitute(some(other(
    assert_equal('otherthing', getline(1))
    bwipe!
  END
  writefile(lines, 'Xvim9lines')
  source Xvim9lines

  delete('Xvim9lines')
enddef

" vim: ts=8 sw=2 sts=2 expandtab tw=80 fdm=marker