Hands-On Reactive Programming in Spring 5

The Subscriber verification

The mentioned configurations are the minimum that are required in order to start testing our producer's behavior. However, along with the instances of  Publisher, we have instances of  Subscriber that should be tested as well. Fortunately, that group of rules in the Reactive Stream specification is less complex than Publisher's one, but it is still required to satisfy all requirements.

There are two different test suits to test NewsServiceSubscriber. The first one is called org.reactivestreams.tck.SubscriberBlackboxVerification, which allows verifying the Subscriber without knowledge or modification of its internals. Blackbox verification is a useful test kit when the Subscriber comes from the external codebase, ...