Before:
  Save g:ale_purescript_tidy_executable
  Save g:ale_purescript_tidy_options

  " Use an invalid global executable, so we don’t match it.
  let g:ale_purescript_tidy_executable = 'odd-purs-tidy'
  let g:ale_purescript_tidy_options = '--indent 3'

  call ale#assert#SetUpFixerTest('purescript', 'purs-tidy')

After:
  call ale#assert#TearDownFixerTest()

Execute(The purs-tidy callback should return the correct custom options):
  AssertFixer
  \ {
  \   'command': ale#Escape('odd-purs-tidy')
  \     . ' format'
  \     . ' --indent 3'
  \ }