Pablo Herrero

There are many examples at https://github.com/rails/rails/blob/master/railties/test/generators For example here: https://github.com/rails/rails/blob/master/railties/test/generators/model_generator_test.rb You can see an assertion that tests file existence and its contents at the same time. Or another one that...

There is something like that here: https://github.com/mislav/rspec-rails-mocha. Maybe is useful as a reference since it's not clear whether the author have abandoned the gem.

@georgemillo, did you released the gem?. I also found this other one [dry-validation-matchers](https://github.com/imacchiato/dry-validation-matchers) but is no very comprehensive yet and is not using the reflection approach either.