spock
Spock is a powerful Groovy-based framework that makes testing applications written in Java (as well as Groovy, Kotlin etc.) a very pleasant experience. Because it’s built on top of good ol’ JUnit, it integrates well with most of the existing test/build tooling. However, making it play nicely with the testing infrastructure of Spring framework (especially Spring Boot) used to be a bit tricky. Luckily, the latest Spock version 1.1 comes with a few improvements that make testing Spring apps (including mocking) easier.