Update to scala 3

.gitignore

@@ -1,6 +1,10 @@
 logs
 target
+metals.sbt
+.metals/
+.vscode/
 .bsp/
+.bloop/
 /.idea
 /.idea_modules
 /.classpath

build.sbt

@@ -1,7 +1,9 @@
 import Dependencies.AkkaVersion
 import Dependencies.Scala212
 import Dependencies.Scala213
-import play.core.PlayVersion.{ current => playVersion }
+import Dependencies.Scala3
+import Dependencies.PlayVersion
+import Dependencies.PlayVersion212
 
 lazy val runChromeWebDriver = taskKey[Unit]("Run the chromewebdriver tests")
 
@@ -12,6 +14,38 @@ val akkaCluster = Seq(
   "com.typesafe.akka" %% "akka-cluster-tools" % AkkaVersion
 )
 
+val play212Dependencies = Seq(
+  "com.typesafe.play" %% "play" % PlayVersion212,
+  // Test dependencies for running a Play server
+  "com.typesafe.play" %% "play-akka-http-server" % PlayVersion212 % Test,
+  "com.typesafe.play" %% "play-logback"          % PlayVersion212 % Test,
+  // Test dependencies for Scala/Java dependency injection
+  "com.typesafe.play" %% "play-guice" % PlayVersion212 % Test,
+)
+
+val playDependencies = Seq(
+  // Production dependencies
+  "com.typesafe.play" %% "play" % PlayVersion,
+  // Test dependencies for running a Play server
+  "com.typesafe.play" %% "play-akka-http-server" % PlayVersion % Test,
+  "com.typesafe.play" %% "play-logback"          % PlayVersion % Test,
+  // Test dependencies for Scala/Java dependency injection
+  "com.typesafe.play" %% "play-guice" % PlayVersion % Test,
+)
+
+val commonDependencies = Seq(
+  // Production dependencies
+  "com.typesafe.akka" %% "akka-remote" % AkkaVersion,
+  // Test dependencies for Scala/Java dependency injection
+  macwire % Test,
+  // Test dependencies for running chrome driver
+  "io.github.bonigarcia"    % "webdrivermanager"       % "5.3.2" % Test,
+  "org.seleniumhq.selenium" % "selenium-chrome-driver" % "4.9.1" % Test,
+  // Test framework dependencies
+  "org.scalatest" %% "scalatest"       % "3.2.16" % Test,
+  "com.novocode"   % "junit-interface" % "0.11"   % Test
+)
+
 // Customise sbt-dynver's behaviour to make it work with tags which aren't v-prefixed
 (ThisBuild / dynverVTagPrefix) := false
 
@@ -21,27 +55,21 @@ lazy val root = (project in file("."))
     name := "play-socket-io",
     mimaPreviousArtifacts := Set.empty, // TODO: enable after first release
     scalaVersion := Scala213,
-    crossScalaVersions := Seq(Scala213, Scala212),
-    scalacOptions ++= Seq("-feature", "-release", "11"),
+    crossScalaVersions := Seq(Scala213, Scala212, Scala3),
+    scalacOptions ++= {
+      CrossVersion.partialVersion(scalaVersion.value) match {
+        case Some((3, n)) => Seq("-feature", "-release", "11")
+        case _            => Seq("-feature", "-release", "11", "-Xsource:3")
+      }
+    },
     (Compile / doc / scalacOptions) := Nil,
     javacOptions ++= Seq("-Xlint"),
-    libraryDependencies ++= Seq(
-      // Production dependencies
-      "com.typesafe.play" %% "play"        % playVersion,
-      "com.typesafe.akka" %% "akka-remote" % AkkaVersion,
-      // Test dependencies for running a Play server
-      "com.typesafe.play" %% "play-akka-http-server" % playVersion % Test,
-      "com.typesafe.play" %% "play-logback"          % playVersion % Test,
-      // Test dependencies for Scala/Java dependency injection
-      "com.typesafe.play" %% "play-guice" % playVersion % Test,
-      macwire              % Test,
-      // Test dependencies for running chrome driver
-      "io.github.bonigarcia"    % "webdrivermanager"       % "5.3.2" % Test,
-      "org.seleniumhq.selenium" % "selenium-chrome-driver" % "4.9.1" % Test,
-      // Test framework dependencies
-      "org.scalatest" %% "scalatest"       % "3.1.2" % Test,
-      "com.novocode"   % "junit-interface" % "0.11"  % Test
-    ),
+    libraryDependencies ++= {
+      CrossVersion.partialVersion(scalaVersion.value) match {
+        case Some((2, 12)) => commonDependencies ++ play212Dependencies
+        case _             => commonDependencies ++ playDependencies
+      }
+    },
     (Compile / PB.targets) := Seq(
       scalapb.gen() -> (Compile / sourceManaged).value
     ),
@@ -76,6 +104,7 @@ lazy val scalaChat = (project in file("samples/scala/chat"))
     name := "play-socket.io-scala-chat-example",
     organization := "com.typesafe.play",
     scalaVersion := Scala213,
+    crossScalaVersions := Seq(Scala213, Scala212, Scala3),
     libraryDependencies += macwire % Provided
   )
 
@@ -86,6 +115,7 @@ lazy val scalaMultiRoomChat = (project in file("samples/scala/multi-room-chat"))
     name := "play-socket.io-scala-multi-room-chat-example",
     organization := "com.typesafe.play",
     scalaVersion := Scala213,
+    crossScalaVersions := Seq(Scala213, Scala212, Scala3),
     libraryDependencies += macwire % Provided
   )
 
@@ -96,6 +126,7 @@ lazy val scalaClusteredChat = (project in file("samples/scala/clustered-chat"))
     name := "play-socket.io-scala-clustered-chat-example",
     organization := "com.typesafe.play",
     scalaVersion := Scala213,
+    crossScalaVersions := Seq(Scala213, Scala212, Scala3),
     libraryDependencies ++= Seq(macwire % Provided) ++ akkaCluster
   )
 
@@ -106,6 +137,7 @@ lazy val javaChat = (project in file("samples/java/chat"))
     name := "play-socket.io-java-chat-example",
     organization := "com.typesafe.play",
     scalaVersion := Scala213,
+    crossScalaVersions := Seq(Scala213, Scala212, Scala3),
     libraryDependencies += guice
   )
 
@@ -116,6 +148,7 @@ lazy val javaMultiRoomChat = (project in file("samples/java/multi-room-chat"))
     name := "play-socket.io-java-multi-room-chat-example",
     organization := "com.typesafe.play",
     scalaVersion := Scala213,
+    crossScalaVersions := Seq(Scala213, Scala212, Scala3),
     libraryDependencies ++= Seq(guice, lombok)
   )
 
@@ -126,6 +159,7 @@ lazy val javaClusteredChat = (project in file("samples/java/clustered-chat"))
     name := "play-socket.io-java-clustered-chat-example",
     organization := "com.typesafe.play",
     scalaVersion := Scala213,
+    crossScalaVersions := Seq(Scala213, Scala212, Scala3),
     libraryDependencies ++= Seq(guice, lombok) ++ akkaCluster
   )
 

project/Dependencies.scala

@@ -1,7 +1,9 @@
 object Dependencies {
   // Sync with GA (.github/workflows/build-test.yml)
-  val Scala212 = "2.12.17" // sync! see comment above
-  val Scala213 = "2.13.10" // sync! see comment above
-
-  val AkkaVersion = "2.5.32"
+  val Scala212       = "2.12.18" // sync! see comment above
+  val Scala213       = "2.13.11" // sync! see comment above
+  val Scala3         = "3.3.0-RC6"
+  val AkkaVersion    = "2.6.20"
+  val PlayVersion    = "2.9.0-M4"
+  val PlayVersion212 = "2.8.9"
 }

src/main/scala/play/engineio/EngineIO.scala

@@ -26,9 +26,11 @@ import play.api.inject.Module
 import play.api.mvc._
 import play.engineio.EngineIOManagerActor._
 import play.engineio.protocol._
+import play.engineio.protocol.EngineIOTransport
 
 import scala.concurrent.ExecutionContext
 import scala.concurrent.Future
+import scala.concurrent.duration.FiniteDuration
 import scala.concurrent.duration._
 import scala.util.Failure
 import scala.util.Success
@@ -86,8 +88,8 @@ final class EngineIOController(
 )(implicit ec: ExecutionContext)
     extends AbstractController(controllerComponents) {
 
-  private val log              = Logger(classOf[EngineIOController])
-  private implicit val timeout = Timeout(config.pingTimeout)
+  private val log                       = Logger(classOf[EngineIOController])
+  private implicit val timeout: Timeout = Timeout(config.pingTimeout)
 
   /**
    * The endpoint to route to from a router.

src/main/scala/play/engineio/EngineIOManagerActor.scala

@@ -94,7 +94,7 @@ class EngineIOManagerActor(config: EngineIOConfig, sessionProps: Props) extends
         case Some(sessionActor) =>
           sessionActor.tell(close, sender())
         case None =>
-          sender ! Done
+          sender() ! Done
       }
 
     case message: SessionMessage =>

src/main/scala/play/engineio/EngineIOSessionActor.scala

@@ -9,6 +9,7 @@ import akka.actor.ActorRef
 import akka.actor.DeadLetterSuppression
 import akka.actor.Props
 import akka.actor.Status
+import akka.util.Timeout
 import akka.pattern.pipe
 import akka.stream._
 import akka.stream.scaladsl._
@@ -154,11 +155,11 @@ class EngineIOSessionActor[SessionData](
     case Close(_, transport, requestId) =>
       debug(requestId, transport, "Requested to close session")
       context.stop(self)
-      sender ! Done
+      sender() ! Done
 
     case message: SessionMessage =>
       debug(message.requestId, message.transport, s"Unknown session id")
-      sender ! Status.Failure(UnknownSessionId(sid))
+      sender() ! Status.Failure(UnknownSessionId(sid))
       context.stop(self)
   }
 
@@ -170,9 +171,9 @@ class EngineIOSessionActor[SessionData](
         .recover { case e =>
           ConnectionRefused(e)
         }
-        .pipeTo(self)(sender)
+        .pipeTo(self)(sender())
     } catch {
-      case NonFatal(e) => self.tell(ConnectionRefused(e), sender)
+      case NonFatal(e) => self.tell(ConnectionRefused(e), sender())
     }
     context.become(connecting)
   }
@@ -183,7 +184,7 @@ class EngineIOSessionActor[SessionData](
 
     case Connected(flow, requestId) =>
       log.debug("{} - Connection successful", sid)
-      sender ! Packets(
+      sender() ! Packets(
         sid,
         activeTransport,
         Seq(
@@ -203,11 +204,11 @@ class EngineIOSessionActor[SessionData](
       doConnect(flow)
 
     case ConnectionRefused(e) =>
-      sender ! Status.Failure(e)
+      sender() ! Status.Failure(e)
 
     case Close(_, transport, requestId) =>
       debug(requestId, transport, "Requested to close session")
-      sender ! Done
+      sender() ! Done
       context.stop(self)
   }
 
@@ -237,8 +238,8 @@ class EngineIOSessionActor[SessionData](
       .expand(_.iterator)
       .via(flow)
       .batch(4, messagesToPackets)(_ ++ messagesToPackets(_))
-      .toMat(Sink.queue[Seq[EngineIOPacket]])(Keep.both)
-      .run
+      .toMat(Sink.queue[Seq[EngineIOPacket]]())(Keep.both)
+      .run()
 
     sourceQueue = sourceQ
     sinkQueue = sinkQ
@@ -264,26 +265,26 @@ class EngineIOSessionActor[SessionData](
             existingRequestId
           )
           existing ! Close(sid, transport, requestId)
-          storeRequester(sender, requestId, transport)
+          storeRequester(sender(), requestId, transport)
 
         case None if transport != activeTransport =>
           packetsToSendByNonActiveTransport.get(transport) match {
             case Some(packets) =>
               debug(requestId, transport, "Sending message to non active transport")
-              sender ! Packets(sid, transport, packets, requestId)
+              sender() ! Packets(sid, transport, packets, requestId)
             case None =>
               debug(requestId, transport, "Retrieve from non active transport, waiting")
-              storeRequester(sender, requestId, transport)
+              storeRequester(sender(), requestId, transport)
           }
 
         case None if packetsToSend.isEmpty =>
           debug(requestId, transport, "Retrieve while no packets, waiting")
-          storeRequester(sender, requestId, transport)
+          storeRequester(sender(), requestId, transport)
 
         case None =>
           // We have packets to send
           debug(requestId, transport, "Retrieve with {} packets to send", packetsToSend.length)
-          sender ! Packets(sid, transport, packetsToSend, requestId)
+          sender() ! Packets(sid, transport, packetsToSend, requestId)
           packetsToSend = Nil
           requestMorePackets()
       }
@@ -378,14 +379,14 @@ class EngineIOSessionActor[SessionData](
     if (messagesToPush.nonEmpty) {
       if (currentlyPushingMessages) {
         messagesReceived ++= messagesToPush
-        messagesReceivedSenders += sender
+        messagesReceivedSenders += sender()
       } else {
         sourceQueue.offer(messagesToPush).map(_ => MessagesPushed).pipeTo(self)
         currentlyPushingMessages = true
-        sender ! Done
+        sender() ! Done
       }
     } else {
-      sender ! Done
+      sender() ! Done
     }
   }
 
@@ -456,7 +457,7 @@ class EngineIOSessionActor[SessionData](
       debug(requestId, transport, "Telling poller to go away to work around engine.io upgrade race condition")
       requester ! Packets(sid, Polling, Seq(Utf8EngineIOPacket(EngineIOPacketType.Noop, "")), requestId)
     } else {
-      retrieveRequesters += (transport -> RetrieveRequester(sender, requestId))
+      retrieveRequesters += (transport -> RetrieveRequester(sender(), requestId))
     }
   }
 

src/main/scala/play/socketio/SocketIOSessionFlow.scala

@@ -344,7 +344,7 @@ private class SocketIOSessionStage[SessionData](
                     namespace,
                     connectToNamespaceCallback.applyOrElse(
                       (session, ns),
-                      { _: (SocketIOSession[SessionData], String) => throw NamespaceNotFound(namespace) }
+                      { (_: (SocketIOSession[SessionData], String)) => throw NamespaceNotFound(namespace) }
                     )
                   )
               }

src/main/scala/play/socketio/protocol/SocketIOProtocol.scala

@@ -163,7 +163,7 @@ object SocketIOPacket {
     }
 
     TextEngineIOMessage(message.toString) ::
-      extraPackets.map(BinaryEngineIOMessage)
+      extraPackets.map(play.engineio.BinaryEngineIOMessage.apply)
   }
 
   /**

src/main/scala/play/socketio/scaladsl/SocketIOEventCodec.scala

@@ -65,7 +65,7 @@ object SocketIOEventCodec {
       override def applyOrElse[A1 <: SocketIOEvent, B1 >: T](event: A1, default: (A1) => B1) = {
         decoders
           .andThen(decoder => decoder.apply(event))
-          .applyOrElse(event.name, { _: String => default(event) })
+          .applyOrElse(event.name, { (_: String) => default(event) })
       }
     }
 

src/test/scala/play/socketio/scaladsl/SocketIOEventCodecSpec.scala

@@ -184,7 +184,7 @@ class SocketIOEventCodecSpec extends AnyWordSpec with Matchers with OptionValues
       val encoder = encodeByType[Any] {
         case _: String => "string" -> encodeJson[String]
         case _: Int =>
-          "int" -> encodeJson[String].compose { i: Int => i.toString }
+          "int" -> encodeJson[String].compose { (i: Int) => i.toString }
       }
 
       val e1 = encoder("arg")

src/test/scala/play/socketio/scaladsl/TestSocketIOScalaApplication.scala

@@ -77,7 +77,7 @@ class TestSocketIOScalaApplication(initialSettings: Map[String, AnyRef]) extends
 
     val (testDisconnectQueue, testDisconnectFlow) = {
       val (sourceQueue, source) =
-        Source.queue[SocketIOEvent](10, OverflowStrategy.backpressure).toMat(BroadcastHub.sink)(Keep.both).run
+        Source.queue[SocketIOEvent](10, OverflowStrategy.backpressure).toMat(BroadcastHub.sink)(Keep.both).run()
       (sourceQueue, Flow.fromSinkAndSource(Sink.ignore, source))
     }