Using isolation as a feature

The beauty of microservices is that they are, by definition, as isolated as possible. Consequently testing microservices can be very simple and comprehensive without much work. What the unit test is to the whole software is what a functional test is to a microservice setup. The benefit of testing is that each service can be tested without looking at the other services. That allows us to find any errors before they even surface.

Let's look at a few examples of where you can see this benefit.

Reusable services

In Chapter 7, Writing the User Service, you developed a user management service. You wrote this service only once, but you may be able to use it in different projects. Once you have finished...