Scala 2.13 cross-build upgrade

build.sc

@@ -6,147 +6,183 @@ import coursier.maven.MavenRepository
 import mill.scalalib.{PublishModule, ScalaModule}
 import mill.scalalib.publish.{Developer, License, PomSettings, VersionControl}
 
-trait ScalanetModule extends ScalaModule {
-  override def scalaVersion = "2.12.10"
-
-  override def repositories =
-    super.repositories ++ Seq(
-      MavenRepository("https://oss.sonatype.org/content/repositories/releases"),
-      MavenRepository("https://oss.sonatype.org/content/repositories/snapshots")
-    )
-
-  private val commonScalacOptions = Seq(
-    "-unchecked",
-    "-language:postfixOps",
-    "-deprecation",
-    "-feature",
-    "-Xfatal-warnings",
+object csm extends Cross[ScalanetModule]("2.12.10", "2.13.4")
+
+class ScalanetModule(crossVersion: String) extends Module {
+
+  // A cross build is now a `root` of the module:
+  // > mill show csm[2.13.4].scalanet.sources
+  // [1/1] show 
+  // [1/1] show > [1/1] csm[2.13.4].scalanet.sources 
+  // [
+  //     "ref:c984eca8: ../csm/2.13.4/scalanet/src"
+  // ]
+  // As soon as there is no such folder as /csm/2.13.4/
+  // We have to navigate up two times on the module tree.
+  //
+  // > mill show csm[2.13.4].scalanet.sources
+  //            // some output omitted //
+  //     "ref:c984eca8: ../scalanet/src"
+  override def millSourcePath = super.millSourcePath / os.up / os.up
+
+
+  // scala 2.12 - only options
+  // it causes errors when built against 2.13 (and vice-versa):
+  // [error] bad option: '-Ywarn-unused-import'
+  private val `scala 2.12 options`: Seq[String] = Seq(
     "-Xlint:unsound-match",
     "-Ywarn-inaccessible",
     "-Ywarn-unused-import",
     "-Ypartial-unification",
-    "-J-Xmx1.5G",
-    "-J-Xms1.5G",
-    "-J-XX:MaxMetaspaceSize=512m",
-    "-encoding",
-    "utf-8"
+    "-Ywarn-value-discard"
   )
 
-  override def scalacOptions =
-    commonScalacOptions ++ Seq("-Ywarn-value-discard")
 
-  // `extends Tests` uses the context of the module in which it's defined,
-  // which is why the trait is defined here not within `scalanet`, otherwise
-  // it wouldn't work for `kademlia` for example.
-  trait TestModule extends Tests {
-    override def scalacOptions =
-      commonScalacOptions
+  // scala 2.13 might have another set of options
+  private val `scala 2.13 options`: Seq[String] = Nil
+
+  trait ScalanetModule extends ScalaModule { 
+    override def scalaVersion = crossVersion
+
+    override def repositories =
+      super.repositories ++ Seq(
+        MavenRepository("https://oss.sonatype.org/content/repositories/releases"),
+        MavenRepository("https://oss.sonatype.org/content/repositories/snapshots")
+      )
+
+    private val commonScalacOptions = Seq(
+      "-unchecked",
+      "-language:postfixOps",
+      "-deprecation",
+      "-feature",
+      "-Xfatal-warnings",
+      "-J-Xmx1.5G",
+      "-J-Xms1.5G",
+      "-J-XX:MaxMetaspaceSize=512m",
+      "-encoding",
+      "utf-8"
+    )
+
+    private val versionOptions = crossVersion.take(4) match { 
+      case "2.12" => `scala 2.12 options`
+      case "2.13" => `scala 2.13 options`
+    }
 
-    override def testFrameworks =
-      Seq("org.scalatest.tools.Framework")
+    override def scalacOptions = commonScalacOptions ++ versionOptions
 
-    override def ivyDeps = Agg(
-      ivy"org.scalatest::scalatest:3.0.5",
-      ivy"org.scalacheck::scalacheck:1.14.0",
-      ivy"ch.qos.logback:logback-core:1.2.3",
-      ivy"ch.qos.logback:logback-classic:1.2.3",
-      ivy"org.mockito:mockito-core:2.21.0"
-    )
+    // `extends Tests` uses the context of the module in which it's defined,
+    // which is why the trait is defined here not within `scalanet`, otherwise
+    // it wouldn't work for `kademlia` for example.
+    trait TestModule extends Tests {
+      override def scalacOptions = ScalanetModule.this.scalacOptions
 
-    override def moduleDeps: Seq[JavaModule] =
-      Seq(scalanet)
+      override def testFrameworks =
+        Seq("org.scalatest.tools.Framework")
 
-    def single(args: String*) = T.command {
-      super.runMain("org.scalatest.run", args: _*)
+      override def ivyDeps = Agg(
+        ivy"org.scalatest::scalatest:3.0.9",
+        ivy"org.scalacheck::scalacheck:1.14.0",
+        ivy"ch.qos.logback:logback-core:1.2.3",
+        ivy"ch.qos.logback:logback-classic:1.2.3",
+        ivy"org.mockito:mockito-core:2.21.0"
+      )
+
+      override def moduleDeps: Seq[JavaModule] =
+        Seq(scalanet)
+
+      def single(args: String*) = T.command {
+        super.runMain("org.scalatest.run", args: _*)
+      }
     }
   }
-}
 
-// In objects inheriting this trait, use `override def moduleDeps: Seq[PublishModule]`
-// to point at other modules that also get published. In other cases such as tests
-// it can be `override def moduleDeps: Seq[JavaModule]`.
-trait ScalanetPublishModule extends PublishModule {
-  def description: String
-
-  override def publishVersion = "0.5.0-SNAPSHOT"
-
-  override def pomSettings = PomSettings(
-    description = description,
-    organization = "io.iohk",
-    url = "https://github.com/input-output-hk/scalanet",
-    licenses = Seq(License.`Apache-2.0`),
-    versionControl = VersionControl.github("input-output-hk", "scalanet"),
-    developers = Seq()
-  )
-}
 
-// ScoverageModule creates bug when using custom repositories:
-// https://github.com/lihaoyi/mill/issues/620
-//object scalanet extends ScalaModule with PublishModule with ScoverageModule {
-object scalanet extends ScalanetModule with ScalanetPublishModule {
-
-  override val description =
-    "Asynchronous, strongly typed, resource-managed networking library, written in Scala with support for a variety of network technologies"
-
-  override def ivyDeps = Agg(
-    ivy"io.monix::monix:3.2.2",
-    ivy"com.github.nscala-time::nscala-time:2.22.0",
-    ivy"com.chuusai::shapeless:2.3.3",
-    ivy"com.typesafe.scala-logging::scala-logging:3.9.2",
-    ivy"com.github.jgonian:commons-ip-math:1.32",
-    ivy"org.slf4j:slf4j-api:1.7.25",
-    ivy"io.netty:netty-all:4.1.51.Final",
-    ivy"org.eclipse.californium:scandium:2.0.0-M15",
-    ivy"org.eclipse.californium:element-connector:2.0.0-M15",
-    ivy"org.scodec::scodec-bits:1.1.12",
-    ivy"org.scodec::scodec-core:1.11.7",
-    ivy"org.bouncycastle:bcprov-jdk15on:1.64",
-    ivy"org.bouncycastle:bcpkix-jdk15on:1.64",
-    ivy"org.bouncycastle:bctls-jdk15on:1.64"
-  )
+  // In objects inheriting this trait, use `override def moduleDeps: Seq[PublishModule]`
+  // to point at other modules that also get published. In other cases such as tests
+  // it can be `override def moduleDeps: Seq[JavaModule]`.
+  trait ScalanetPublishModule extends PublishModule {
+    def description: String
 
-  def scoverageVersion = "1.3.1"
+    override def publishVersion = "0.5.1-SNAPSHOT"
 
-  // Scoverage disabled
-  // object test extends ScoverageTests {
-  object ut extends TestModule
+    override def pomSettings = PomSettings(
+      description = description,
+      organization = "io.iohk",
+      url = "https://github.com/input-output-hk/scalanet",
+      licenses = Seq(License.`Apache-2.0`),
+      versionControl = VersionControl.github("input-output-hk", "scalanet"),
+      developers = Seq()
+    )
+  }
 
-  object discovery extends ScalanetModule with ScalanetPublishModule {
+  // ScoverageModule creates bug when using custom repositories:
+  // https://github.com/lihaoyi/mill/issues/620
+  //object scalanet extends ScalaModule with PublishModule with ScoverageModule {
+  object scalanet extends ScalanetModule with ScalanetPublishModule {
 
     override val description =
-      "Implementation of peer-to-peer discovery algorithms such as that of Ethereum."
+      "Asynchronous, strongly typed, resource-managed networking library, written in Scala with support for a variety of network technologies"
 
-    override def moduleDeps: Seq[PublishModule] =
-      Seq(scalanet)
+    override def ivyDeps = Agg(
+      ivy"io.monix::monix:3.3.0",
+      ivy"com.github.nscala-time::nscala-time:2.22.0",
+      ivy"com.chuusai::shapeless:2.3.3",
+      ivy"com.typesafe.scala-logging::scala-logging:3.9.2",
+      ivy"com.github.jgonian:commons-ip-math:1.32",
+      ivy"org.slf4j:slf4j-api:1.7.25",
+      ivy"io.netty:netty-all:4.1.51.Final",
+      ivy"org.eclipse.californium:scandium:2.0.0-M15",
+      ivy"org.eclipse.californium:element-connector:2.0.0-M15",
+      ivy"org.scodec::scodec-bits:1.1.12",
+      ivy"org.scodec::scodec-core:1.11.7",
+      ivy"org.bouncycastle:bcprov-jdk15on:1.64",
+      ivy"org.bouncycastle:bcpkix-jdk15on:1.64",
+      ivy"org.bouncycastle:bctls-jdk15on:1.64"
+    )
 
-    object ut extends TestModule {
-      override def moduleDeps: Seq[JavaModule] =
-        super.moduleDeps ++ Seq(scalanet.discovery, scalanet.ut)
-    }
+    def scoverageVersion = "1.3.1"
 
-    object it extends TestModule {
-      override def moduleDeps: Seq[JavaModule] =
-        super.moduleDeps ++ Seq(scalanet.discovery.ut)
-    }
-  }
+    // Scoverage disabled
+    // object test extends ScoverageTests {
+    object ut extends TestModule
 
-  object examples extends ScalanetModule {
-    override def ivyDeps = Agg(
-      ivy"ch.qos.logback:logback-core:1.2.3",
-      ivy"ch.qos.logback:logback-classic:1.2.3",
-      ivy"org.mockito:mockito-core:2.21.0",
-      ivy"com.github.pureconfig::pureconfig:0.11.1",
-      ivy"com.github.scopt::scopt:3.7.1",
-      ivy"io.monix::monix:3.2.2",
-      ivy"org.scala-lang.modules::scala-parser-combinators:1.1.2"
-    )
+    object discovery extends ScalanetModule with ScalanetPublishModule {
+
+      override val description =
+        "Implementation of peer-to-peer discovery algorithms such as that of Ethereum."
+
+      override def moduleDeps: Seq[PublishModule] =
+        Seq(scalanet)
 
-    override def moduleDeps: Seq[JavaModule] =
-      Seq(scalanet, scalanet.discovery)
+      object ut extends TestModule {
+        override def moduleDeps: Seq[JavaModule] =
+          super.moduleDeps ++ Seq(scalanet.discovery, scalanet.ut)
+      }
+
+      object it extends TestModule {
+        override def moduleDeps: Seq[JavaModule] =
+          super.moduleDeps ++ Seq(scalanet.discovery.ut)
+      }
+    }
+
+    object examples extends ScalanetModule {
+      override def ivyDeps = Agg(
+        ivy"ch.qos.logback:logback-core:1.2.3",
+        ivy"ch.qos.logback:logback-classic:1.2.3",
+        ivy"org.mockito:mockito-core:2.21.0",
+        ivy"com.github.pureconfig::pureconfig:0.11.1",
+        ivy"com.github.scopt::scopt:3.7.1",
+        ivy"io.monix::monix:3.2.2",
+        ivy"org.scala-lang.modules::scala-parser-combinators:1.1.2"
+      )
 
-    object ut extends TestModule {
       override def moduleDeps: Seq[JavaModule] =
-        super.moduleDeps ++ Seq(scalanet.examples)
+        Seq(scalanet, scalanet.discovery)
+
+      object ut extends TestModule {
+        override def moduleDeps: Seq[JavaModule] =
+          super.moduleDeps ++ Seq(scalanet.examples)
+      }
     }
   }
 }

scalanet/discovery/src/io/iohk/scalanet/discovery/ethereum/EthereumNodeRecord.scala

@@ -4,6 +4,7 @@ import scodec.bits.ByteVector
 import scala.collection.SortedMap
 import java.nio.charset.StandardCharsets
 import io.iohk.scalanet.discovery.crypto.{Signature, PrivateKey, SigAlg}
+import io.iohk.scalanet.discovery.util.byteVectorOrdering
 import scodec.{Codec, Attempt}
 import io.iohk.scalanet.discovery.crypto.PublicKey
 import java.net.Inet6Address
@@ -16,8 +17,8 @@ case class EthereumNodeRecord(
 )
 
 object EthereumNodeRecord {
-  implicit val byteOrdering: Ordering[ByteVector] =
-    Ordering.by[ByteVector, Iterable[Byte]](_.toIterable)
+
+  implicit val byteOrdering: Ordering[ByteVector] = byteVectorOrdering
 
   case class Content(
       // Nodes should increment this number whenever their properties change, like their address, and re-publish.

scalanet/discovery/src/io/iohk/scalanet/discovery/ethereum/codecs/DefaultCodecs.scala

@@ -1,6 +1,7 @@
 package io.iohk.scalanet.discovery.ethereum.codecs
 
 import io.iohk.scalanet.discovery.hash.Hash
+import io.iohk.scalanet.discovery.util
 import io.iohk.scalanet.discovery.crypto.{PublicKey, Signature}
 import io.iohk.scalanet.discovery.ethereum.{Node, EthereumNodeRecord}
 import io.iohk.scalanet.discovery.ethereum.v4.Payload
@@ -13,6 +14,7 @@ import scala.collection.SortedMap
 import java.net.InetAddress
 
 object DefaultCodecs {
+
   implicit val publicKeyCodec: Codec[PublicKey] =
     implicitly[Codec[BitVector]].xmap(PublicKey(_), identity)
 
@@ -38,8 +40,7 @@ object DefaultCodecs {
       (sm: SortedMap[K, V]) => sm.toList
     )
 
-  implicit val byteVectorOrdering: Ordering[ByteVector] =
-    Ordering.by[ByteVector, Iterable[Byte]](_.toIterable)
+  implicit val byteVectorOrdering: Ordering[ByteVector] = util.byteVectorOrdering
 
   implicit val attrCodec: Codec[SortedMap[ByteVector, ByteVector]] =
     sortedMapCodec[ByteVector, ByteVector]

scalanet/discovery/src/io/iohk/scalanet/discovery/ethereum/v4/DiscoveryNetwork.scala

@@ -190,15 +190,11 @@ object DiscoveryNetwork {
       private def maybeRespond[Res](maybeResponse: Task[Option[Res]])(
           f: Res => Task[Unit]
       ): Task[Unit] =
-        maybeResponse.attempt.flatMap {
-          case Right(Some(response)) =>
-            f(response)
-          case Right(None) =>
-            Task.unit
-          case Left(NonFatal(ex)) =>
+        maybeResponse.onErrorRecoverWith {
+          case NonFatal(ex) =>
             // Not responding to this one, but it shouldn't stop handling further requests.
-            Task(logger.error(s"Error handling incoming request: $ex"))
-        }
+            Task(logger.error(s"Error handling incoming request: $ex")).as(None)
+        }.flatMap(_.fold(Task.unit)(f))
 
       /** Serialize the payload to binary and sign the packet. */
       private def pack(payload: Payload): Task[Packet] =
@@ -385,6 +381,10 @@ object DiscoveryNetwork {
                 // New response, fold it with the existing to decide if we need more.
                 val next = (acc: Z) => Some(acc -> (count + 1))
                 Task.pure(f(acc, response).bimap(next, next))
+
+              case _ => 
+                // Invalid state - this cannot happen
+                Task.raiseError(new IllegalStateException(s"Unexpected state while collecting responses from ${channel.to}"))
             }
             .map(_.map(_._1))
 
@@ -404,7 +404,7 @@ object DiscoveryNetwork {
     )
     val expiration = System.currentTimeMillis
 
-    Stream
+    Iterator
       .iterate(List(sampleNode))(sampleNode :: _)
       .map { nodes =>
         val payload = Neighbors(nodes, expiration)