Test to ensure a coordinated shutdown is successful when a stream involving StreamRefs is running

akka-cluster/src/test/scala/akka/cluster/ClusterSpec.scala

@@ -20,6 +20,8 @@ import com.typesafe.config.ConfigFactory
 import akka.actor.CoordinatedShutdown
 import akka.cluster.ClusterEvent.MemberEvent
 import akka.cluster.ClusterEvent._
+import akka.stream.ActorMaterializer
+import akka.stream.scaladsl.{ Sink, Source, StreamRefs }
 
 import scala.concurrent.Await
 
@@ -171,6 +173,40 @@ class ClusterSpec extends AkkaSpec(ClusterSpec.config) with ImplicitSender {
       }
     }
 
+    "terminate ActorSystem via CoordinatedShutdown.run when a stream involving StreamRefs is running" in {
+      val sys2 = ActorSystem("ClusterSpec2", ConfigFactory.parseString("""
+        akka.actor.provider = "cluster"
+        akka.remote.netty.tcp.port = 0
+        akka.remote.artery.canonical.port = 0
+        akka.coordinated-shutdown.terminate-actor-system = on
+        """))
+      try {
+        val probe = TestProbe()(sys2)
+        Cluster(sys2).subscribe(probe.ref, classOf[MemberEvent])
+        probe.expectMsgType[CurrentClusterState]
+        Cluster(sys2).join(Cluster(sys2).selfAddress)
+        probe.expectMsgType[MemberUp]
+        val mat = ActorMaterializer()(sys2)
+        val sink = Await.result(StreamRefs.sinkRef[String]().to(Sink.ignore).run()(mat), 10.seconds)
+        Source.tick(1.milli, 10.millis, "tick").to(sink).run()(mat)
+
+        CoordinatedShutdown(sys2).run(CoordinatedShutdown.UnknownReason)
+        probe.expectMsgType[MemberLeft]
+        // MemberExited might not be published before MemberRemoved
+        val removed = probe.fishForMessage() {
+          case _: MemberExited  ⇒ false
+          case _: MemberRemoved ⇒ true
+        }.asInstanceOf[MemberRemoved]
+        removed.previousStatus should ===(MemberStatus.Exiting)
+
+        Await.result(sys2.whenTerminated, 10.seconds)
+        Cluster(sys2).isTerminated should ===(true)
+        CoordinatedShutdown(sys2).shutdownReason() should ===(Some(CoordinatedShutdown.UnknownReason))
+      } finally {
+        shutdown(sys2)
+      }
+    }
+
     "leave via CoordinatedShutdown.run when member status is Joining" in {
       val sys2 = ActorSystem("ClusterSpec2", ConfigFactory.parseString("""
         akka.actor.provider = "cluster"