Before:
  Save g:ale_sh_shfmt_executable
  Save g:ale_sh_shfmt_options

After:
  Restore

Execute(The shfmt callback should return the correct default values):
  AssertEqual
  \ {
  \   'command': ale#Escape('shfmt'),
  \ },
  \ ale#fixers#shfmt#Fix(bufnr(''))

Execute(The shfmt executable and options should be configurable):
  let g:ale_sh_shfmt_executable = 'foobar'
  let g:ale_sh_shfmt_options = '--some-option'

  AssertEqual
  \ {
  \   'command': ale#Escape('foobar')
  \     . ' --some-option',
  \ },
  \ ale#fixers#shfmt#Fix(bufnr(''))