build and test against scala 3.8.0

Author: bjaglin

.github/workflows/ci.yml

@@ -43,6 +43,7 @@ jobs:
       - uses: coursier/setup-action@v1
         with:
           apps: sbt
+          jvm: zulu:17 # for scala 3.8+
       - run: ./bin/scalafmt --test
       - run: sbt "dogfoodScalafixInterfaces; scalafixAll --check"
   mima:
@@ -55,4 +56,5 @@ jobs:
       - uses: coursier/setup-action@v1
         with:
           apps: sbt
+          jvm: zulu:17 # for scala 3.8+
       - run: sbt versionPolicyCheck

.github/workflows/release.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: coursier/setup-action@v1
         with:
           apps: sbt
-          jvm: temurin:8
+          jvm: temurin:17 # TODO: check the bytecode format for scala <3.8
       - uses: olafurpg/setup-gpg@v3
       - name: Check that major or minor was bumped upon compatibility breakage
         if: startsWith(github.ref, 'refs/tags/v')

bin/test-release.sh

@@ -6,7 +6,7 @@ version=$1
 scala212=2.12.20
 scala213=2.13.17
 scala3LTS=3.3.7
-scala3Next=3.7.4
+scala3Next=3.8.0
 
 cs resolve \
   ch.epfl.scala:scalafix-interfaces:$version  \

build.sbt

@@ -36,6 +36,7 @@ lazy val interfaces = project
       props.put("scala35", scala35)
       props.put("scala36", scala36)
       props.put("scala37", scala37)
+      props.put("scala38", scala38)
       props.put("scala3LTS", scala3LTS)
       props.put("scala3Next", scala3Next)
       val out =

project/Dependencies.scala

@@ -12,8 +12,9 @@ object Dependencies {
   val scala35 = "3.5.2"
   val scala36 = "3.6.4"
   val scala37 = "3.7.4"
+  val scala38 = "3.8.0-RC1"
   val scala3LTS = scala33
-  val scala3Next = sys.props.getOrElse("scala3.nightly", scala37)
+  val scala3Next = sys.props.getOrElse("scala3.nightly", scala38)
 
   val bijectionCoreV = "0.9.8"
   val collectionCompatV = "2.14.0"

project/Mima.scala

@@ -7,8 +7,9 @@ object Mima {
     // See https://github.com/lightbend/mima
     Seq(
       ProblemFilters.exclude[Problem]("scalafix.internal.*"),
-      ProblemFilters.exclude[Problem]("scala.meta.internal.*")
+      ProblemFilters.exclude[Problem]("scala.meta.internal.*"),
       // Exceptions
+      ProblemFilters.exclude[ReversedMissingMethodProblem]("scalafix.interfaces.Scalafix.scala38")
     )
   }
 }

project/ScalafixBuild.scala

@@ -34,16 +34,17 @@ object ScalafixBuild extends AutoPlugin with GhpagesKeys {
     // https://github.com/scalameta/scalameta/issues/2485
     lazy val coreScalaVersions = Seq(scala212, scala213)
     lazy val cliScalaVersions = {
-      val scala3Versions = Seq(scala33, scala35, scala36, scala37)
+      val scala3Versions = Seq(scala33, scala35, scala36, scala37, scala38)
       val jdk = System.getProperty("java.specification.version").toDouble
       val unsupportedVersions =
         if (jdk >= 25) Seq(scala212, scala35, scala36)
+        else if (jdk < 17) Seq(scala38)
         else Nil
       (coreScalaVersions ++ scala3Versions :+ scala3Next)
         .diff(unsupportedVersions)
     }
     lazy val cliScalaVersionsWithTargets: Seq[(String, TargetAxis)] =
-      cliScalaVersions.map(sv => (sv, TargetAxis(sv))) ++
+      cliScalaVersions.map(sv => (sv, TargetAxis(sv))) ++ {
         cliScalaVersions.intersect(Seq(scala213, scala212)).flatMap { sv =>
           def previousVersions(scalaVersion: String): Seq[String] = {
             val split = scalaVersion.split('.')
@@ -66,6 +67,10 @@ object ScalafixBuild extends AutoPlugin with GhpagesKeys {
           (scala3Next, TargetAxis(scala213)),
           (scala3Next, TargetAxis(scala3LTS))
         )
+      }.filter { case (sv, target) =>
+        val jdk = System.getProperty("java.specification.version").toDouble
+        jdk >= 17 || (sv != scala38 && target.scalaVersion != scala38)
+      }
 
     lazy val publishLocalTransitive =
       taskKey[Unit]("Run publishLocal on this project and its dependencies")
@@ -85,16 +90,21 @@ object ScalafixBuild extends AutoPlugin with GhpagesKeys {
       scalaVersion.value.startsWith("2.12")
     }
     lazy val warnUnused = Def.setting {
-      if (isScala3.value)
+      val minor = scalaVersion.value.split('.')(1).toInt
+      if (isScala3.value && minor >= 7)
+        Seq("-Wunused:all")
+      else if (isScala3.value)
         Seq(
           "-Wunused:all",
-          "-Wunused:unsafe-warn-patvars" // only needed for <3.7.0
+          "-Wunused:unsafe-warn-patvars"
         )
       else if (isScala213.value) Seq("-Wunused")
       else Seq("-Ywarn-unused")
     }
     lazy val targetJvm = Def.setting {
-      if (isScala3.value) Seq("-release:8")
+      val minor = scalaVersion.value.split('.')(1).toInt
+      if (isScala3.value && minor >= 8) Seq("-release:17")
+      else if (isScala3.value) Seq("-release:8")
       else if (isScala213.value) Seq("-release", "8")
       else Seq("-target:jvm-1.8")
     }
@@ -150,6 +160,7 @@ object ScalafixBuild extends AutoPlugin with GhpagesKeys {
         "scala35" -> scala35,
         "scala36" -> scala36,
         "scala37" -> scala37,
+        "scala38" -> scala38,
         "scala3LTS" -> scala3LTS,
         "scala3Next" -> scala3Next,
         sbtVersion
@@ -241,7 +252,8 @@ object ScalafixBuild extends AutoPlugin with GhpagesKeys {
   )
 
   private val PreviousScalaVersion: Map[String, Option[String]] = Map(
-    scala37 -> Some("3.7.3")
+    scala37 -> Some("3.7.3"),
+    scala38 -> None
   )
 
   override def buildSettings: Seq[Setting[_]] = List(

scalafix-cli/src/main/scala/scalafix/internal/interfaces/ScalafixImpl.scala

@@ -42,6 +42,8 @@ final class ScalafixImpl extends Scalafix {
     Versions.scala36
   override def scala37(): String =
     Versions.scala37
+  override def scala38(): String =
+    Versions.scala38
   override def scala3LTS(): String =
     Versions.scala3LTS
   override def scala3Next(): String =

scalafix-interfaces/src/main/java/scalafix/interfaces/Scalafix.java

@@ -90,6 +90,11 @@ public interface Scalafix {
      */
     String scala37();
 
+    /**
+     * The Scala 3.8 version in {@link #supportedScalaVersions()}
+     */
+    String scala38();
+
     /**
      * The Scala 3 LTS version in {@link #supportedScalaVersions()}
      */
@@ -162,6 +167,8 @@ static Scalafix fetchAndClassloadInstance(String requestedScalaVersion, List<Rep
             scalaVersionKey = "scala36";
         } else if (requestedScalaMajorMinorOrMajorVersion.equals("3.7")) {
             scalaVersionKey = "scala37";
+        } else if (requestedScalaMajorMinorOrMajorVersion.equals("3.8")) {
+            scalaVersionKey = "scala38";
         } else if (requestedScalaMajorMinorOrMajorVersion.startsWith("3")) {
             scalaVersionKey = "scala3Next";
         } else {

scalafix-tests/integration/src/test/scala/scalafix/tests/interfaces/ScalafixSuite.scala

@@ -49,6 +49,7 @@ class ScalafixSuite extends AnyFunSuite {
     assert(api.scala35() == Versions.scala35)
     assert(api.scala36() == Versions.scala36)
     assert(api.scala37() == Versions.scala37)
+    assert(api.scala38() == Versions.scala38)
     assert(api.scala3LTS() == Versions.scala3LTS)
     assert(api.scala3Next() == Versions.scala3Next)
     assert(
@@ -134,12 +135,12 @@ class ScalafixSuite extends AnyFunSuite {
   }
 
   test("classload Scala 3 Next with full version") {
-    val scalafixAPI = Scalafix.fetchAndClassloadInstance("3.7.0", repositories)
+    val scalafixAPI = Scalafix.fetchAndClassloadInstance("3.8.0", repositories)
     assert(scalafixAPI.scalaVersion() == Versions.scala3Next)
   }
 
   test("classload Scala 3 Next with major.minor version") {
-    val scalafixAPI = Scalafix.fetchAndClassloadInstance("3.7", repositories)
+    val scalafixAPI = Scalafix.fetchAndClassloadInstance("3.8", repositories)
     assert(scalafixAPI.scalaVersion() == Versions.scala3Next)
   }