Before:
  call ale#assert#SetUpFixerTest('nix', 'statix')

After:
  call ale#assert#TearDownFixerTest()

Execute(The callback should return the correct default values):
  AssertFixer { 'command': ale#Escape('statix') . ' fix --stdin' }

Execute(The callback should include a custom runtime):
  let g:ale_nix_statix_fix_executable = 'foo/bar'

  AssertFixer { 'command': ale#Escape('foo/bar') . ' fix --stdin' }

Execute(The callback should include custom options):
  let g:ale_nix_statix_fix_options = '--foobar'

  AssertFixer { 'command': ale#Escape('statix') . ' fix --stdin --foobar' }
