The Debug hook discussed in the previous section has a global impact, instrumenting all Flux/Mono instances. Consequently, the impact of the debug hook is application-wide. Alternatively, Reactor also provides a checkpoint operator, which can only alter a particular Flux stream. The checkpoint operator instruments a Reactor Streams after the operator invocation. We can alter our previous test case as follows:
@Testpublic void testPublisherStub() throws Exception { Flux<Long> fibonacciGenerator = getFibonacciGenerator().checkpoint(); StringWriter out = new StringWriter(); new PrintService().printEventNumbers(fibonacciGenerator, new PrintWriter(out)); assertTrue(out.getBuffer().length() >0);}
In the preceding code, ...
