Config customization not respected about blockhound HOT 2 CLOSED

I think that the usual "Mono is asynchronous" caveat applies here: BlockHound can't probably attach the execution phase of the lambda that invokes sleep to the fail() method (which only assembles the Mono without subscribing to it). So what's visible in the stack when the blocking call is attempted is the lamba, the subscribe call and the test method.

In order to allow this particular blocking call, you could use lambda$fail$0 as the method name.

Better yet, I'd advise you to extract that to a relevant method (let's call it example()), replace the lambda with the method's reference and configure BlockHound to allow said method:

@Component
public class BlockHoundDemo {
    
    public void example(Long l) {
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            throw new RuntimeException();
        }
    }

    public Mono<Long> fail() {
        return Mono.delay(Duration.ofSeconds(1)).doOnNext(this::example);
    }
}

and

builder.allowBlockingCallsInside("com.example.demo.BlockHoundDemo", "example");

from blockhound.

@simonbasle Thank you very much for the explanation indeed it works :)

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