Rails, Is there a way to generate Unit Tests from Existing Controllers and methods defined in them?

I was wondering if there is a script that can take existing codebase and generate unit tests for each method in controllers. By default all would be passing since they would be empty and i can remove tests i for methods i dont feel important.

This would save huge time and increase testing. Since i'd have to define only what each method should output and not boilerplate that needs to be written.