Before:
  Save g:ale_python_isort_executable

  " Use an invalid global executable, so we don't match it.
  let g:ale_python_isort_executable = 'xxxinvalid'

  call ale#test#SetDirectory('/testplugin/test/fixers')
  silent cd ..
  silent cd command_callback
  let g:dir = getcwd()

  let b:bin_dir = has('win32') ? 'Scripts' : 'bin'

After:
  Restore

  unlet! b:bin_dir

  call ale#test#RestoreDirectory()

Execute(The isort callback should return the correct default values):
  AssertEqual
  \ 0,
  \ ale#fixers#isort#Fix(bufnr(''))

  silent execute 'file ' . fnameescape(g:dir . '/python_paths/with_virtualenv/subdir/foo/bar.py')
  AssertEqual
  \ {
  \   'command': 'cd ' . ale#Escape(ale#path#Simplify(g:dir . '/python_paths/with_virtualenv/subdir/foo')) .  ' && '
  \     . ale#Escape(ale#path#Simplify(g:dir . '/python_paths/with_virtualenv/env/' . b:bin_dir . '/isort')) . ' -',
  \ },
  \ ale#fixers#isort#Fix(bufnr(''))