Before:
  Save g:ale_haskell_fourmolu_executable
  Save g:ale_haskell_fourmolu_options

After:
  Restore

Execute(The fourmolu callback should return the correct default values):
  AssertEqual
  \ {
  \   'command': ale#Escape('fourmolu')
  \     . ' --stdin-input-file '
  \     . ale#Escape(@%)
  \ },
  \ ale#fixers#fourmolu#Fix(bufnr(''))

Execute(The fourmolu executable and options should be configurable):
  let g:ale_haskell_fourmolu_executable = '/path/to/fourmolu'
  let g:ale_haskell_fourmolu_options = '-h'

  AssertEqual
  \ {
  \   'command': ale#Escape('/path/to/fourmolu')
  \     . ' -h'
  \     . ' --stdin-input-file '
  \     . ale#Escape(@%)
  \ },
  \ ale#fixers#fourmolu#Fix(bufnr(''))