[BE2] migrate to Scala 3

.github/workflows/ci.yaml

@@ -259,9 +259,6 @@ jobs:
       - name: Report coverage
         run: sbt coverageReport
 
-      - name: Run static analysis (ScapeGoat)
-        run: sbt scapegoat
-
       - name: Run Sonar scanner
         env:
           SONAR_HOST_URL: https://sonarcloud.io

be2-scala/build.sbt

@@ -3,44 +3,21 @@ import sbtsonar.SonarPlugin.autoImport.sonarProperties
 
 name := "pop"
 
-scalaVersion := "2.13.7"
+scalaVersion := "3.2.0"
 
 // Recommended 2.13 Scala flags (https://nathankleyn.com/2019/05/13/recommended-scalac-flags-for-2-13) slightly adapted for PoP
 scalacOptions ++= Seq(
     "-deprecation", // Emit warning and location for usages of deprecated APIs.
-    "-explaintypes", // Explain type errors in more detail.
+    "-explain-types", // Explain type errors in more detail.
     "-feature", // Emit warning and location for usages of features that should be imported explicitly.
     "-language:existentials", // Existential types (besides wildcard types) can be written and inferred
     "-language:experimental.macros", // Allow macro definition (besides implementation and application)
     "-language:higherKinds", // Allow higher-kinded types
     "-language:implicitConversions", // Allow definition of implicit functions called views
     "-unchecked", // Enable additional warnings where generated code depends on assumptions.
-    "-Xcheckinit", // Wrap field accessors to throw an exception on uninitialized access.
     "-Xfatal-warnings", // Fail the compilation if there are any warnings.
-    "-Xlint:adapted-args", // Warn if an argument list is modified to match the receiver.
-    "-Xlint:constant", // Evaluation of a constant arithmetic expression results in an error.
-    "-Xlint:delayedinit-select", // Selecting member of DelayedInit.
-    "-Xlint:doc-detached", // A Scaladoc comment appears to be detached from its element.
-    "-Xlint:inaccessible", // Warn about inaccessible types in method signatures.
-    "-Xlint:infer-any", // Warn when a type argument is inferred to be `Any`.
-    "-Xlint:missing-interpolator", // A string literal appears to be missing an interpolator id.
-    "-Xlint:nullary-unit", // Warn when nullary methods return Unit.
-    "-Xlint:option-implicit", // Option.apply used implicit view.
-    "-Xlint:package-object-classes", // Class or object defined in package object.
-    "-Xlint:poly-implicit-overload", // Parameterized overloaded implicit methods are not visible as view bounds.
-    "-Xlint:private-shadow", // A private field (or class parameter) shadows a superclass field.
-    "-Xlint:stars-align", // Pattern sequence wildcard must align with sequence component.
-    "-Xlint:type-parameter-shadow", // A local type parameter shadows a type already in scope.
-    "-Ywarn-extra-implicit", // Warn when more than one implicit parameter section is defined.
-    "-Ywarn-numeric-widen", // Warn when numerics are widened.
-    "-Ycache-plugin-class-loader:last-modified", // Enables caching of classloaders for compiler plugins
-    "-Ycache-macro-class-loader:last-modified", // and macro definitions. This can lead to performance improvements.
 )
 
-Scapegoat/ scalacOptions -= "-Xfatal-warnings"
-// Temporarily report scapegoat errors as warnings, to avoid broken builds
-Scapegoat/ scalacOptions += "-P:scapegoat:overrideLevels:all=Warning"
-
 // Reload changes automatically
 Global / onChangedBuildSource := ReloadOnSourceChanges
 Global / cancelable := true
@@ -89,15 +66,9 @@ copyProtocolTask := {
 Compile/ run/ mainClass := Some("ch.epfl.pop.Server")
 Compile/ packageBin/ mainClass := Some("ch.epfl.pop.Server")
 
-lazy val scoverageSettings = Seq(
-  Compile/ coverageEnabled := true,
-  Test/ coverageEnabled := true,
-  packageBin/ coverageEnabled := false,
-)
-
-ThisBuild/ scapegoatVersion := "1.4.11"
-
-scapegoatReports := Seq("xml", "html")
+// https://github.com/ckipp01/dotty/blob/2fc33a36ea19752920d17596b5a6194c815a1873/docs/_docs/usage/coverage.md
+Compile/ compile/ scalacOptions +=
+  s"-coverage-out:target/scala-${scalaVersion.value}/scoverage-data"
 
 // Configure Sonar
 sonarProperties := Map(
@@ -108,10 +79,9 @@ sonarProperties := Map(
   "sonar.tests" -> "src/test/scala",
 
   "sonar.sourceEncoding" -> "UTF-8",
-  "sonar.scala.version" -> "2.13.7",
+  "sonar.scala.version" -> scalaVersion.value,
   // Paths to the test and coverage reports
-  "sonar.scala.coverage.reportPaths" -> "./target/scala-2.13/scoverage-report/scoverage.xml",
-  "sonar.scala.scapegoat.reportPaths" -> "./target/scala-2.13/scapegoat-report/scapegoat.xml"
+  "sonar.scala.coverage.reportPaths" -> "./target/scala-3/scoverage-report/scoverage.xml",
 )
 
 assembly/ assemblyMergeStrategy := {
@@ -131,7 +101,7 @@ val AkkaHttpVersion = "10.2.9"
 
 libraryDependencies ++= Seq(
     "com.typesafe.akka" %% "akka-stream-typed" % AkkaVersion,   // Akka streams (Graph)
-    "com.typesafe.akka" %% "akka-http" % AkkaHttpVersion,       // Akka http (WebSockets)
+    ("com.typesafe.akka" %% "akka-http" % AkkaHttpVersion).cross(CrossVersion.for3Use2_13),       // Akka http (WebSockets)
     "com.typesafe.akka" %% "akka-cluster-tools" % AkkaVersion,  // Akka distributed publish/subscribe cluster
 
     "ch.qos.logback" % "logback-classic" % "1.1.3" % Runtime,   // Akka logging library

be2-scala/project/plugins.sbt

@@ -1,7 +1,5 @@
-addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.6.1")
-addSbtPlugin("com.sksamuel.scapegoat" % "sbt-scapegoat" % "1.1.1")
+addSbtPlugin("org.scoverage" % "sbt-scoverage" % "2.0.0-M4")
 addSbtPlugin("com.sonar-scala" % "sbt-sonar" % "2.3.0")
 addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "1.1.0")
 addSbtPlugin("com.rallyhealth.sbt" % "sbt-git-versioning" % "1.6.0")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.4.6")
-addSbtPlugin("ch.epfl.scala" % "sbt-scala3-migrate" % "0.5.1")

be2-scala/src/main/scala/ch/epfl/pop/Server.scala

@@ -55,7 +55,7 @@ object Server {
       val bindingFuture = Http().newServerAt(config.interface, config.port).bindFlow(publishSubscribeRoute)
 
       bindingFuture.onComplete {
-        case Success(_) => println(f"ch.epfl.pop.Server online at ws://${config.interface}:${config.port}/${config.path}")
+        case Success(_) => println(s"ch.epfl.pop.Server online at ws://${config.interface}:${config.port}/${config.path}")
         case Failure(_) =>
           logger.error(
             "ch.epfl.pop.Server failed to start. Terminating actor system"

be2-scala/src/main/scala/ch/epfl/pop/model/objects/ElectionChannel.scala

@@ -23,7 +23,7 @@ object ElectionChannel {
       */
     def extractMessages[T: reflect.ClassTag](dbActor: AskableActorRef = DbActor.getInstance): Future[List[(Message, T)]] = {
       for {
-        DbActor.DbActorCatchupAck(messages) <- dbActor ? DbActor.Catchup(channel)
+        case DbActor.DbActorCatchupAck(messages) <- dbActor ? DbActor.Catchup(channel)
         result <- Future.traverse(messages.flatMap(message =>
           message.decodedData match {
             case Some(t: T) => Some((message, t))

be2-scala/src/main/scala/ch/epfl/pop/model/objects/Transaction.scala

@@ -41,8 +41,8 @@ final case class Transaction(
   }
 
   private def signaturePayload =
-    Base64Data.encode(inputs.map { txin => f"${txin.txOutHash}${txin.txOutIndex}" }.reduce(_ + _) +
-      outputs.map { txout => f"${txout.value}${txout.script.`type`}${txout.script.pubkeyHash.base64Data}" }.reduce(_ + _))
+    Base64Data.encode(inputs.map { txin => s"${txin.txOutHash}${txin.txOutIndex}" }.reduce(_ + _) +
+      outputs.map { txout => s"${txout.value}${txout.script.`type`}${txout.script.pubkeyHash.base64Data}" }.reduce(_ + _))
 
   /** This ensures the validity of the signatures, not that the funds are unspent.
     */

be2-scala/src/main/scala/ch/epfl/pop/model/objects/Uint53.scala

@@ -26,7 +26,9 @@ object Uint53 {
     */
   def safeSum(seq: IterableOnce[Uint53]): Either[ArithmeticOverflowError, Uint53] = {
     var acc = 0L
-    for (v <- seq.iterator) {
+    val it = seq.iterator
+    while (it.hasNext) {
+      val v = it.next
       require(inRange(v), s"value $v out of range for uint53")
       acc += v
       if (acc > MaxValue)

be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/ElectionHandler.scala

@@ -128,7 +128,7 @@ class ElectionHandler(dbRef: => AskableActorRef) extends MessageHandler {
       castsVotesElections <- electionChannel.getLastVotes(dbActor)
       setupMessage <- electionChannel.getSetupMessage(dbActor)
       questionToBallots = setupMessage.questions.map(question => question.id -> question.ballot_options).toMap
-      DbActorReadElectionDataAck(electionData) <- dbActor ? DbActor.ReadElectionData(setupMessage.id)
+      case DbActorReadElectionDataAck(electionData) <- dbActor ? DbActor.ReadElectionData(setupMessage.id)
     } yield {
       val resultsTable = mutable.HashMap.from(for {
         (question, ballots) <- questionToBallots

be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/LaoHandler.scala

@@ -30,7 +30,7 @@ case object LaoHandler extends MessageHandler {
         val reactionChannel: Channel = Channel(s"$laoChannel${Channel.REACTIONS_CHANNEL_PREFIX}")
         // we get access to the canonical address of the server
         val config = ServerConf(appConf)
-        val address: Option[String] = Some(f"ws://${config.interface}:${config.port}/${config.path}")
+        val address: Option[String] = Some(s"ws://${config.interface}:${config.port}/${config.path}")
 
         val combined = for {
           // check whether the lao already exists in db

be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/MessageHandler.scala

@@ -27,16 +27,17 @@ trait MessageHandler extends AskPatternConstants {
     *   the database answer wrapped in a [[scala.concurrent.Future]]
     */
   def dbAskWrite(rpcRequest: JsonRpcRequest): Future[GraphMessage] = {
-    val m: Message = rpcRequest.getParamsMessage.getOrElse(
-      return Future {
-        Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbAskWrite failed : retrieve empty rpcRequest message", rpcRequest.id))
-      }
-    )
-
-    val askWrite = dbActor ? DbActor.Write(rpcRequest.getParamsChannel, m)
-    askWrite.transformWith {
-      case Success(_) => Future(Left(rpcRequest))
-      case _          => Future(Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbAskWrite failed : could not write message $m", rpcRequest.id)))
+    rpcRequest.getParamsMessage match {
+      case None =>
+        Future {
+          Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbAskWrite failed : retrieve empty rpcRequest message", rpcRequest.id))
+        }
+      case Some(m) =>
+        val askWrite = dbActor ? DbActor.Write(rpcRequest.getParamsChannel, m)
+        askWrite.transformWith {
+          case Success(_) => Future(Left(rpcRequest))
+          case _          => Future(Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbAskWrite failed : could not write message $m", rpcRequest.id)))
+        }
     }
   }
 
@@ -48,16 +49,17 @@ trait MessageHandler extends AskPatternConstants {
     *   the database answer wrapped in a [[scala.concurrent.Future]]
     */
   def dbAskWritePropagate(rpcRequest: JsonRpcRequest): Future[GraphMessage] = {
-    val m: Message = rpcRequest.getParamsMessage.getOrElse(
-      return Future {
-        Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbAskWritePropagate failed : retrieve empty rpcRequest message", rpcRequest.id))
-      }
-    )
-
-    val askWritePropagate = dbActor ? DbActor.WriteAndPropagate(rpcRequest.getParamsChannel, m)
-    askWritePropagate.transformWith {
-      case Success(_) => Future(Left(rpcRequest))
-      case _          => Future(Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbAskWritePropagate failed : could not write & propagate message $m", rpcRequest.id)))
+    rpcRequest.getParamsMessage match {
+      case None =>
+        Future {
+          Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbAskWritePropagate failed : retrieve empty rpcRequest message", rpcRequest.id))
+        }
+      case Some(m) =>
+        val askWritePropagate = dbActor ? DbActor.WriteAndPropagate(rpcRequest.getParamsChannel, m)
+        askWritePropagate.transformWith {
+          case Success(_) => Future(Left(rpcRequest))
+          case _          => Future(Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbAskWritePropagate failed : could not write & propagate message $m", rpcRequest.id)))
+        }
     }
   }
 
@@ -75,23 +77,24 @@ trait MessageHandler extends AskPatternConstants {
     *   the database answer wrapped in a [[scala.concurrent.Future]]
     */
   def dbBroadcast(rpcMessage: JsonRpcRequest, channel: Channel, broadcastData: Base64Data, broadcastChannel: Channel): Future[GraphMessage] = {
-    val m: Message = rpcMessage.getParamsMessage.getOrElse(
-      return Future {
-        Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbAskWritePropagate failed : retrieve empty rpcRequest message", rpcMessage.id))
-      }
-    )
-
-    val combined = for {
-      DbActorReadLaoDataAck(laoData) <- dbActor ? DbActor.ReadLaoData(channel)
-      broadcastSignature: Signature = laoData.privateKey.signData(broadcastData)
-      broadcastId: Hash = Hash.fromStrings(broadcastData.toString, broadcastSignature.toString)
-      broadcastMessage: Message = Message(broadcastData, laoData.publicKey, broadcastSignature, broadcastId, List.empty)
-      _ <- dbActor ? DbActor.WriteAndPropagate(broadcastChannel, broadcastMessage)
-    } yield ()
+    rpcMessage.getParamsMessage match {
+      case None =>
+        Future {
+          Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbAskWritePropagate failed : retrieve empty rpcRequest message", rpcMessage.id))
+        }
+      case Some(m) =>
+        val combined = for {
+          case DbActorReadLaoDataAck(laoData) <- dbActor ? DbActor.ReadLaoData(channel)
+          broadcastSignature: Signature = laoData.privateKey.signData(broadcastData)
+          broadcastId: Hash = Hash.fromStrings(broadcastData.toString, broadcastSignature.toString)
+          broadcastMessage: Message = Message(broadcastData, laoData.publicKey, broadcastSignature, broadcastId, List.empty)
+          _ <- dbActor ? DbActor.WriteAndPropagate(broadcastChannel, broadcastMessage)
+        } yield ()
 
-    combined.transformWith {
-      case Success(_) => Future(Left(rpcMessage))
-      case _          => Future(Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbBroadcast failed : could not read and broadcast message $m", rpcMessage.id)))
+        combined.transformWith {
+          case Success(_) => Future(Left(rpcMessage))
+          case _          => Future(Right(PipelineError(ErrorCodes.SERVER_ERROR.id, s"dbBroadcast failed : could not read and broadcast message $m", rpcMessage.id)))
+        }
     }
   }
 }

be2-scala/src/main/scala/ch/epfl/pop/pubsub/graph/handlers/WitnessHandler.scala

@@ -35,7 +35,7 @@ class WitnessHandler(dbRef: => AskableActorRef) extends MessageHandler {
       case Some(_) =>
         val combined = for {
           // add new witness signature to existing ones
-          DbActorAddWitnessSignatureAck(witnessMessage) <- dbActor ? DbActor.AddWitnessSignature(channel, messageId, signature)
+          case DbActorAddWitnessSignatureAck(witnessMessage) <- dbActor ? DbActor.AddWitnessSignature(channel, messageId, signature)
           // overwrites the message containing now the witness signature in the db
           _ <- dbActor ? DbActor.WriteAndPropagate(channel, witnessMessage)
         } yield ()

be2-scala/src/test/scala/ch/epfl/pop/model/objects/PublicKeySuite.scala

@@ -17,7 +17,7 @@ class PublicKeySuite extends FunSuite with Matchers {
 
   test("pubkey hash matches example data") {
     for (suffix <- Seq("", "2")) {
-      val Seq(JsString(pubkeyData), JsString(pubkeyHash)) = data.asJsObject.getFields(s"publicKey$suffix", s"publicKeyHash$suffix")
+      val Seq(JsString(pubkeyData), JsString(pubkeyHash)) = data.asJsObject.getFields(s"publicKey$suffix", s"publicKeyHash$suffix"): @unchecked
       val pubkey = PublicKey(Base64Data(pubkeyData))
       pubkey.hash.base64Data should equal(Base64Data(pubkeyHash))
     }

be2-scala/src/test/scala/util/examples/data/TestKeyPairs.scala

@@ -18,7 +18,7 @@ object TestKeyPairs {
 
   val keypairs: Vector[KeyPairWithHash] = for (suffix <- Vector("", "2")) yield {
     val Seq(JsString(privkeyData), JsString(pubkeyData), JsString(pubkeyHash)) =
-      raw.getFields(s"privateKey$suffix", s"publicKey$suffix", s"publicKeyHash$suffix")
+      raw.getFields(s"privateKey$suffix", s"publicKey$suffix", s"publicKeyHash$suffix"): @unchecked
     val fixedPrivkeyData = Base64Data(privkeyData).decode().take(32)
     KeyPairWithHash(KeyPair(PrivateKey(Base64Data.encode(fixedPrivkeyData)), PublicKey(Base64Data(pubkeyData))), Base64Data(pubkeyHash))
   }