Hands-On Reactive Programming in Spring 5

Essentials of StepVerifier

There are two main methods for verifying a Publisher. The first one is StepVerifier.<T>create(Publisher<T> source). The test that can be built with this technique looks like the following:

StepVerifier   .create(Flux.just("foo", "bar"))
   .expectSubscription()
   .expectNext("foo")
   .expectNext("bar")
   .expectComplete()
   .verify();

In this example, our Publisher should produce two particular elements, and subsequent operations verify whether particular elements have been delivered to the final subscriber. From the preceding example, we might understand the workings of a part of the StepVerifier API. The builder technique offered by that class allows us to define the order in which events will occur during the verification ...