Zip contains parameter with Mono<Void> type

Reports zip operations that contains arguments with Mono<Void> return value inside a Reactor chain.

Zip completes empty as soon as incoming Mono<Void> completes. The quick-fix suggests replacing zip() and zipWhen() and zipWith() with when.

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

ReactorZipWithMonoVoid

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Reactive Streams | Reactor

Example:

Mono.zip(Mono.just(1), Mono.fromRunnable(() -> System.out.println("value")))
                .map(v -> "New value")
                .doFinally(System.out::println);

After the quick-fix is applied:

Mono.when(Mono.just(1), Mono.fromRunnable(() -> System.out.println("value")))
                .then(Mono.fromCallable(() -> "New value"))
                .doFinally(System.out::println);

New in 2023.1

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection ReactorZipWithMonoVoid

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.2

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025