In this chapter, we crafted unit tests using JUnit and AssertJ. Then we performed slice-based tests against MongoDB using Spring Boot's @DataMongoTest annotation, with and without embedded MongoDB. We tested WebFlux controllers, ensuring they operated correctly. We also wrote end-to-end tests with Spring Boot spinning up an entire embedded web container so that Selenium WebDriver could drive it from the browser. Finally, we put together an autoconfiguration policy for Selenium WebDriver using test-first practices to verify that it worked.

In the next chapter, we will explore the developer tools provided by Spring Boot to ease the tasks we all must deal with.