ale/test/test_prepare_command.vader

Before:
  Save &shell
  Save &shellcmdflag

After:
  Restore

Execute(sh should be used when the shell is fish):
  if !has('win32')
    " Set something else, so we will replace that too.
    let &shellcmdflag = '-f'
    let &shell = 'fish'

    AssertEqual ['/bin/sh', '-c', 'foobar'], ale#job#PrepareCommand(bufnr(''), 'foobar')

    let &shell = '/usr/bin/fish'

    AssertEqual ['/bin/sh', '-c', 'foobar'], ale#job#PrepareCommand(bufnr(''), 'foobar')

    let &shell = '/usr/local/bin/fish'

    AssertEqual ['/bin/sh', '-c', 'foobar'], ale#job#PrepareCommand(bufnr(''), 'foobar')
  endif

Execute(Other shells should be used when set):
  if !has('win32')
    let &shell = '/bin/bash'
    let &shellcmdflag = '-c'

    AssertEqual ['/bin/bash', '-c', 'foobar'], ale#job#PrepareCommand(bufnr(''), 'foobar')
  endif

Execute(cmd /s/c as a string should be used on Windows):
  if has('win32')
    let &shell = 'who cares'
    let &shellcmdflag = 'whatever'

    AssertEqual 'cmd /s/c "foobar"', ale#job#PrepareCommand(bufnr(''), 'foobar')
  endif