Method Only.verify throws NullPointerException

[ilia-sretenskii]

Method Only.verify throws NullPointerException with the latest mockito-core 5.9.0

Here is a sample code in Kotlin which triggers this issue.

verify(service, only()).doSomething()

It triggers the following NullPointerException to be thrown.

java.lang.NullPointerException: Cannot invoke "org.mockito.invocation.Invocation.getMock()" because "undesired" is null
	at org.mockito.internal.exceptions.Reporter.noMoreInteractionsWanted(Reporter.java:555)
	at org.mockito.internal.verification.Only.verify(Only.java:30)
	at org.mockito.internal.verification.MockAwareVerificationMode.verify(MockAwareVerificationMode.java:30)
	at org.mockito.internal.handler.MockHandlerImpl.handle(MockHandlerImpl.java:75)
	at org.mockito.internal.handler.NullResultGuardian.handle(NullResultGuardian.java:29)
	at org.mockito.internal.handler.InvocationNotifierHandler.handle(InvocationNotifierHandler.java:34)
	at org.mockito.internal.creation.bytebuddy.MockMethodInterceptor.doIntercept(MockMethodInterceptor.java:82)
	at org.mockito.internal.creation.bytebuddy.MockMethodAdvice.handle(MockMethodAdvice.java:134)

A quick analysis shows that it is caused by method Only.verify which searches for an optional unverified invocation by execution of method InvocationsFinder.findFirstUnverified, but then fails to check for the result for null and just calls method Reporter.noMoreInteractionsWanted which throws the exception because the invocation was not found.
https://github.com/mockito/mockito/blob/main/src/main/java/org/mockito/internal/verification/Only.java#L29C37-L30

        MatchableInvocation target = data.getTarget();
        List<Invocation> invocations = data.getAllInvocations();
        List<Invocation> chunk = findInvocations(invocations, target);
        if (invocations.size() != 1 && !chunk.isEmpty()) {
            Invocation unverified = findFirstUnverified(invocations);
            throw noMoreInteractionsWanted(unverified, (List) invocations);
        }

Note that there is method NoMoreInteractions.verify which also makes a call to the same two methods InvocationsFinder.findFirstUnverified and Reporter.noMoreInteractionsWanted but it does so properly, thus the exception can not be thrown there.
https://github.com/mockito/mockito/blob/main/src/main/java/org/mockito/internal/verification/NoMoreInteractions.java#L25-L28

        Invocation unverified = findFirstUnverified(data.getAllInvocations());
        if (unverified != null) {
            throw noMoreInteractionsWanted(unverified, (List) data.getAllInvocations());
        }

So I suggest that the same check for null would be made in method Only.verify to avoid the exception.
And I also suggest that static analysis based on annotations would be introduced, then it would be obvious that method findFirstUnverified returns a nullable value while method noMoreInteractionsWanted does not accept a nullable argument.

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