NPE with retrolambda

Hi I am getting the following exception after upgrading to Kotlin v1.1:

Exception in thread "main" java.lang.NullPointerException
        at org.pitest.mutationtest.filter.KotlinFilter$1.apply(KotlinFilter.java:34)
        at org.pitest.mutationtest.filter.KotlinFilter$1.apply(KotlinFilter.java:31)
        at org.pitest.functional.predicate.Not.apply(Not.java:33)
        at org.pitest.functional.predicate.Not.apply(Not.java:23)
        at org.pitest.functional.FCollection.filter(FCollection.java:84)
        at org.pitest.functional.FCollection.filter(FCollection.java:77)
        at org.pitest.mutationtest.filter.KotlinFilter.filter(KotlinFilter.java:27)
        at org.pitest.mutationtest.filter.CompoundMutationFilter.filter(CompoundMutationFilter.java:22)
        at org.pitest.mutationtest.build.MutationSource.createMutations(MutationSource.java:52)
        at org.pitest.mutationtest.build.MutationTestBuilder$2.apply(MutationTestBuilder.java:100)
        at org.pitest.mutationtest.build.MutationTestBuilder$2.apply(MutationTestBuilder.java:97)
        at org.pitest.functional.FCollection.flatMapTo(FCollection.java:56)
        at org.pitest.functional.FCollection.flatMap(FCollection.java:66)
        at org.pitest.mutationtest.build.MutationTestBuilder.createMutationTestUnits(MutationTestBuilder.java:56)
        at org.pitest.mutationtest.tooling.MutationCoverage.buildMutationTests(MutationCoverage.java:277)
        at org.pitest.mutationtest.tooling.MutationCoverage.runReport(MutationCoverage.java:133)
        at org.pitest.mutationtest.tooling.EntryPoint.execute(EntryPoint.java:103)
        at org.pitest.mutationtest.tooling.EntryPoint.execute(EntryPoint.java:45)
        at org.pitest.mutationtest.commandline.MutationCoverageReport.runReport(MutationCoverageReport.java:87)
        at org.pitest.mutationtest.commandline.MutationCoverageReport.main(MutationCoverageReport.java:45)

I am running it with Gradle: ./gradlew clean pitest

[luontola]

This has been fixed in Retrolambda 2.5.3

[szpak]

Thanks @8armed-monkey for SSCCE. It helped me to reproduce the issue.

First, I was suspecting that Kotlin is somehow leaking into the classpath use but PIT, but it’s not the case:

CP is :pitest-1.2.0.jar:/tmp/sample-npe-pitest-retrolambda/meh/build/classes/test:/tmp/sample-npe-pitest-retrolambda/meh/build/classes/main:rxjava-2.0.6.jar:junit-4.12.jar:mockito-all-1.10.19.jar:hamcrest-all-1.3.jar:reactive-streams-1.0.0.jar:hamcrest-core-1.3.jar

Later on, I realized that you mentioned that the problem occur even in projects which don’t use Kotlin (like that one 😃 ).

The NPE is in the line:

return a.getFilename().toLowerCase().endsWith(“.kt”) && a.getLineNumber() == 0;

which suggests that a filename is null. I debugged that and the ill-fated object is:

MutationDetails [id=MutationIdentifier [location=Location [clazz=test.event.EventBroadcasterImpl$$Lambda$1, method=test, methodDesc=(Ljava/lang/Object;)Z], indexes=[6], mutator=org.pitest.mutationtest.engine.gregor.mutators.ReturnValsMutator], filename=null, block=1, lineNumber=0, description=replaced return of integer sized value with (x == 0 ? 1 : 0), testsInOrder=[]]

The filename is null, but it shouldn’t. The problem may be related to retrolamba.

@8armed-monkey Could you check if the problem occurs also without retrolambda? If not, could you try to use the latest version of retrolambda (2.5.1) to verify that the problem hasn’t been already fixed? If not, it would be good to report it 😃.

@hcoles Maybe it would be good to perform a sanity check of (some) input parameters when MutationDetails is created to be able to fail fast with some more details about the context where MutationDetails was being created?

Btw, just in case, as it may not be documented (yet), to debug PIT in a Gradle build it is enough to set:

pitest {
    mainProcessJvmArgs = ["-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=5005"]
}