NestedPublishers

WARNING

FragileCode

Summary

Avoid Publishers that emit other Publisherss; the resultant code is hard to reason about

Suppression

Suppress false positives by adding the suppression annotation @SuppressWarnings("NestedPublishers") to the enclosing element.

Disable this pattern completely by adding -Xep:NestedPublishers:OFF as compiler argument. Learn more.

Samples

Identification

Shows code lines which will (not) be flagged by this bug pattern.
A //BUG: Diagnostic contains: comment is placed above any violating line.

import org.reactivestreams.Publisher;
import reactor.core.publisher.Flux;
import reactor.core.publisher.GroupedFlux;
import reactor.core.publisher.Mono;

class A {
  void m() {
    Mono.empty();
    Flux.just(1);
    Flux.just(1, 2).groupBy(i -> i).map(groupedFlux -> (GroupedFlux) groupedFlux);

    // BUG: Diagnostic contains:
    Mono.just(Mono.empty());
    // BUG: Diagnostic contains:
    Flux.just(Flux.empty());
    // BUG: Diagnostic contains:
    Mono.just((Flux) Flux.just(1));
    // BUG: Diagnostic contains:
    Flux.just((Publisher) Mono.just(1));
    // BUG: Diagnostic contains:
    Mono.just(1).map(Mono::just);
  }
}