How to test an Orb's jobs and commands failure modes

I’m looking for examples of how to write orb integration tests to confirm that orb jobs and commands fail when they should.

For example, I’m working on an orb that validates a file meets a given spec - I can easily write tests that show the orb job succeeding on a well formatted file, but there is no way for me to validate that the job fails on a badly formatted file.

Any ideas?