Before:
  call ale#test#SetDirectory('/testplugin/test')

After:
  noautocmd :e! ++ff=unix
  setlocal buftype=nofile

  if filereadable('.newline-test')
    call delete('.newline-test')
  endif

  call ale#test#RestoreDirectory()

Given(A file with Windows line ending characters):
  first
  second
  third

Execute(Carriage returns should be included for ale#util#Writefile):
  call ale#test#SetFilename('.newline-test')

  setlocal buftype=
  noautocmd :w
  noautocmd :e! ++ff=dos

  call ale#util#Writefile(bufnr(''), getline(1, '$'), '.newline-test')

  AssertEqual
  \ ["first\r", "second\r", "third\r", ''],
  \ readfile('.newline-test', 'b')
  \
Given(A file with Unix line ending characters):
  first
  second
  third

Execute(Unix file lines should be written as normal):
  call ale#test#SetFilename('.newline-test')

  setlocal buftype=
  noautocmd :w
  noautocmd :e! ++ff=unix

  call ale#util#Writefile(bufnr(''), getline(1, '$'), '.newline-test')

  AssertEqual
  \ ['first', 'second', 'third', ''],
  \ readfile('.newline-test', 'b')