Building Microservices, 2nd Edition

Chapter 9. Testing

The world of automated testing has advanced significantly since I first started writing code, and every month there seems to be some new tool or technique to make it even better. But challenges remain regarding how to effectively and efficiently test our code’s functionality when it spans a distributed system. This chapter breaks down the problems associated with testing finer-grained systems and presents some solutions to help you make sure you can release your new functionality with confidence.

Testing covers a lot of ground. Even when we are talking only about automated tests, there are a large number to consider. With microservices, we have added another level of complexity. Understanding what different types of tests we can run is important to help us balance the sometimes-opposing forces of getting our software into production as quickly as possible versus making sure our software is of sufficient quality. Given the scope of testing as a whole, I am not going to attempt a broad exploration of the topic. Instead, this chapter is primarily focused on looking at how testing of a microservice architecture is different when compared to less-distributed systems such as single-process monolithic applications.

Where testing is done has also shifted since the first edition of this book. Previously, testing was predominantly carried out before the software got to production. Increasingly, though, we look at testing our applications once they arrive in production—further ...