The above test case is failing since the work unit hasn't been completed.
The javax.resource.spi.work.WorkManager#doWork() should be a blocking operation. Likewise there are the scheduleWork() and startWork() methods that needs to be supported.
The implementation is located in org.jboss.resource.work.JBossWorkManager which uses a org.jboss.resource.work.WorkWrapper instance to handle callbacks from the work manager.
The WorkWrapper itself uses org.jboss.util.threadpool.BasicTaskWrapper for its base implementation.
With the replacement of the thread pool implementation to JBoss Thread from org.jboss.util.threadpool.BasicThreadPool the lifecycle of the work unit doesn't comply with the requirements anymore.
This change was committed in rev80054.