Designing Elixir Systems With OTP

Chapter 10 Test the Boundary

We’ve finally reached the last chapter of this book. We’re going to test the boundary layers of Mastery, the “big loud worker-bees” words of our sentence. These layers deal with the boundary API, lifecycles, and workers. As a bonus, we’ll also test the external component we introduced in Chapter 9, ​ Assemble Your Components ​.

As we work through our tests, we’ll need to deal with some complex issues that were not on the table when we tested the relatively pure core layers in Chapter 5, ​ Test Your Core ​. Luckily, our layering system means we won’t have to repeat the core-centered tests of the pure business logic. We’ll focus on the complexity of the machinery dealing with processes, timing, and external interfaces. ...