`java:S2201` false negative for primitive-stream cases

SonarQube Server / Community Build
1

Product: SonarQube Community (self-hosted)
sonar-java version: sonar-java 8.28.0.43176 on SonarQube Community Build 26.4.0.121862
Java source level: 21 (javac 21, source/target 17)

Rule

java:S2201 — Return values from functions without side effects should not be ignored

Description

java:S2201 flags ignored Stream#anyMatch results on boxed streams but misses the equivalent calls on primitive streams (IntStream, LongStream, DoubleStream). Since all anyMatch variants are side-effect-free and return a boolean, the primitive-stream cases are false negatives.

Reproducer

import java.util.stream.DoubleStream;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
import java.util.stream.Stream;

public class PrimitiveStreamAnyMatch {

    // Flagged correctly by S2201
    void boxed() {
        Stream<Integer> s = Stream.of(1).filter(i -> i < 5);
        s.anyMatch(i -> i < 5);
    }

    // NOT flagged — should be (false negative)
    void ints() {
        IntStream s = IntStream.of(1).filter(i -> i < 5);
        s.anyMatch(i -> i < 5);
    }

    void longs() {
        LongStream s = LongStream.of(1L).filter(i -> i < 5L);
        s.anyMatch(i -> i < 5L);
    }

    void doubles() {
        DoubleStream s = DoubleStream.of(1.0).filter(i -> i < 5.0);
        s.anyMatch(i -> i < 5.0);
    }
}

Expected behavior

java:S2201 raises an issue on each IntStream/LongStream/DoubleStream#anyMatch call whose boolean result is discarded, identical to the Stream<T>#anyMatch case.

Actual behavior

No issue is reported for the primitive‑stream anyMatch calls; only the Stream<Integer>/Long/Double#anyMatch calls are flagged.

4

Thank you for the thorough report, I verified the issue and converted the thread into a ticket for sonar-java.
You can track its progress here.

Have a nice day!