False-positive for java:S2699 "Tests should include assertions"

[ObukhovArtem (Artem Obukhov)]

Environment
SonarLint plugin 4.14.1.27745
InteliJ IDEA 2020.3.2

Problem
S2699 is raised when test gets runnable with assertion from another class in another file.

Example to reproduce with JUnit5
file 1:

class AssertionsInTest {

    @Test
    void compliantTest1() {
        getRunnableWithAssertion();
    }

    @Test
    void compliantTest2() {
        LocalRunnableSupplier.getRunnableWithAssertion();
    }

    @Test
    void compliantTest3() {
        LocalFileRunnableSupplier.getRunnableWithAssertion();
    }

    @Test
    void nonCompliantTest() {
        ExternalRunnableSupplier.getRunnableWithAssertion();
    }

    static Runnable getRunnableWithAssertion() {
        return () -> Assertions.assertTrue(true);
    }

    public static class LocalRunnableSupplier {
        public static Runnable getRunnableWithAssertion() {
            return () -> Assertions.assertTrue(true);
        }
    }

}

class LocalFileRunnableSupplier {
    public static Runnable getRunnableWithAssertion() {
        return () -> Assertions.assertTrue(true);
    }
}

file 2:

public class ExternalRunnableSupplier {
    public static Runnable getRunnableWithAssertion() {
        return () -> Assertions.assertTrue(true);
    }
}

[Margarita_Nedzelska]

Hi Artem,

Thanks for your report and welcome to the community. Unfortunately, in this rule, we’re not performing cross-file analysis and it leads to such FPs. This is a known limitation. A possible workaround could be to name this method from an external file to start with ‘assert’ and the rule will assume a call to that method as an assertion itself.

Regards,
Margarita