Summary

So we have discussed what Persistence Ignorance is and some ideas of how to keep the infrastructure out of the Domain Model classes, while at the same time prepare for infrastructure. We also discussed database testing, and a lot of attention was spent on an idea of introducing an abstraction layer.

In the next chapter, we will change focus to the core of the Domain Model again, this time focusing on rules. You will find that lots of the requirements in the list we set up in Chapter 4 are about rules, so this is a near and dear topic when Domain Models are discussed.