Use & for Scala 3

build.sbt

@@ -69,8 +69,8 @@ lazy val plugin = (project in file("plugin"))
     crossScalaVersions := Seq(scala212, scala3),
     pluginCrossBuild / sbtVersion := {
       scalaBinaryVersion.value match {
-        case "2.13" => "1.2.8"
-        case "2.12" => "1.2.8" // set minimum sbt version
+        case "2.13" => "1.5.8"
+        case "2.12" => "1.5.8" // set minimum sbt version
         case _      => "2.0.0-M2"
       }
     },

library/src/main/scala/sbt/contraband/CodecCodeGen.scala

@@ -20,7 +20,8 @@ class CodecCodeGen(
     javaOption: String,
     scalaArray: String,
     formatsForType: ast.Type => List[String],
-    includedSchemas: List[Document]
+    includedSchemas: List[Document],
+    scalaVersion: String,
 ) extends CodeGenerator {
   import CodecCodeGen._
 
@@ -36,6 +37,8 @@ class CodecCodeGen(
     override def exitMultilineJavadoc(s: String) = s == "*/"
   }
 
+  private def intersection: String = ScalaCodeGen.intersection(scalaVersion)
+
   override def generateEnum(s: Document, e: EnumTypeDefinition): ListMap[File, String] = {
     val fqn = fullyQualifiedName(e)
     // Java enum can have additional parameter such as MERCURY (3.303e+23, 2.4397e6)
@@ -168,7 +171,7 @@ class CodecCodeGen(
           val rfs = getAllRequiredFormats(s, i).distinct filter { _ != fmt }
           val selfType = rfs match {
             case Nil => ""
-            case fms => fms.mkString("self: ", " with ", " =>")
+            case fms => fms.mkString("self: ", intersection, " =>")
           }
           val typeFieldName = (toCodecTypeField(i.directives) orElse toCodecTypeField(s)).getOrElse("type")
           val flatUnionFormat =
@@ -301,7 +304,7 @@ class CodecCodeGen(
   private def makeSelfType(s: Document, d: TypeDefinition): String =
     getRequiredFormats(s, d).distinct match {
       case Nil => ""
-      case fms => fms.mkString("self: ", " with ", " =>")
+      case fms => fms.mkString("self: ", intersection, " =>")
     }
 
   private def genPackage(s: Document): String =

library/src/main/scala/sbt/contraband/MixedCodeGen.scala

@@ -16,7 +16,8 @@ class MixedCodeGen(
     genScalaFileName: Any => File,
     scalaSealProtocols: Boolean,
     scalaPrivateConstructor: Boolean,
-    wrapOption: Boolean
+    wrapOption: Boolean,
+    scalaVersion: String,
 ) extends CodeGenerator {
   val javaGen = new JavaCodeGen(javaLazy, javaOptional, instantiateJavaOptional, wrapOption)
   val scalaGen = new ScalaCodeGen(
@@ -27,7 +28,8 @@ class MixedCodeGen(
     genScalaFileName,
     scalaSealProtocols,
     scalaPrivateConstructor,
-    wrapOption
+    wrapOption,
+    scalaVersion,
   )
 
   def generate(s: Document): ListMap[File, String] =

library/src/main/scala/sbt/contraband/ScalaCodeGen.scala

@@ -17,7 +17,8 @@ class ScalaCodeGen(
     genFile: Any => File,
     scalaSealProtocols: Boolean,
     scalaPrivateConstructor: Boolean,
-    wrapOption: Boolean
+    wrapOption: Boolean,
+    scalaVersion: String,
 ) extends CodeGenerator {
 
   implicit object indentationConfiguration extends IndentationConfiguration {
@@ -30,6 +31,7 @@ class ScalaCodeGen(
     override def enterMultilineJavadoc(s: String) = s == "/**"
     override def exitMultilineJavadoc(s: String) = s == "*/"
   }
+  def intersection: String = ScalaCodeGen.intersection(scalaVersion)
 
   override def generate(s: Document): ListMap[File, String] =
     (s.definitions collect { case td: TypeDefinition =>
@@ -176,12 +178,12 @@ class ScalaCodeGen(
   private def genExtendsCode(parent: Option[InterfaceTypeDefinition], extraParents: List[String], superCtorArguments: String): String = {
     val parentInterface = parent.map(p => s"${fullyQualifiedName(p)}($superCtorArguments)")
     val allParents = parentInterface.toList ::: extraParents ::: List("Serializable")
-    val extendsCode = allParents.mkString(" with ")
+    val extendsCode = allParents.mkString(intersection)
     if (extendsCode == "") "" else s"extends $extendsCode"
   }
 
   private def genExtendsCodeCompanion(companion: List[String]): String = {
-    val extendsCodeCompanion = companion.mkString(" with ")
+    val extendsCodeCompanion = companion.mkString(intersection)
     if (extendsCodeCompanion == "") "" else s" extends $extendsCodeCompanion"
   }
 
@@ -482,3 +484,9 @@ class ScalaCodeGen(
     } mkString (EOL + EOL)
   }
 }
+
+object ScalaCodeGen {
+  def intersection(scalaVersion: String): String =
+    if (scalaVersion.startsWith("2.")) " with "
+    else " & "
+}

library/src/test/scala/GraphQLCodecCodeGenSpec.scala

@@ -22,7 +22,7 @@ object GraphQLCodecCodeGenSpec extends BasicTestSuite with EqualLines {
         |
         |import _root_.sjsonnew.JsonFormat
         |
-        |trait InterfaceExampleFormats { self: sjsonnew.BasicJsonProtocol with generated.ChildTypeFormats =>
+        |trait InterfaceExampleFormats { self: sjsonnew.BasicJsonProtocol & generated.ChildTypeFormats =>
         |  implicit lazy val InterfaceExampleFormat: JsonFormat[com.example.InterfaceExample] = flatUnionFormat1[com.example.InterfaceExample, com.example.ChildType]("type")
         |}""".stripMargin.stripSpace
     )
@@ -78,7 +78,7 @@ object GraphQLCodecCodeGenSpec extends BasicTestSuite with EqualLines {
         |
         |import _root_.sjsonnew.JsonFormat
         |
-        |trait InterfaceExampleFormats { self: sjsonnew.BasicJsonProtocol with generated.ChildTypeFormats =>
+        |trait InterfaceExampleFormats { self: sjsonnew.BasicJsonProtocol & generated.ChildTypeFormats =>
         |  implicit lazy val InterfaceExampleFormat: JsonFormat[com.example.InterfaceExample] = flatUnionFormat1[com.example.InterfaceExample, com.example.ChildType]("type")
         |}""".stripMargin.stripSpace
     )
@@ -136,7 +136,7 @@ object GraphQLCodecCodeGenSpec extends BasicTestSuite with EqualLines {
         |
         |import _root_.sjsonnew.JsonFormat
         |
-        |trait InterfaceExampleFormats { self: generated.TestItemDetailFormats with com.example.StatusFormats with sjsonnew.BasicJsonProtocol with generated.ChildTypeFormats =>
+        |trait InterfaceExampleFormats { self: generated.TestItemDetailFormats & com.example.StatusFormats & sjsonnew.BasicJsonProtocol & generated.ChildTypeFormats =>
         |  implicit lazy val InterfaceExampleFormat: JsonFormat[com.example.InterfaceExample] = flatUnionFormat1[com.example.InterfaceExample, com.example.ChildType]("type")
         |}""".stripMargin.stripSpace
     )
@@ -153,7 +153,16 @@ object GraphQLCodecCodeGenSpec extends BasicTestSuite with EqualLines {
       case other =>
         CodecCodeGen.formatsForType(other)
     }
+  val scalaVersion = "3.5.1"
 
   def mkCodecCodeGen: CodecCodeGen =
-    new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil)
+    new CodecCodeGen(
+      codecParents = codecParents,
+      instantiateJavaLazy = instantiateJavaLazy,
+      javaOption = javaOption,
+      scalaArray = scalaArray,
+      formatsForType = formatsForType,
+      includedSchemas = Nil,
+      scalaVersion = scalaVersion,
+    )
 }

library/src/test/scala/GraphQLMixedCodeGenSpec.scala

@@ -13,6 +13,7 @@ class GraphQLMixedCodeGenSpec extends AnyFlatSpec with Matchers with Inside with
   "generate(Record)" should "handle mixed Java-Scala inheritance" in {
     val Success(ast) = SchemaParser.parse(mixedExample)
     // println(ast)
+    val scalaVersion = "2.13.15"
     val gen = new MixedCodeGen(
       javaLazy,
       CodeGen.javaOptional,
@@ -21,7 +22,8 @@ class GraphQLMixedCodeGenSpec extends AnyFlatSpec with Matchers with Inside with
       genFileName,
       scalaSealProtocols = true,
       scalaPrivateConstructor = true,
-      wrapOption = true
+      wrapOption = true,
+      scalaVersion = scalaVersion,
     )
     val code = gen.generate(ast)
 

library/src/test/scala/GraphQLScalaCodeGenSpec.scala

@@ -81,7 +81,7 @@ object GraphQLScalaCodeGenSpec extends BasicTestSuite with EqualLines {
         |* @param field something
         |*/
         |final class TypeExample private (
-        |val field: Option[java.net.URL]) extends Intf1 with Serializable {
+        |val field: Option[java.net.URL]) extends Intf1 & Serializable {
         |  override def equals(o: Any): Boolean = this.eq(o.asInstanceOf[AnyRef]) || (o match {
         |    case x: TypeExample => (this.field == x.field)
         |    case _ => false
@@ -288,7 +288,7 @@ object GraphQLScalaCodeGenSpec extends BasicTestSuite with EqualLines {
         |}
         |final class ChildType private (
         |  val name: Option[String],
-        |  field: Option[Int]) extends com.example.InterfaceExample(field) with Serializable {
+        |  field: Option[Int]) extends com.example.InterfaceExample(field) & Serializable {
         |  override def equals(o: Any): Boolean = this.eq(o.asInstanceOf[AnyRef]) || (o match {
         |    case x: ChildType => (this.name == x.name) && (this.field == x.field)
         |    case _ => false
@@ -365,7 +365,7 @@ object GraphQLScalaCodeGenSpec extends BasicTestSuite with EqualLines {
       """package com.example
         |/** Example of an interface */
         |sealed abstract class IntfExample(
-        |  val field: Option[Int]) extends Interface1 with Interface2 with Serializable {
+        |  val field: Option[Int]) extends Interface1 & Interface2 & Serializable {
         |  // Some extra code...
         |  override def equals(o: Any): Boolean = this.eq(o.asInstanceOf[AnyRef]) || (o match {
         |    case x: IntfExample => (this.field == x.field)
@@ -379,13 +379,14 @@ object GraphQLScalaCodeGenSpec extends BasicTestSuite with EqualLines {
         |  }
         |}
         |
-        |object IntfExample extends CompanionInterface1 with CompanionInterface2 {
+        |object IntfExample extends CompanionInterface1 & CompanionInterface2 {
         |  // Some extra companion code...
         |}
         |""".stripMargin.stripSpace
     )
   }
 
+  def scalaVersion: String = "3.5.1"
   def mkScalaCodeGen: ScalaCodeGen =
     new ScalaCodeGen(
       javaLazy,
@@ -395,7 +396,8 @@ object GraphQLScalaCodeGenSpec extends BasicTestSuite with EqualLines {
       genFileName,
       scalaSealProtocols = true,
       scalaPrivateConstructor = true,
-      wrapOption = true
+      wrapOption = true,
+      scalaVersion = scalaVersion,
     )
   val javaLazy = "com.example.Lazy"
   val outputFile = new File("output.scala")

library/src/test/scala/JsonCodecCodeGenSpec.scala

@@ -11,9 +11,10 @@ class JsonCodecCodeGenSpec extends GCodeGenSpec("Codec") {
   val javaOption = "com.example.Option"
   val scalaArray = "Vector"
   val formatsForType: ast.Type => List[String] = CodecCodeGen.formatsForType
+  val scalaVersion = "2.13.15"
 
   override def enumerationGenerateSimple = {
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil, scalaVersion)
     val enumeration = JsonParser.EnumTypeDefinition.parse(simpleEnumerationExample)
     val code = gen generate enumeration
 
@@ -52,7 +53,7 @@ class JsonCodecCodeGenSpec extends GCodeGenSpec("Codec") {
   }
 
   override def interfaceGenerateSimple = {
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil, scalaVersion)
     val intf = JsonParser.InterfaceTypeDefinition.parseInterface(simpleInterfaceExample)
     val code = gen generate intf
 
@@ -78,7 +79,7 @@ class JsonCodecCodeGenSpec extends GCodeGenSpec("Codec") {
   }
 
   override def interfaceGenerateOneChild = {
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil, scalaVersion)
     val intf = JsonParser.InterfaceTypeDefinition.parseInterface(oneChildInterfaceExample)
     val code = gen generate intf
 
@@ -128,7 +129,7 @@ class JsonCodecCodeGenSpec extends GCodeGenSpec("Codec") {
   }
 
   override def interfaceGenerateNested = {
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil, scalaVersion)
     val intf = JsonParser.InterfaceTypeDefinition.parseInterface(nestedInterfaceExample)
     val code = gen generate intf
 
@@ -149,7 +150,7 @@ class JsonCodecCodeGenSpec extends GCodeGenSpec("Codec") {
 
   def interfaceGenerateMessages = {
     val schema = JsonParser.Document.parse(generateArgDocExample)
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil, scalaVersion)
     val code = gen generate schema
 
     code.head._2.unindent should equalLines("""/**
@@ -174,7 +175,7 @@ class JsonCodecCodeGenSpec extends GCodeGenSpec("Codec") {
   }
 
   override def recordGenerateSimple = {
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil, scalaVersion)
     val record = JsonParser.ObjectTypeDefinition.parse(simpleRecordExample)
     val code = gen generate record
 
@@ -210,7 +211,7 @@ class JsonCodecCodeGenSpec extends GCodeGenSpec("Codec") {
   }
 
   override def recordGrowZeroToOneField = {
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil, scalaVersion)
     val record = JsonParser.ObjectTypeDefinition.parse(growableAddOneFieldExample)
     val code = gen generate record
 
@@ -246,7 +247,7 @@ class JsonCodecCodeGenSpec extends GCodeGenSpec("Codec") {
   }
 
   override def recordGrowZeroToOneToTwoFields: Unit = {
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil, scalaVersion)
     val record = JsonParser.ObjectTypeDefinition.parse(growableZeroToOneToTwoFieldsExample)
     val code = gen generate record
 
@@ -284,7 +285,7 @@ class JsonCodecCodeGenSpec extends GCodeGenSpec("Codec") {
   }
 
   override def recordPrimitives: Unit = {
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, Nil, scalaVersion)
     val record = JsonParser.ObjectTypeDefinition.parse(primitiveTypesExample2)
     val code = gen generate record
 
@@ -325,7 +326,7 @@ implicit lazy val primitiveTypesExample2Format: JsonFormat[_root_.primitiveTypes
 
   override def schemaGenerateTypeReferences = {
     val schema = JsonParser.Document.parse(primitiveTypesExample)
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil, scalaVersion)
     val code = gen generate schema
 
     code.head._2.unindent should equalLines("""/**
@@ -371,7 +372,7 @@ implicit lazy val primitiveTypesExample2Format: JsonFormat[_root_.primitiveTypes
 
   override def schemaGenerateTypeReferencesNoLazy = {
     val schema = JsonParser.Document.parse(primitiveTypesNoLazyExample)
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil, scalaVersion)
     val code = gen generate schema
 
     code.head._2.unindent should equalLines("""/**
@@ -408,14 +409,14 @@ implicit lazy val primitiveTypesExample2Format: JsonFormat[_root_.primitiveTypes
 
   override def schemaGenerateComplete = {
     val schema = JsonParser.Document.parse(completeExample)
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil, scalaVersion)
     val code = gen generate schema
     code.values.mkString.unindent should equalLines(completeExampleCodeCodec.unindent)
   }
 
   override def schemaGenerateCompletePlusIndent = {
     val schema = JsonParser.Document.parse(completeExample)
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil, scalaVersion)
     val code = gen generate schema
 
     code.values.mkString.withoutEmptyLines should equalLines(completeExampleCodeCodec.withoutEmptyLines)
@@ -431,7 +432,7 @@ implicit lazy val primitiveTypesExample2Format: JsonFormat[_root_.primitiveTypes
                                  |    }
                                  |  ]
                                  |}""".stripMargin)
-    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil)
+    val gen = new CodecCodeGen(codecParents, instantiateJavaLazy, javaOption, scalaArray, formatsForType, schema :: Nil, scalaVersion)
     val code = gen generate schema
 
     code.head._2.unindent should equalLines("""/**

library/src/test/scala/JsonScalaCodeGenSpec.scala

@@ -466,6 +466,7 @@ object primitiveTypesExample2 {
     code.head._2.withoutEmptyLines should equalLines(completeExampleCodeScala.withoutEmptyLines)
   }
 
+  def scalaVersion: String = "2.13.15"
   def mkScalaCodeGen: ScalaCodeGen =
     new ScalaCodeGen(
       javaLazy,
@@ -475,7 +476,8 @@ object primitiveTypesExample2 {
       genFileName,
       scalaSealProtocols = true,
       scalaPrivateConstructor = true,
-      wrapOption = true
+      wrapOption = true,
+      scalaVersion = scalaVersion,
     )
   val javaLazy = "com.example.Lazy"
   val outputFile = new File("output.scala")