Before:
  call ale#test#SetDirectory('/testplugin/test/fixers')

After:
  Restore

  call ale#test#RestoreDirectory()

Execute(The hlint callback should return the correct default values):
  call ale#test#SetFilename('../haskell_files/testfile.hs')

  AssertEqual
  \ {
  \   'read_temporary_file': 1,
  \   'command': ale#Escape('hlint')
  \     . ' --refactor'
  \     . ' --refactor-options="--inplace"'
  \     . ' %t',
  \ },
  \ ale#fixers#hlint#Fix(bufnr(''))