Crossbuild for Scala3 (#430)

Co-authored-by: Dejan Mijić <[email protected]>

.github/workflows/ci.yml

@@ -50,7 +50,7 @@ jobs:
       fail-fast: false
       matrix:
         java: ['[email protected]', '[email protected]']
-        scala: ['2.12.14', '2.13.6']
+        scala: ['2.12.15', '2.13.6', '3.0.2']
     steps:
       - name: Checkout current branch
         uses: actions/[email protected]
@@ -64,6 +64,9 @@ jobs:
         uses: coursier/cache-action@v6
       - name: Run tests
         run: sbt ++${{ matrix.scala }}! test
+      - name: Compile examples
+        if: ${{ startsWith(matrix.scala, '2') }}
+        run: ./sbt ++${{ matrix.scala }}! compileExamples
 
   ci:
     runs-on: ubuntu-20.04

build.sbt

@@ -36,12 +36,13 @@ Global / testFrameworks       := Seq(new TestFramework("zio.test.sbt.ZTestFramew
 
 addCommandAlias("fmt", "all scalafmtSbt scalafmt test:scalafmt")
 addCommandAlias("check", "all scalafmtSbtCheck scalafmtCheck test:scalafmtCheck")
+addCommandAlias("compileExamples", "opentracingExample/compile;opentelemetryExample/compile")
 
 lazy val root =
   project
     .in(file("."))
     .settings(publish / skip := true)
-    .aggregate(opentracing, opentelemetry, opencensus, opentracingExample, opentelemetryExample)
+    .aggregate(opentracing, opentelemetry, opencensus)
 
 lazy val opentracing        =
   project
@@ -65,6 +66,7 @@ lazy val opentracingExample =
     .in(file("opentracing-example"))
     .settings(stdSettings("opentracing-example"))
     .settings(publish / skip := true)
+    .settings(onlyWithScala2)
     .settings(libraryDependencies := Dependencies.opentracingExample)
     .dependsOn(opentracing)
 
@@ -73,6 +75,7 @@ lazy val opentelemetryExample =
     .in(file("opentelemetry-example"))
     .settings(stdSettings("opentelemetry-example"))
     .settings(publish / skip := true)
+    .settings(onlyWithScala2)
     .settings(libraryDependencies := Dependencies.opentelemetryExample)
     .dependsOn(opentelemetry)
 

opentracing/src/test/scala/zio/telemetry/opentracing/OpenTracingTest.scala

@@ -20,7 +20,7 @@ object OpenTracingTest extends DefaultRunnableSpec {
     ZLayer.fromEffect(UIO(new MockTracer))
 
   val testService: URLayer[HasMockTracer with Clock, OpenTracing] =
-    ZLayer.fromServiceManaged(tracer => OpenTracing.managed(tracer, "ROOT"))
+    ZLayer.fromServiceManaged((tracer: MockTracer) => OpenTracing.managed(tracer, "ROOT"))
 
   val customLayer = mockTracer ++ ((mockTracer ++ Clock.any) >>> testService)
 

project/BuildHelper.scala

@@ -5,13 +5,17 @@ object BuildHelper {
 
   def stdSettings(prjName: String) = Seq(
     name                     := s"$prjName",
-    crossScalaVersions       := Seq(Scala212, Scala213),
+    crossScalaVersions       := Seq(Scala212, Scala213, Scala3),
     ThisBuild / scalaVersion := Scala212,
     scalacOptions            := stdOptions ++ extraOptions(scalaVersion.value, optimize = !isSnapshot.value),
     libraryDependencies += compilerPlugin("com.olegpy" %% "better-monadic-for" % "0.3.1"),
     incOptions ~= (_.withLogRecompileOnMacro(false))
   )
 
+  val onlyWithScala2 = Seq(
+    crossScalaVersions := Seq(Scala212, Scala213)
+  )
+
   private val versions: Map[String, String] = {
     import org.snakeyaml.engine.v2.api.{ Load, LoadSettings }
 
@@ -27,15 +31,21 @@ object BuildHelper {
 
   private val Scala212: String = versions("2.12")
   private val Scala213: String = versions("2.13")
+  private val Scala3: String   = versions("3.0")
 
   private val stdOptions = Seq(
     "-deprecation",
     "-encoding",
     "UTF-8",
     "-feature",
-    "-unchecked",
-    "-Xfatal-warnings"
-  )
+    "-unchecked"
+  ) ++ {
+    if (sys.env.contains("CI")) {
+      Seq("-Xfatal-warnings")
+    } else {
+      Nil // to enable Scalafix locally
+    }
+  }
 
   private val std2xOptions = Seq(
     "-language:higherKinds",
@@ -52,6 +62,12 @@ object BuildHelper {
 
   private def extraOptions(scalaVersion: String, optimize: Boolean) =
     CrossVersion.partialVersion(scalaVersion) match {
+      case Some((3, _)) =>
+        Seq(
+          "-language:implicitConversions",
+          "-Xignore-scala2-macros"
+        )
+
       case Some((2, 13)) =>
         Seq("-Ywarn-unused:params,-implicits", "-Xlint:-byname-implicit") ++ std2xOptions ++ optimizerOptions(optimize)
 
@@ -74,7 +90,6 @@ object BuildHelper {
           "242"
         ) ++ std2xOptions ++ optimizerOptions(optimize)
 
-      case _ =>
-        Seq.empty
+      case _ => Seq.empty
     }
 }

project/Dependencies.scala

@@ -25,7 +25,7 @@ object Dependencies {
     "io.opentracing"          % "opentracing-api"         % Versions.opentracing,
     "io.opentracing"          % "opentracing-noop"        % Versions.opentracing,
     "io.opentracing"          % "opentracing-mock"        % Versions.opentracing % Test,
-    "org.scala-lang.modules" %% "scala-collection-compat" % "2.3.1"
+    "org.scala-lang.modules" %% "scala-collection-compat" % "2.5.0"
   )
 
   lazy val opentelemetry = zio ++ Seq(