+1  A: 

I just changed my autotest to:

Autotest.add_hook :initialize do |at|
  at.add_mapping(%r%^spec/acceptance/.*_spec.rb$%, true) { |filename, _|
    filename
  }

  at.add_mapping(%r%^app/(models|controllers|helpers|lib)/.*rb$%, true) {
    at.files_matching %r%^spec/acceptance/.*_spec.rb$%
  }

  at.add_mapping(%r%^app/views/(.*)$%, true) {
    at.files_matching %r%^spec/acceptance/.*_spec.rb$%
  }
end

And this is working but I don't know the collateral effects of invoking acceptance tests before others (the true flag on add_mapping)

Gabriel Sobrinho
Hey Gabriel, thanks your response and sorry for my (huge) delay in getting back. I couldn't test this as the project was dropped, but it's worth mentioning that, afterwards, I found that making it work like it does with Cucumber is just way more involved than I originally imagined.
digiberber