Defining test boundaries with hexagonal architecture
The topic for this section is how using a hexagonal architecture impacts TDD. Knowing that we are using hexagonal architecture presents useful boundaries for the different kinds of tests in the test pyramid.
In one sense, how we organize our code base does not affect our use of TDD. The internal structure of the code is simply an implementation detail, one of many possibilities that will make our tests pass. That being said, some ways of structuring our code are easier to work with than others. Using hexagonal architecture as a foundational structure does offer TDD some advantages. The reason why lies with the use of ports and adapters.
We’ve learned from previous chapters that it is easier to write tests for code where we can control the environment in which the code runs. We’ve seen how the test pyramid gives a structure to the different kinds of tests we write. Using the ports and adapters approach provides...
