mill init: Gradle Kotlin Support & Refactor

libs/init/buildgen/api/src/mill/main/buildgen/ModuleSpec.scala

@@ -73,7 +73,10 @@ case class ModuleSpec(
     children: Seq[ModuleSpec] = Nil,
     quarkusPlatformVersion: Value[String] = Value(),
     annotationProcessorsMvnDeps: Values[MvnDep] = Values(),
-    artifactGroupId: Value[String] = Value()
+    artifactGroupId: Value[String] = Value(),
+    kotlinVersion: Value[String] = Value(),
+    kotlincOptions: Values[Opt] = Values(),
+    kotlincPluginMvnDeps: Values[MvnDep] = Values()
 ) {
 
   def isBomModule: Boolean = supertypes.contains("BomModule")
@@ -340,7 +343,8 @@ object ModuleSpec {
       mvnDeps.iterator.map(dep => dep.organization -> dep.name).collectFirst {
         case ("org.testng", _) => "TestModule.TestNg"
         case ("junit", _) => "TestModule.Junit4"
-        case ("org.junit.jupiter", _) | ("org.springframework.boot", "spring-boot-starter-test") =>
+        case ("org.junit.jupiter", _) | ("org.springframework.boot", "spring-boot-starter-test") |
+            ("org.jetbrains.kotlin", "kotlin-test" | "kotlin-test-junit5") =>
           "TestModule.Junit5"
         case ("com.lihaoyi", "utest") => "TestModule.Utest"
         case ("org.typelevel", "weaver-cats") => "TestModule.Weaver"

libs/init/buildgen/src/mill/main/buildgen/BuildGen.scala

@@ -102,7 +102,10 @@ trait BuildGen {
         mimaReportSignatureProblems =
           parentValue(a.mimaReportSignatureProblems, b.mimaReportSignatureProblems),
         annotationProcessorsMvnDeps =
-          parentValues(a.annotationProcessorsMvnDeps, b.annotationProcessorsMvnDeps)
+          parentValues(a.annotationProcessorsMvnDeps, b.annotationProcessorsMvnDeps),
+        kotlinVersion = parentValue(a.kotlinVersion, b.kotlinVersion),
+        kotlincOptions = parentValues(a.kotlincOptions, b.kotlincOptions),
+        kotlincPluginMvnDeps = parentValues(a.kotlincPluginMvnDeps, b.kotlincPluginMvnDeps)
       )
 
     def extendValue[A](a: Value[A], parent: Value[A]) = a.copy(
@@ -178,7 +181,10 @@ trait BuildGen {
       mimaReportSignatureProblems =
         extendValue(a.mimaReportSignatureProblems, parent.mimaReportSignatureProblems),
       annotationProcessorsMvnDeps =
-        extendValues(a.annotationProcessorsMvnDeps, parent.annotationProcessorsMvnDeps)
+        extendValues(a.annotationProcessorsMvnDeps, parent.annotationProcessorsMvnDeps),
+      kotlinVersion = extendValue(a.kotlinVersion, parent.kotlinVersion),
+      kotlincOptions = extendValues(a.kotlincOptions, parent.kotlincOptions),
+      kotlincPluginMvnDeps = extendValues(a.kotlincPluginMvnDeps, parent.kotlincPluginMvnDeps)
     )
 
     val (baseHierarchy, testHierarchy) = baseTestHierarchy.unzip

libs/init/buildgen/src/mill/main/buildgen/BuildGenScala.scala

@@ -181,6 +181,9 @@ object BuildGenScala extends BuildGen {
     lines += renderDefValues("scalacOptions", scalacOptions, encodeLiteralOpt)
     lines += renderDefValues("scalacPluginMvnDeps", scalacPluginMvnDeps, encodeMvnDep)
     lines += renderDefValues("javacOptions", javacOptions, encodeOpt)
+    lines += renderDefValue("kotlinVersion", kotlinVersion, encodeString)
+    lines += renderDefValues("kotlincOptions", kotlincOptions, encodeLiteralOpt)
+    lines += renderDefValues("kotlincPluginMvnDeps", kotlincPluginMvnDeps, encodeMvnDep)
     lines += renderDefValues(
       "sourcesRootFolders",
       sourcesRootFolders,

libs/init/buildgen/src/mill/main/buildgen/BuildGenYaml.scala

@@ -106,6 +106,11 @@ object BuildGenYaml extends BuildGen {
     quarkusPlatformVersion.base.foreach(v =>
       lines += s"""def quarkusPlatformVersion = "$v""""
     )
+    kotlinVersion.base.foreach(v =>
+      lines += s"""def kotlinVersion = "$v""""
+    )
+    renderScalaOptValues("def kotlincOptions", kotlincOptions).foreach(lines += _)
+    renderScalaMvnDepValues("def kotlincPluginMvnDeps", kotlincPluginMvnDeps).foreach(lines += _)
 
     artifactName.base.foreach(v => lines += s"def artifactName = $v")
 
@@ -242,6 +247,12 @@ object BuildGenYaml extends BuildGen {
       "quarkusPlatformVersion",
       quarkusPlatformVersion
     ).foreach(lines += _)
+    renderYamlStringValue(
+      "kotlinVersion",
+      kotlinVersion
+    ).foreach(lines += _)
+    renderYamlStringListValues("kotlincOptions", kotlincOptions).foreach(lines += _)
+    renderYamlMvnDepsList("kotlincPluginMvnDeps", kotlincPluginMvnDeps).foreach(lines += _)
 
     renderYamlStringValue(
       "artifactGroupId",