Rails 5 Test Prescriptions

The World Is a Service

Once you get used to the idea of having adapters mediate access between your application and external services, it’s not that far a leap to have adapters internally to mediate between different parts of your application. This approach is sometimes called hexagonal architecture, and many resources can be found online that describe hexagonal architecture as it applies to Rails.^[71] At the same time you can find many resources online saying that hexagonal architecture is an awful idea. (David Heinemeier Hansson is a particularly vocal critic.)

You’ve taken baby steps in this direction by creating action objects such as CreatesProject, which are somewhat like adapters between the controller and the model. Many web frameworks ...