Cross compile to Scala 3.0.0-M1

Author: gaeljw

build.sbt

@@ -22,6 +22,7 @@ ThisBuild / homepage := Some(url("https://github.com/cucumber/cucumber-jvm-scala
 val scala211 = "2.11.12"
 val scala212 = "2.12.12"
 val scala213 = "2.13.3"
+val scala3 = "3.0.0-M1"
 
 scalaVersion := scala213
 
@@ -42,9 +43,11 @@ lazy val commonSettings = Seq(
       case Some((2, 11)) => ScalacOptions.scalacOptions211
       case Some((2, 12)) => ScalacOptions.scalacOptions212
       case Some((2, 13)) => ScalacOptions.scalacOptions213
+      case Some((3, 0)) => ScalacOptions.scalacOptions3
       case _ => Seq()
     }
   },
+  scalacOptions ++= { if (isDotty.value) Seq("-source:3.0-migration") else Nil }
 )
 
 lazy val root = (project in file("."))
@@ -67,11 +70,11 @@ lazy val cucumberScala = (projectMatrix in file("cucumber-scala"))
 
       // Users have to provide it (for JacksonDefaultDataTableTransformer)
       "com.fasterxml.jackson.core" % "jackson-databind" % jacksonVersion % Provided,
-      "com.fasterxml.jackson.module" %% "jackson-module-scala" % jacksonVersion % Provided,
+      ("com.fasterxml.jackson.module" %% "jackson-module-scala" % jacksonVersion % Provided).withDottyCompat(scalaVersion.value),
 
       "junit" % "junit" % junitVersion % Test,
       "io.cucumber" % "cucumber-junit" % cucumberVersion % Test,
-      "org.mockito" %% "mockito-scala" % mockitoScalaVersion % Test
+      ("org.mockito" %% "mockito-scala" % mockitoScalaVersion % Test).withDottyCompat(scalaVersion.value)
     ),
     libraryDependencies ++= {
       CrossVersion.partialVersion(scalaVersion.value) match {
@@ -93,7 +96,7 @@ lazy val cucumberScala = (projectMatrix in file("cucumber-scala"))
       Seq(file)
     }.taskValue
   )
-  .jvmPlatform(scalaVersions = Seq(scala213, scala212, scala211))
+  .jvmPlatform(scalaVersions = Seq(scala3, scala213, scala212, scala211))
 
 // Examples project
 lazy val examples = (projectMatrix in file("examples"))
@@ -107,7 +110,7 @@ lazy val examples = (projectMatrix in file("examples"))
     publishArtifact := false
   )
   .dependsOn(cucumberScala % Test)
-  .jvmPlatform(scalaVersions = Seq(scala213, scala212))
+  .jvmPlatform(scalaVersions = Seq(scala3, scala213, scala212))
 
 // Release & Publish
 

cucumber-scala/src/main/scala/io/cucumber/scala/GlueAdaptor.scala

@@ -13,7 +13,7 @@ class GlueAdaptor(glue: Glue) {
   def loadRegistry(registry: ScalaDslRegistry, scenarioScoped: Boolean): Unit = {
 
     // If the registry is not consistent, this indicates a mistake in the users definition and we want to let him know.
-    registry.checkConsistency().left.foreach { ex: IncorrectHookDefinitionException =>
+    registry.checkConsistency().left.foreach { (ex: IncorrectHookDefinitionException) =>
       throw ex
     }
 

cucumber-scala/src/main/scala/io/cucumber/scala/Implicits.scala

@@ -32,7 +32,7 @@ object Implicits {
     def asScalaMaps[K, V](implicit evK: ClassTag[K], evV: ClassTag[V]): Seq[Map[K, Option[V]]] = {
       table.asMaps[K, V](evK.runtimeClass, evV.runtimeClass)
         .asScala
-        .map(_.asScala.map(nullToNone).toMap)
+        .map(_.asScala.map(nullToNone(_)).toMap)
         .toSeq
     }
 
@@ -72,7 +72,7 @@ object Implicits {
     def asScalaMap[K, V](implicit evK: ClassTag[K], evV: ClassTag[V]): Map[K, Option[V]] = {
       table.asMap[K, V](evK.runtimeClass, evV.runtimeClass)
         .asScala
-        .map(nullToNone)
+        .map(nullToNone(_))
         .toMap
     }
 
@@ -165,7 +165,7 @@ object Implicits {
     def asScalaRowColumnMap[K](implicit evK: ClassTag[K]): Map[K, Map[String, Option[String]]] = {
       table.asMap[K, java.util.Map[String, String]](evK.runtimeClass, classOf[java.util.Map[String, String]])
         .asScala
-        .map { case (k, v) => (k, v.asScala.map(nullToNone).toMap) }
+        .map { case (k, v) => (k, v.asScala.map(nullToNone(_)).toMap) }
         .toMap
     }
 

cucumber-scala/src/main/scala/io/cucumber/scala/ScalaDsl.scala

@@ -2,6 +2,7 @@ package io.cucumber.scala
 
 import Aliases._
 
+import scala.annotation.nowarn
 import scala.reflect.ClassTag
 
 private[scala] trait BaseScalaDsl {
@@ -521,7 +522,8 @@ private[scala] trait StepDsl extends BaseScalaDsl {
       *
       **/
     def apply(f: => Unit): Unit = {
-      apply(() => f)
+      val fun0 = () => f
+      apply(fun0)
     }
 
     def apply(fun: Fun0): Unit = {

examples/src/main/scala/cucumber/examples/scalacalculator/RpnCalculator.scala

@@ -6,8 +6,8 @@ import scala.collection.mutable.Queue
 sealed trait Arg
 
 object Arg{
-  implicit def op(s:String) = Op(s)
-  implicit def value(v:Double) = Val(v)
+  implicit def op(s:String): Op = Op(s)
+  implicit def value(v:Double): Val = Val(v)
 }
 
 case class Op(value: String) extends Arg

project/I18nGenerator.scala

@@ -10,7 +10,7 @@ object I18nGenerator {
 
   private def keywordVal(kw: String): String = {
     val keyworkValName = java.text.Normalizer.normalize(kw.replaceAll("[\\s',!]", ""), java.text.Normalizer.Form.NFC)
-    s"""val $keyworkValName = new Step("$keyworkValName")"""
+    s"""\tval $keyworkValName = new Step("$keyworkValName")"""
   }
 
   private def traitCode(language: String): String = {

project/ScalacOptions.scala

@@ -1,5 +1,19 @@
 object ScalacOptions {
 
+  val scalacOptions3 = Seq(
+    "-rewrite",
+    "-deprecation", // Emit warning and location for usages of deprecated APIs.
+    "-explain", // Explain type errors in more detail.
+//    "-explaintypes", // 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.
+    "-Xfatal-warnings" // Fail the compilation if there are any warnings.
+  )
+
   // Source: https://nathankleyn.com/2019/05/13/recommended-scalac-flags-for-2-13/
   val scalacOptions213 = Seq(
     "-deprecation", // Emit warning and location for usages of deprecated APIs.
@@ -39,7 +53,7 @@ object ScalacOptions {
     "-Ywarn-value-discard", // Warn when non-Unit expression results are unused.
     "-Ybackend-parallelism", "8", // Enable paralellisation — change to desired number!
     "-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.
+    "-Ycache-macro-class-loader:last-modified" // and macro definitions. This can lead to performance improvements.
   )
 
   val scalacOptions212 = Seq(

project/plugins.sbt

@@ -1,6 +1,9 @@
 // Cross compilation matrix
 addSbtPlugin("com.eed3si9n" % "sbt-projectmatrix" % "0.6.0")
 
+// Scala 3 (Dotty)
+addSbtPlugin("ch.epfl.lamp" % "sbt-dotty" % "0.4.6")
+
 // Release
 addSbtPlugin("com.github.gseitz" % "sbt-release" % "1.0.13")