Summary

This chapter has discussed the various stages at which we can write tests – before we write code, after we write code, or possibly even never. It has made a case for writing tests before code as providing the most value in terms of valid execution path coverage and developer ease. We went on to review how hexagonal architecture interacts with both TDD and the test pyramid, leading to an opportunity to bring user story testing into the realm of FIRST unit tests. This allows the fast and repeatable validation of the core logic driving our user stories.

In the next chapter – and throughout the third part of the book – we will return to building our Wordz application. We will be making full use of all the techniques we’ve learned so far. We will begin inside-out with Chapter 13, Driving the Domain Layer.