AssertionError with MockReset after upgrading from 3.3.2 to 3.3.3

[bahrigencsoy]

After performing the minor upgrade from 3.3.2 to 3.3.3, our "SUBCLASS" mocks started to fail with no obvious reason:

WorkflowElement mock = mock(WorkflowElement.class, withSettings().mockMaker(MockMakers.SUBCLASS));

java.lang.AssertionError: null
    at org.mockito.internal.util.MockUtil.getMockHandlerOrNull(MockUtil.java:160)
    at org.mockito.internal.util.MockUtil.isMock(MockUtil.java:147)
    at org.mockito.internal.util.DefaultMockingDetails.isMock(DefaultMockingDetails.java:32)
    at org.springframework.boot.test.mock.mockito.MockReset.get(MockReset.java:106)
    at org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener.resetMocks(ResetMocksTestExecutionListener.java:85)
    at org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener.resetMocks(ResetMocksTestExecutionListener.java:73)
    at org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener.afterTestMethod(ResetMocksTestExecutionListener.java:67)
    at org.springframework.test.context.TestContextManager.afterTestMethod(TestContextManager.java:487)
    at org.springframework.test.context.junit.jupiter.SpringExtension.afterEach(SpringExtension.java:278)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeAfterEachCallbacks$12(TestMethodTestDescriptor.java:261)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeAllAfterMethodsOrCallbacks$13(TestMethodTestDescriptor.java:277)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeAllAfterMethodsOrCallbacks$14(TestMethodTestDescriptor.java:277)
    at org.junit.platform.commons.util.CollectionUtils.forEachInReverseOrder(CollectionUtils.java:217)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeAllAfterMethodsOrCallbacks(TestMethodTestDescriptor.java:276)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeAfterEachCallbacks(TestMethodTestDescriptor.java:260)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:145)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:69)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:151)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:198)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:169)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:93)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:58)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:141)
    at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:57)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:103)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:85)
    at org.junit.platform.launcher.core.DelegatingLauncher.execute(DelegatingLauncher.java:47)
    at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:63)
    at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:57)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
    at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
    at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
    at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:232)
    at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:55)

The failure is so chaotic that it fails all the tests afterwards. Trying to downgrade bytebuddy version back to 1.14.18 did not solve the problem.

[bahrigencsoy]

Downgrading byte-buddy to 1.14.18 among with slf4j to 2.0.13 seemingly resolves the problem. Neither of them helps individually.

[bahrigencsoy]

Some MockBeans were identified twice, like

@MockBean(classes = {MyService.class}
public class MyTest {
    @MockBean
    MyService myService;
}

I don't know why but removing the class level annotation somehow solved the problem. Apparently it didn't solve the problem.

[philwebb]

@bahrigencsoy Do you have a sample application that reproduces the issue?

[bahrigencsoy]

@bahrigencsoy Do you have a sample application that reproduces the issue?

Unfortunately no, I tried but exposed too much business code, and it was not stable. The IDE/maven/CI behaviors are also inconsistent. I had experienced Mockito tests to fail during debug, but this failure is so chaotic that it breaks all the unit tests after, in the CI.

[philwebb]

I'm afraid we might not be able to do much to help here. We've not really touched the @MockBean code between 3.3.2 and 3.3.3 so all indications point towards a Mockto or Byte-Buddy issue. I would suggest raising an issue with the Mockto team. We're just calling Mockito.mockingDetails(mock).isMock() so I've no idea why that assertion would fail.

[bahrigencsoy]

I know this issue is closed, but for any others for future reference, this problem occurs with a tasteless combination of:

• Subclass mocking
• Mocking a final method
• Final method calling first another mock's external method then own method

(Still no PoC project)

This surely was a poor design, but we only noticed it in this minor upgrade.