4.8.0 RV_EXCEPTION_NOT_THROWN False positive with JUnit 5 assertThrows

[josephearl]

RV | org.junit.jupiter.api.Assertions.assertThrows(Class, Executable) not thrown in com.my.package.SomeServiceTest$someNestedTest.itShouldDoSomething()

Called method org.junit.jupiter.api.Assertions.assertThrows(Class, Executable)
At SomeServiceTest.java:[line 85]

Where line 85 is:

assertThrows(SomeException.class, () -> someService.doSomething("someParam"));

[JuditKnoll]

Can you please provide the someService.doSomething("someParam") function, or at least the header?
I think it got into the code when fixing #2547.

[josephearl]

The method signature is:

public void doSomething(String param)

SomeException is a runtime exception

[bwmeier]

This is flagging just about all of our JUnit tests for exception behavior. It shows up with both org.junit.jupiter.api.Assertions#assertThrows(java.lang.Class<T>, org.junit.jupiter.api.function.Executable) and org.junit.Assert#assertThrows(java.lang.Class<T>, org.junit.function.ThrowingRunnable) invocations, and both Java standard and custom exceptions.

[bwmeier]

As an additional note, I changed one of the tests to use the AssertJ method org.assertj.core.api.Assertions#assertThatExceptionOfType, and the spotbugs failure went away.

[bwmeier]

I think I have a bit more information here. assertThrows returns the exception for further testing by the unit test. If the unit test does nothing with the returned value, then the error is raised by spotbugs. If the unit test does further work with the returned exception value, then the error is not raised. Basically the following code raises the spotbugs error:

Assertions.assertThrows(NullPointerException.class, () -> methodThrowingNpe(null));

but the following code does not:

var npe = Assertions.assertThrows(NullPointerException.class, () -> methodThrowingNpe(null));
Assertions.assertTrue(npe.getMessage().contains("something"));