TDD, DDD and Encapsulation

Question

After several years of following the bad practice handed down from \'architects\' at my place of work and thinking that there must be a better way, I\'ve recently been reading u

Answer 1

I call a system's public input methods (i.e. I push input data into the system), and then I get (and assert) the system's output. I'm not testing the system's internal state, but rather its public/visible behaviour: Should one test internal implementation, or only test public behaviour?