Compile akka-cluster-metrics on scala3 (#30690)

* Compile akka-cluster-metrics on scala3

* re-introduce serialversionuid

* Avoid weird patternmatch

.github/workflows/scala3-build.yml

@@ -22,7 +22,7 @@ jobs:
           - akka-testkit/test akka-actor-tests/test
           - akka-actor-testkit-typed/test akka-actor-typed-tests/test
           - akka-bench-jmh/test
-          - akka-cluster/Test/compile akka-cluster-tools/test akka-distributed-data/test
+          - akka-cluster/Test/compile akka-cluster-tools/test akka-distributed-data/test akka-cluster-metrics/Test/compile
           - akka-coordination/test
           - akka-discovery/test
           - akka-persistence/test akka-persistence-shared/test akka-persistence-query/test

akka-cluster-metrics/src/main/scala/akka/cluster/metrics/ClusterMetricsExtension.scala

@@ -52,7 +52,7 @@ class ClusterMetricsExtension(system: ExtendedActorSystem) extends Extension {
       SupervisorStrategyProvider,
       immutable.Seq(classOf[Config] -> SupervisorStrategyConfiguration))
     .getOrElse {
-      val log: LoggingAdapter = Logging(system, getClass)
+      val log: LoggingAdapter = Logging(system, classOf[ClusterMetricsExtension])
       log.error(s"Configured strategy provider ${SupervisorStrategyProvider} failed to load, using default ${classOf[
         ClusterMetricsStrategy].getName}.")
       new ClusterMetricsStrategy(SupervisorStrategyConfiguration)

akka-cluster-metrics/src/main/scala/akka/cluster/metrics/ClusterMetricsRouting.scala

@@ -420,7 +420,7 @@ object MetricsSelector {
 /**
  * A MetricsSelector is responsible for producing weights from the node metrics.
  */
-@nowarn("msg=@SerialVersionUID has no effect")
+@nowarn("msg=@SerialVersionUID")
 @SerialVersionUID(1L)
 trait MetricsSelector extends Serializable {
 

akka-cluster-metrics/src/test/scala/akka/cluster/metrics/MetricSpec.scala

@@ -280,6 +280,8 @@ class MetricValuesSpec extends AkkaSpec(MetricsConfig.defaultEnabled) with Metri
             // we don't check the heap max value in this test.
             // extract is the java api
             StandardMetrics.extractHeapMemory(node) should not be null
+          case other =>
+            fail(other.toString)
         }
 
         node match {
@@ -297,6 +299,8 @@ class MetricValuesSpec extends AkkaSpec(MetricsConfig.defaultEnabled) with Metri
             }
             // extract is the java api
             StandardMetrics.extractCpu(node) should not be null
+          case other =>
+            fail(other.toString)
         }
       }
     }

akka-remote/src/test/scala/akka/remote/Ticket1978CommunicationSpec.scala

@@ -72,10 +72,9 @@ object Configuration {
       provider: Option[ConfigSSLEngineProvider])
 
   def getCipherConfig(cipher: String, enabled: String*): CipherConfig = {
-    val (localPort, remotePort) = SocketUtil.temporaryServerAddresses(2, "127.0.0.1").map(_.getPort) match {
+    val ports = SocketUtil.temporaryServerAddresses(2, "127.0.0.1").map(_.getPort)
-      case Seq(local, remote) => (local, remote)
+    assert(ports.size == 2)
-      case _                  => throw new RuntimeException()
+    val (localPort, remotePort) = (ports(0), ports(1))
-    }
     try {
       //if (true) throw new IllegalArgumentException("Ticket1978*Spec isn't enabled")
 

project/Dependencies.scala

@@ -30,7 +30,7 @@ object Dependencies {
   val scala212Version = "2.12.14"
   val scala213Version = "2.13.6"
   // To get the fix for https://github.com/lampepfl/dotty/issues/13106
-  val scala3Version = "3.0.3-RC1-bin-20210802-814fca6-NIGHTLY"
+  val scala3Version = "3.1.1-RC1-bin-20210915-ea871c2-NIGHTLY"
 
   val reactiveStreamsVersion = "1.0.3"