powermock: Test failure on JDK11 with PowerMock + JaCoCo offline instrumentation

Steps to reproduce

PowerMock version: JaCoCo version: 0.8.4 Operating system: used this docker image maven:3-jdk-11-slim Tool integration: Maven

Expected behaviour

Complete code coverage equally on different JDK’s

Actual behaviour

Tests breaking on JDK11 and working ok with JDK8

I’ve created a repository to show the problem. I know that the integration between PowerMock and JaCoCo needs to work with offline instrumentation (in some cases) and I’ve created a test project to try it. So I got these results:

• On branch master uses java11 with online instrumentation. The code coverage on DummyService is 15%

• On branch java8 uses java8 with offline instrumentation. The code coverage on DummyService is 100%

• On branch java11 uses java11 with offline instrumentation. The tests are broken with the error bellow:

[ERROR] Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.368 s <<< FAILURE! - in br.com.testing.jacocoerror.service.DummyServiceTest
[ERROR] initializationError(br.com.testing.jacocoerror.service.DummyServiceTest)  Time elapsed: 0.01 s  <<< ERROR!
java.lang.IllegalStateException: Failed to transform class with name br.com.testing.jacocoerror.service.DummyServiceTest. Reason: java.io.IOException: invalid constant type: 17 at 49
Caused by: java.lang.RuntimeException: java.io.IOException: invalid constant type: 17 at 49
Caused by: java.io.IOException: invalid constant type: 17 at 49

I’ve created the same issue inntially on JaCoCo’s repository and as explained there the issue is thrown by PowerMock

https://github.com/powermock/powermock/blob/powermock-2.0.3/powermock-core/src/main/java/org/powermock/core/classloader/javassist/JavassistMockClassLoader.java#L119