Spock is a testing and specification framework for Java and Groovy applications. What makes it stand out from the crowd is its beautiful and highly expressive specification language. Thanks to its JUnit runner, Spock is compatible with most IDEs, build tools, and continuous integration servers. Spock is inspired from JUnit, jMock, RSpec, Groovy, Scala, Vulcans, and other fascinating life forms.
Have a look at Rob Fletcher’s presentation. If you use Spock, this presentation will help you to write better tests. If don’t use, it’s time to upgrade your set of test and expressiveness.
Never trust a test you haven’t seen fail.
More of his examples on GitHub.