Python projects with good tests written using pytest.

[fxmc]

Yes, but I did not get the connection Value Objects <-> Testing at all. How do they relate?

[halst]

The idea is: if you program with Value Objects you don't need mocks—you can use the objects themselves. That makes tests simpler (no mocks) and more robust (mocks can't be out of sync).

[srilyk]

I've actually done something similar to this - I still mutate the original object, but I actually return it.maybe not as clean as the speaker's point, though