Ensure unit test coverage for awaitFailure and exception thrown from render method

[kirillzh]

Consider this simple stateful workflow that throws TODO() on render.

class FooWorkflow : StatefulWorkflow<Unit, State, Unit, Unit>() {

  override fun initialState(
    props: Unit,
    snapshot: Snapshot?
  ): State = State

  override fun render(
    props: Unit,
    state: State,
    context: RenderContext<State, Unit>
  ) {
    TODO("implement me")
  }

  override fun snapshotState(state: State): Snapshot = Snapshot.EMPTY

  object State
}

This is what my unit test looks like to test that the workflow indeed throws (realistically I wanted to throw in a very certain, not yet implemented case and I added a unit test for that ala TDD):

class FooWorkflowTest {
  private val fooWorkflow = FooWorkflow()

  @Test
  fun verifyThrowsException() {
    fooWorkflow.testFromStart {
      assertThat(awaitFailure()).isInstanceOf<NotImplementedError>()
    }
  }
}

While test passes, it still throws right after that:

Exception in thread "main @coroutine#3" kotlin.NotImplementedError: An operation is not implemented: implement
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:20)
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:8)
	at com.squareup.workflow.internal.WorkflowNode.renderWithStateType(WorkflowNode.kt:178)
	at com.squareup.workflow.internal.WorkflowNode.render(WorkflowNode.kt:95)
	at com.squareup.workflow.internal.RealWorkflowLoop$runWorkflowLoop$2.invokeSuspend(WorkflowLoop.kt:79)
	(Coroutine boundary)
	at com.squareup.workflow.LaunchWorkflowKt$launchWorkflowImpl$workflowJob$1.invokeSuspend(LaunchWorkflow.kt:174)
Caused by: kotlin.NotImplementedError: An operation is not implemented: implement
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:20)
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:8)
	at com.squareup.workflow.internal.WorkflowNode.renderWithStateType(WorkflowNode.kt:178)
	at com.squareup.workflow.internal.WorkflowNode.render(WorkflowNode.kt:95)
	at com.squareup.workflow.internal.RealWorkflowLoop$runWorkflowLoop$2.invokeSuspend(WorkflowLoop.kt:79)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(Dispatched.kt:241)
	at kotlinx.coroutines.EventLoop.processUnconfinedEvent(EventLoop.common.kt:68)
	at kotlinx.coroutines.DispatchedKt.resumeCancellable(Dispatched.kt:464)
	at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:26)
	at kotlinx.coroutines.CoroutineStart.invoke(CoroutineStart.kt:109)
	at kotlinx.coroutines.AbstractCoroutine.start(AbstractCoroutine.kt:154)
	at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch(Builders.common.kt:54)
	at kotlinx.coroutines.BuildersKt.launch(Unknown Source)
	at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch$default(Builders.common.kt:47)
	at kotlinx.coroutines.BuildersKt.launch$default(Unknown Source)
	at com.squareup.workflow.LaunchWorkflowKt.launchWorkflowImpl(LaunchWorkflow.kt:166)
	at com.squareup.workflow.LaunchWorkflowKt.launchWorkflowIn(LaunchWorkflow.kt:109)
	at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart(WorkflowTester.kt:230)
	at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart(WorkflowTester.kt:253)
	at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart$default(WorkflowTester.kt:251)
	at com.squareup.scales.FooWorkflowTest.verifyThrowsException(FooWorkflowTest.kt:13)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:305)
	at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:365)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
	at org.junit.runners.ParentRunner$4.run(ParentRunner.java:330)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:78)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:328)
	at org.junit.runners.ParentRunner.access$100(ParentRunner.java:65)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:292)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:305)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:412)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.rt.execution.CommandLineWrapper.main(CommandLineWrapper.java:66)
Exception in thread "main @coroutine#1" kotlin.NotImplementedError: An operation is not implemented: implement
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:20)
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:8)
	at com.squareup.workflow.internal.WorkflowNode.renderWithStateType(WorkflowNode.kt:178)
	at com.squareup.workflow.internal.WorkflowNode.render(WorkflowNode.kt:95)
	at com.squareup.workflow.internal.RealWorkflowLoop$runWorkflowLoop$2.invokeSuspend(WorkflowLoop.kt:79)
	(Coroutine boundary)
	at com.squareup.workflow.LaunchWorkflowKt$launchWorkflowImpl$workflowJob$1.invokeSuspend(LaunchWorkflow.kt:174)
Caused by: kotlin.NotImplementedError: An operation is not implemented: implement
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:20)
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:8)
	at com.squareup.workflow.internal.WorkflowNode.renderWithStateType(WorkflowNode.kt:178)
	at com.squareup.workflow.internal.WorkflowNode.render(WorkflowNode.kt:95)
	at com.squareup.workflow.internal.RealWorkflowLoop$runWorkflowLoop$2.invokeSuspend(WorkflowLoop.kt:79)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(Dispatched.kt:241)
	at kotlinx.coroutines.EventLoop.processUnconfinedEvent(EventLoop.common.kt:68)
	at kotlinx.coroutines.DispatchedKt.resumeCancellable(Dispatched.kt:464)
	at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:26)
	at kotlinx.coroutines.CoroutineStart.invoke(CoroutineStart.kt:109)
	at kotlinx.coroutines.AbstractCoroutine.start(AbstractCoroutine.kt:154)
	at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch(Builders.common.kt:54)
	at kotlinx.coroutines.BuildersKt.launch(Unknown Source)
	at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch$default(Builders.common.kt:47)
	at kotlinx.coroutines.BuildersKt.launch$default(Unknown Source)
	at com.squareup.workflow.LaunchWorkflowKt.launchWorkflowImpl(LaunchWorkflow.kt:166)
	at com.squareup.workflow.LaunchWorkflowKt.launchWorkflowIn(LaunchWorkflow.kt:109)
	at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart(WorkflowTester.kt:230)
	at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart(WorkflowTester.kt:253)
	at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart$default(WorkflowTester.kt:251)
	at com.squareup.scales.FooWorkflowTest.verifyThrowsException(FooWorkflowTest.kt:13)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:305)
	at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:365)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
	at org.junit.runners.ParentRunner$4.run(ParentRunner.java:330)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:78)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:328)
	at org.junit.runners.ParentRunner.access$100(ParentRunner.java:65)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:292)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:305)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:412)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.rt.execution.CommandLineWrapper.main(CommandLineWrapper.java:66)
Exception in thread "main @coroutine#2" kotlin.NotImplementedError: An operation is not implemented: implement
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:20)
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:8)
	at com.squareup.workflow.internal.WorkflowNode.renderWithStateType(WorkflowNode.kt:178)
	at com.squareup.workflow.internal.WorkflowNode.render(WorkflowNode.kt:95)
	at com.squareup.workflow.internal.RealWorkflowLoop$runWorkflowLoop$2.invokeSuspend(WorkflowLoop.kt:79)
	(Coroutine boundary)
	at com.squareup.workflow.LaunchWorkflowKt$launchWorkflowImpl$workflowJob$1.invokeSuspend(LaunchWorkflow.kt:174)
Caused by: kotlin.NotImplementedError: An operation is not implemented: implement
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:20)
	at com.squareup.scales.FooWorkflow.render(FooWorkflow.kt:8)
	at com.squareup.workflow.internal.WorkflowNode.renderWithStateType(WorkflowNode.kt:178)
	at com.squareup.workflow.internal.WorkflowNode.render(WorkflowNode.kt:95)
	at com.squareup.workflow.internal.RealWorkflowLoop$runWorkflowLoop$2.invokeSuspend(WorkflowLoop.kt:79)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(Dispatched.kt:241)
	at kotlinx.coroutines.EventLoop.processUnconfinedEvent(EventLoop.common.kt:68)
	at kotlinx.coroutines.DispatchedKt.resumeCancellable(Dispatched.kt:464)
	at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:26)
	at kotlinx.coroutines.CoroutineStart.invoke(CoroutineStart.kt:109)
	at kotlinx.coroutines.AbstractCoroutine.start(AbstractCoroutine.kt:154)
	at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch(Builders.common.kt:54)
	at kotlinx.coroutines.BuildersKt.launch(Unknown Source)
	at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch$default(Builders.common.kt:47)
	at kotlinx.coroutines.BuildersKt.launch$default(Unknown Source)
	at com.squareup.workflow.LaunchWorkflowKt.launchWorkflowImpl(LaunchWorkflow.kt:166)
	at com.squareup.workflow.LaunchWorkflowKt.launchWorkflowIn(LaunchWorkflow.kt:109)
	at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart(WorkflowTester.kt:230)
	at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart(WorkflowTester.kt:253)
	at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart$default(WorkflowTester.kt:251)
	at com.squareup.scales.FooWorkflowTest.verifyThrowsException(FooWorkflowTest.kt:13)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:59)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:56)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:305)
	at org.junit.runners.BlockJUnit4ClassRunner$1.evaluate(BlockJUnit4ClassRunner.java:100)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:365)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:103)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:63)
	at org.junit.runners.ParentRunner$4.run(ParentRunner.java:330)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:78)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:328)
	at org.junit.runners.ParentRunner.access$100(ParentRunner.java:65)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:292)
	at org.junit.runners.ParentRunner$3.evaluate(ParentRunner.java:305)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:412)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at com.intellij.rt.execution.CommandLineWrapper.main(CommandLineWrapper.java:66)

[kirillzh]

Actually, tried substituting test verification with waiting for next rendering and then catching the exception but it seems to throw multiple times as well:

fooWorkflow.testFromStart {
  assertFailsWith<NotImplementedError> {
      awaitNextRendering()
  }
}

[zach-klippenstein]

The test shouldn't pass if it gets thrown outside the test method though - is it just getting printed?

[kirillzh]

So it seems that IDE marks the test as passed but shows the stacktrace for the exception anyway, while running from CLI just marks the test as failed with same stacktrace.

[zach-klippenstein]

running from CLI just marks the test as failed with same stacktrace

@kirillzh What is the output from CLI? I'm not seeing that test fail in IDE or CLI, with either assertion.

As for the stacktrace getting printed, that's expected behavior. The exception isn't getting thrown, it's just being reported by coroutine machinery.

[kirillzh]

@zach-klippenstein, here's full CLI stack trace:

com.squareup.foo.FooWorkflowTest > verifyThrowsException STANDARD_ERROR
    [RethrowingExceptionHandler] uncaught exception: kotlin.NotImplementedError: An operation is not implemented: implement me
    [RethrowingExceptionHandler] uncaught exception: kotlinx.coroutines.CoroutinesInternalError: Fatal exception in coroutines machinery for DispatchedContinuation[Unconfined, Continuation at com.squareup.workflow.LaunchWorkflowKt$launchWorkflowImpl$workflowJob$1.invokeSuspend(LaunchWorkflow.kt:174)@3138c899]. Please read KDoc to 'handleFatalException' method and report this incident to maintainers
    [RethrowingExceptionHandler] uncaught exception: kotlinx.coroutines.CoroutinesInternalError: Fatal exception in coroutines machinery for DispatchedContinuation[Unconfined, Continuation at com.squareup.workflow.LaunchWorkflowKt$launchWorkflowImpl$workflowJob$1.invokeSuspend(LaunchWorkflow.kt:174)@3138c899]. Please read KDoc to 'handleFatalException' method and report this incident to maintainers

com.squareup.foo.FooWorkflowTest > verifyThrowsException FAILED
    java.lang.IllegalStateException: Job "coroutine#3":StandaloneCoroutine{Cancelling}@5318da4a is already complete or completing, but is being completed with CompletedExceptionally[com.squareup.testing.listener.UncaughtException:

        The uncaught exception handler was called during a unit test. This test failure might not be
        reproducible with Buck or in the IDE. It's recommended to reproduce the failure with Gradle,
        e.g.    ./gradlew :your:module:testDebugUnitTest

        ]
        at kotlinx.coroutines.JobSupport.makeCompletingOnce$kotlinx_coroutines_core(JobSupport.kt:788)
        at kotlinx.coroutines.AbstractCoroutine.resumeWith(AbstractCoroutine.kt:111)
        at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:52)
        at kotlinx.coroutines.CoroutineStart.invoke(CoroutineStart.kt:109)
        at kotlinx.coroutines.AbstractCoroutine.start(AbstractCoroutine.kt:154)
        at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch(Builders.common.kt:54)
        at kotlinx.coroutines.BuildersKt.launch(Unknown Source)
        at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch$default(Builders.common.kt:47)
        at kotlinx.coroutines.BuildersKt.launch$default(Unknown Source)
        at com.squareup.workflow.LaunchWorkflowKt.launchWorkflowImpl(LaunchWorkflow.kt:166)
        at com.squareup.workflow.LaunchWorkflowKt.launchWorkflowIn(LaunchWorkflow.kt:109)
        at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart(WorkflowTester.kt:230)
        at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart(WorkflowTester.kt:253)
        at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart$default(WorkflowTester.kt:251)
        at com.squareup.foo.FooWorkflowTest.verifyThrowsException(FooWorkflowTest.kt:17)

        Caused by:
        com.squareup.testing.listener.UncaughtException:

            The uncaught exception handler was called during a unit test. This test failure might not be
            reproducible with Buck or in the IDE. It's recommended to reproduce the failure with Gradle,
            e.g.    ./gradlew :your:module:testDebugUnitTest


            at com.squareup.testing.listener.RethrowingExceptionHandler.uncaughtException(RethrowingExceptionHandler.kt:46)
            at com.squareup.testing.listener.RethrowingExceptionHandler.uncaughtException(RethrowingExceptionHandler.kt:7)
            at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1057)
            at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1052)
            at kotlinx.coroutines.CoroutineExceptionHandlerImplKt.handleCoroutineExceptionImpl(CoroutineExceptionHandlerImpl.kt:40)
            at kotlinx.coroutines.CoroutineExceptionHandlerKt.handleCoroutineException(CoroutineExceptionHandler.kt:33)
            at kotlinx.coroutines.DispatchedTask.handleFatalException$kotlinx_coroutines_core(Dispatched.kt:280)
            at kotlinx.coroutines.DispatchedKt.resumeCancellable(Dispatched.kt:480)
            at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:26)
            ... 12 more

            Caused by:
            kotlinx.coroutines.CoroutinesInternalError: Fatal exception in coroutines machinery for DispatchedContinuation[Unconfined, Continuation at com.squareup.workflow.LaunchWorkflowKt$launchWorkflowImpl$workflowJob$1.invokeSuspend(LaunchWorkflow.kt:174)@3138c899]. Please read KDoc to 'handleFatalException' method and report this incident to maintainers
                at kotlinx.coroutines.DispatchedTask.handleFatalException$kotlinx_coroutines_core(Dispatched.kt:278)
                ... 14 more

                Caused by:
                com.squareup.testing.listener.UncaughtException:

                    The uncaught exception handler was called during a unit test. This test failure might not be
                    reproducible with Buck or in the IDE. It's recommended to reproduce the failure with Gradle,
                    e.g.    ./gradlew :your:module:testDebugUnitTest


                    at com.squareup.testing.listener.RethrowingExceptionHandler.uncaughtException(RethrowingExceptionHandler.kt:46)
                    at com.squareup.testing.listener.RethrowingExceptionHandler.uncaughtException(RethrowingExceptionHandler.kt:7)
                    at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1057)
                    at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1052)
                    at kotlinx.coroutines.CoroutineExceptionHandlerImplKt.handleCoroutineExceptionImpl(CoroutineExceptionHandlerImpl.kt:40)
                    at kotlinx.coroutines.CoroutineExceptionHandlerKt.handleCoroutineException(CoroutineExceptionHandler.kt:33)
                    at kotlinx.coroutines.DispatchedTask.handleFatalException$kotlinx_coroutines_core(Dispatched.kt:280)
                    at kotlinx.coroutines.DispatchedTask.run(Dispatched.kt:249)
                    at kotlinx.coroutines.EventLoop.processUnconfinedEvent(EventLoop.common.kt:68)
                    at kotlinx.coroutines.DispatchedKt.resumeCancellable(Dispatched.kt:464)
                    ... 13 more

                    Caused by:
                    kotlinx.coroutines.CoroutinesInternalError: Fatal exception in coroutines machinery for DispatchedContinuation[Unconfined, Continuation at com.squareup.workflow.LaunchWorkflowKt$launchWorkflowImpl$workflowJob$1.invokeSuspend(LaunchWorkflow.kt:174)@3138c899]. Please read KDoc to 'handleFatalException' method and report this incident to maintainers
                        at kotlinx.coroutines.DispatchedTask.handleFatalException$kotlinx_coroutines_core(Dispatched.kt:278)
                        ... 16 more

                        Caused by:
                        com.squareup.testing.listener.UncaughtException:

                            The uncaught exception handler was called during a unit test. This test failure might not be
                            reproducible with Buck or in the IDE. It's recommended to reproduce the failure with Gradle,
                            e.g.    ./gradlew :your:module:testDebugUnitTest


                            at com.squareup.testing.listener.RethrowingExceptionHandler.uncaughtException(RethrowingExceptionHandler.kt:46)
                            at com.squareup.testing.listener.RethrowingExceptionHandler.uncaughtException(RethrowingExceptionHandler.kt:7)
                            at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1057)
                            at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1052)
                            at kotlinx.coroutines.CoroutineExceptionHandlerImplKt.handleCoroutineExceptionImpl(CoroutineExceptionHandlerImpl.kt:40)
                            at kotlinx.coroutines.CoroutineExceptionHandlerKt.handleCoroutineException(CoroutineExceptionHandler.kt:33)
                            at kotlinx.coroutines.StandaloneCoroutine.handleJobException(Builders.common.kt:184)
                            at kotlinx.coroutines.JobSupport.tryFinalizeFinishingState(JobSupport.kt:226)
                            at kotlinx.coroutines.JobSupport.tryMakeCompletingSlowPath(JobSupport.kt:849)
                            at kotlinx.coroutines.JobSupport.tryMakeCompleting(JobSupport.kt:811)
                            at kotlinx.coroutines.JobSupport.makeCompletingOnce$kotlinx_coroutines_core(JobSupport.kt:787)
                            at kotlinx.coroutines.AbstractCoroutine.resumeWith(AbstractCoroutine.kt:111)
                            at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:46)
                            at kotlinx.coroutines.DispatchedTask.run(Dispatched.kt:334)
                            ... 15 more

                            Caused by:
                            kotlin.NotImplementedError: An operation is not implemented: implement me

                                Caused by:
                                kotlin.NotImplementedError: An operation is not implemented: implement me
                                    at com.squareup.foo.FooWorkflow.render(FooWorkflowTest.kt:35)
                                    at com.squareup.foo.FooWorkflow.render(FooWorkflowTest.kt:23)
                                    at com.squareup.workflow.internal.WorkflowNode.renderWithStateType(WorkflowNode.kt:178)
                                    at com.squareup.workflow.internal.WorkflowNode.render(WorkflowNode.kt:95)
                                    at com.squareup.workflow.internal.RealWorkflowLoop$runWorkflowLoop$2.invokeSuspend(WorkflowLoop.kt:79)
                                    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
                                    at kotlinx.coroutines.DispatchedTask.run(Dispatched.kt:241)
                                    at kotlinx.coroutines.EventLoop.processUnconfinedEvent(EventLoop.common.kt:68)
                                    at kotlinx.coroutines.DispatchedKt.resumeCancellable(Dispatched.kt:464)
                                    at kotlinx.coroutines.intrinsics.CancellableKt.startCoroutineCancellable(Cancellable.kt:26)
                                    at kotlinx.coroutines.CoroutineStart.invoke(CoroutineStart.kt:109)
                                    at kotlinx.coroutines.AbstractCoroutine.start(AbstractCoroutine.kt:154)
                                    at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch(Builders.common.kt:54)
                                    at kotlinx.coroutines.BuildersKt.launch(Unknown Source)
                                    at kotlinx.coroutines.BuildersKt__Builders_commonKt.launch$default(Builders.common.kt:47)
                                    at kotlinx.coroutines.BuildersKt.launch$default(Unknown Source)
                                    at com.squareup.workflow.LaunchWorkflowKt.launchWorkflowImpl(LaunchWorkflow.kt:166)
                                    at com.squareup.workflow.LaunchWorkflowKt.launchWorkflowIn(LaunchWorkflow.kt:109)
                                    at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart(WorkflowTester.kt:230)
                                    at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart(WorkflowTester.kt:253)
                                    at com.squareup.workflow.testing.WorkflowTesterKt.testFromStart$default(WorkflowTester.kt:251)
                                    at com.squareup.foo.FooWorkflowTest.verifyThrowsException(FooWorkflowTest.kt:17)
3 exceptions were reported to the default uncaught exception handler:
com.squareup.foo.FooWorkflowTest:
        verifyThrowsException @ FooWorkflowTest.kt:17

6 tests completed, 1 failed, 5 skipped

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':features:foo:impl:testDebugUnitTest'.
> Process 'Gradle Test Executor 4' finished with non-zero exit value 1
  This problem might be caused by incorrect test process configuration.
  Please refer to the test execution section in the User Manual at https://docs.gradle.org/5.6.2/userguide/java_testing.html#sec:test_execution

* Try:
Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':features:foo:impl:testDebugUnitTest'.
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$3.accept(ExecuteActionsTaskExecuter.java:166)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$3.accept(ExecuteActionsTaskExecuter.java:163)
        at org.gradle.internal.Try$Failure.ifSuccessfulOrElse(Try.java:191)
        at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:156)
        at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:62)
        at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:108)
        at org.gradle.api.internal.tasks.execution.ResolveBeforeExecutionOutputsTaskExecuter.execute(ResolveBeforeExecutionOutputsTaskExecuter.java:67)
        at org.gradle.api.internal.tasks.execution.StartSnapshotTaskInputsBuildOperationTaskExecuter.execute(StartSnapshotTaskInputsBuildOperationTaskExecuter.java:62)
        at org.gradle.api.internal.tasks.execution.ResolveAfterPreviousExecutionStateTaskExecuter.execute(ResolveAfterPreviousExecutionStateTaskExecuter.java:46)
        at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:94)
        at org.gradle.api.internal.tasks.execution.FinalizePropertiesTaskExecuter.execute(FinalizePropertiesTaskExecuter.java:46)
        at org.gradle.api.internal.tasks.execution.ResolveTaskExecutionModeExecuter.execute(ResolveTaskExecutionModeExecuter.java:95)
        at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:57)
        at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:56)
        at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:36)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.executeTask(EventFiringTaskExecuter.java:77)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:55)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.call(EventFiringTaskExecuter.java:52)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102)
        at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
        at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:52)
        at org.gradle.execution.plan.LocalTaskNodeExecutor.execute(LocalTaskNodeExecutor.java:43)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:355)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$InvokeNodeExecutorsAction.execute(DefaultTaskExecutionGraph.java:343)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:336)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareExecutionAction.execute(DefaultTaskExecutionGraph.java:322)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:134)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker$1.execute(DefaultPlanExecutor.java:129)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.execute(DefaultPlanExecutor.java:202)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.executeNextNode(DefaultPlanExecutor.java:193)
        at org.gradle.execution.plan.DefaultPlanExecutor$ExecutorWorker.run(DefaultPlanExecutor.java:129)
        at org.gradle.execution.plan.DefaultPlanExecutor.process(DefaultPlanExecutor.java:74)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph.executeWithServices(DefaultTaskExecutionGraph.java:178)
        at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph.execute(DefaultTaskExecutionGraph.java:154)
        at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTaskExecutionAction.java:41)
        at org.gradle.execution.DefaultBuildWorkExecutor.execute(DefaultBuildWorkExecutor.java:40)
        at org.gradle.execution.DefaultBuildWorkExecutor.access$000(DefaultBuildWorkExecutor.java:24)
        at org.gradle.execution.DefaultBuildWorkExecutor$1.proceed(DefaultBuildWorkExecutor.java:48)
        at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildExecutionAction.java:49)
        at org.gradle.execution.DefaultBuildWorkExecutor.execute(DefaultBuildWorkExecutor.java:40)
        at org.gradle.execution.DefaultBuildWorkExecutor.execute(DefaultBuildWorkExecutor.java:33)
        at org.gradle.execution.IncludedBuildLifecycleBuildWorkExecutor.execute(IncludedBuildLifecycleBuildWorkExecutor.java:36)
        at org.gradle.execution.BuildOperationFiringBuildWorkerExecutor$ExecuteTasks.run(BuildOperationFiringBuildWorkerExecutor.java:56)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:402)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:394)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:92)
        at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
        at org.gradle.execution.BuildOperationFiringBuildWorkerExecutor.execute(BuildOperationFiringBuildWorkerExecutor.java:41)
        at org.gradle.initialization.DefaultGradleLauncher.runWork(DefaultGradleLauncher.java:236)
        at org.gradle.initialization.DefaultGradleLauncher.doClassicBuildStages(DefaultGradleLauncher.java:147)
        at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:126)
        at org.gradle.initialization.DefaultGradleLauncher.executeTasks(DefaultGradleLauncher.java:106)
        at org.gradle.internal.invocation.GradleBuildController$1.execute(GradleBuildController.java:60)
        at org.gradle.internal.invocation.GradleBuildController$1.execute(GradleBuildController.java:57)
        at org.gradle.internal.invocation.GradleBuildController$3.create(GradleBuildController.java:85)
        at org.gradle.internal.invocation.GradleBuildController$3.create(GradleBuildController.java:78)
        at org.gradle.internal.work.DefaultWorkerLeaseService.withLocks(DefaultWorkerLeaseService.java:189)
        at org.gradle.internal.work.StopShieldingWorkerLeaseService.withLocks(StopShieldingWorkerLeaseService.java:40)
        at org.gradle.internal.invocation.GradleBuildController.doBuild(GradleBuildController.java:78)
        at org.gradle.internal.invocation.GradleBuildController.run(GradleBuildController.java:57)
        at org.gradle.tooling.internal.provider.ExecuteBuildActionRunner.run(ExecuteBuildActionRunner.java:31)
        at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35)
        at org.gradle.launcher.exec.BuildOutcomeReportingBuildActionRunner.run(BuildOutcomeReportingBuildActionRunner.java:63)
        at org.gradle.tooling.internal.provider.ValidatingBuildActionRunner.run(ValidatingBuildActionRunner.java:32)
        at org.gradle.launcher.exec.BuildCompletionNotifyingBuildActionRunner.run(BuildCompletionNotifyingBuildActionRunner.java:39)
        at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner$3.call(RunAsBuildOperationBuildActionRunner.java:51)
        at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner$3.call(RunAsBuildOperationBuildActionRunner.java:45)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:416)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$CallableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:406)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor$1.execute(DefaultBuildOperationExecutor.java:165)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:250)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:158)
        at org.gradle.internal.operations.DefaultBuildOperationExecutor.call(DefaultBuildOperationExecutor.java:102)
        at org.gradle.internal.operations.DelegatingBuildOperationExecutor.call(DelegatingBuildOperationExecutor.java:36)
        at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner.run(RunAsBuildOperationBuildActionRunner.java:45)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter$1.transform(InProcessBuildActionExecuter.java:50)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter$1.transform(InProcessBuildActionExecuter.java:47)
        at org.gradle.composite.internal.DefaultRootBuildState.run(DefaultRootBuildState.java:78)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:47)
        at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:31)
        at org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:42)
        at org.gradle.launcher.exec.BuildTreeScopeBuildActionExecuter.execute(BuildTreeScopeBuildActionExecuter.java:28)
        at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:78)
        at org.gradle.tooling.internal.provider.ContinuousBuildActionExecuter.execute(ContinuousBuildActionExecuter.java:52)
        at org.gradle.tooling.internal.provider.SubscribableBuildActionExecuter.execute(SubscribableBuildActionExecuter.java:59)
        at org.gradle.tooling.internal.provider.SubscribableBuildActionExecuter.execute(SubscribableBuildActionExecuter.java:36)
        at org.gradle.tooling.internal.provider.SessionScopeBuildActionExecuter.execute(SessionScopeBuildActionExecuter.java:68)
        at org.gradle.tooling.internal.provider.SessionScopeBuildActionExecuter.execute(SessionScopeBuildActionExecuter.java:38)
        at org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:37)
        at org.gradle.tooling.internal.provider.GradleThreadBuildActionExecuter.execute(GradleThreadBuildActionExecuter.java:26)
        at org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:43)
        at org.gradle.tooling.internal.provider.ParallelismConfigurationBuildActionExecuter.execute(ParallelismConfigurationBuildActionExecuter.java:29)
        at org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:60)
        at org.gradle.tooling.internal.provider.StartParamsValidatingActionExecuter.execute(StartParamsValidatingActionExecuter.java:32)
        at org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:55)
        at org.gradle.tooling.internal.provider.SessionFailureReportingActionExecuter.execute(SessionFailureReportingActionExecuter.java:41)
        at org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:48)
        at org.gradle.tooling.internal.provider.SetupLoggingActionExecuter.execute(SetupLoggingActionExecuter.java:32)
        at org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:68)
        at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:37)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
        at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:39)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
        at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:27)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
        at org.gradle.launcher.daemon.server.exec.RequestStopIfSingleUsedDaemon.execute(RequestStopIfSingleUsedDaemon.java:35)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
        at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.create(ForwardClientInput.java:78)
        at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.create(ForwardClientInput.java:75)
        at org.gradle.util.Swapper.swap(Swapper.java:38)
        at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:75)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
        at org.gradle.launcher.daemon.server.exec.LogAndCheckHealth.execute(LogAndCheckHealth.java:55)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
        at org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:63)
        at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:37)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
        at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:82)
        at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:37)
        at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:104)
        at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy$1.run(StartBuildOrRespondWithBusy.java:52)
        at org.gradle.launcher.daemon.server.DaemonStateCoordinator$1.run(DaemonStateCoordinator.java:297)
        at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
        at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
        at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
Caused by: org.gradle.process.internal.ExecException: Process 'Gradle Test Executor 4' finished with non-zero exit value 1
This problem might be caused by incorrect test process configuration.
Please refer to the test execution section in the User Manual at https://docs.gradle.org/5.6.2/userguide/java_testing.html#sec:test_execution
        at org.gradle.api.internal.tasks.testing.worker.ForkingTestClassProcessor.stop(ForkingTestClassProcessor.java:166)
        at org.gradle.api.internal.tasks.testing.processors.RestartEveryNTestClassProcessor.endBatch(RestartEveryNTestClassProcessor.java:77)
        at org.gradle.api.internal.tasks.testing.processors.RestartEveryNTestClassProcessor.stop(RestartEveryNTestClassProcessor.java:62)
        at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
        at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
        at org.gradle.internal.dispatch.FailureHandlingDispatch.dispatch(FailureHandlingDispatch.java:30)
        at org.gradle.internal.dispatch.AsyncDispatch.dispatchMessages(AsyncDispatch.java:87)
        at org.gradle.internal.dispatch.AsyncDispatch.access$000(AsyncDispatch.java:36)
        at org.gradle.internal.dispatch.AsyncDispatch$1.run(AsyncDispatch.java:71)
        at org.gradle.internal.concurrent.InterruptibleRunnable.run(InterruptibleRunnable.java:42)
        at org.gradle.internal.operations.CurrentBuildOperationPreservingRunnable.run(CurrentBuildOperationPreservingRunnable.java:42)
        ... 3 more

[zach-klippenstein]

Ah, it's bubbling up to the thread's uncaught exception handler. That seems like a bug.