Finally, one topic that should be covered here is the verification of streaming systems. In this section, we will cover the testing of the WebSocket server and client only. As we will learn in Chapter 6, WebFlux Async Non-Blocking Communication, along with the WebSocket API, there is a Server-Sent Events (SSE) protocol for streaming data, which gives us similar capabilities. Nevertheless, since the implementation of SSE is almost identical to the implementation of the regular controller, all verification techniques from the previous section will be valid for that case as well. Consequently, the only thing that remains unclear now is how to test WebSocket.
Unfortunately, WebFlux does not provide an out-of-the-box solution ...
