TestWorkflowEnvironment throws WorkflowExecutionAlreadyCompletedError while executing tests succesfully

[WellingR]

When executing the tests in https://github.com/uber/cadence-java-samples (e.g. HelloAsyncLambdaTest) most of them log an exception even though the test itself succeeds.

It seems that DecisionTask StartToCloseTimeout is being executed even after the workflow is already completed. Why is this task executed at all?

The following stacktrace appears in the test output (for most of the test cases in this samples project)

11:59:54.364 [Timer task] ERROR c.u.c.i.t.TestWorkflowMutableStateImpl - Failure trying to timeout a decision scheduledEventId=1
com.uber.cadence.WorkflowExecutionAlreadyCompletedError: Workflow is already completed: COMPLETED
	at com.uber.cadence.internal.testservice.TestWorkflowMutableStateImpl.checkCompleted(TestWorkflowMutableStateImpl.java:1210)
	at com.uber.cadence.internal.testservice.TestWorkflowMutableStateImpl.update(TestWorkflowMutableStateImpl.java:226)
	at com.uber.cadence.internal.testservice.TestWorkflowMutableStateImpl.completeDecisionUpdate(TestWorkflowMutableStateImpl.java:215)
	at com.uber.cadence.internal.testservice.TestWorkflowMutableStateImpl.timeoutDecisionTask(TestWorkflowMutableStateImpl.java:713)
	at com.uber.cadence.internal.testservice.TestWorkflowMutableStateImpl.lambda$startDecisionTask$0(TestWorkflowMutableStateImpl.java:307)
	at com.uber.cadence.internal.testservice.SelfAdvancingTimerImpl$TimerPump.lambda$runLocked$0(SelfAdvancingTimerImpl.java:99)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:829)

I am running into this issue while implementing tests in my own project, and having these errors in the output is very confusing.