From d7859cac48a777e9b4430b7299b9044c722eb3fa Mon Sep 17 00:00:00 2001
From: Lorenzo Gabriele <lorenzolespaul@gmail.com>
Date: Tue, 7 Nov 2023 15:01:31 +0100
Subject: [PATCH] Support Play Framework 3.0 and 2.9 (#2772)

- Update Play 2.8 to 2.8.20
- Add default `twirlVersion` for play based on `playVersion`
- Add default `twirlScalaVersion` based on `twirlVersion`

Pull request: https://github.com/com-lihaoyi/mill/pull/2772
---
 build.sc                                      |  22 ++-
 .../api/src/mill/playlib/api/Versions.java    |   2 +
 contrib/playlib/readme.adoc                   |  45 +++--
 .../playlib/src/mill/playlib/PlayModule.scala |  14 +-
 .../src/mill/playlib/RouterModule.scala       |   9 +-
 .../playlib/src/mill/playlib/Version.scala    |   8 +-
 .../resources/hello-world/core/routes/routes  |   2 +-
 .../test/resources/invalid/core/routes/routes |   2 +-
 .../resources/invalidsub/core/routes/routes   |   2 +-
 .../test/resources/playmulti/core/conf/routes |   2 +-
 .../test/resources/playsingle/conf/routes     |   2 +-
 .../test/resources/playsingleapi/conf/routes  |   2 +-
 .../src/mill/playlib/PlayModuleTests.scala    |  75 +++++----
 .../playlib/PlaySingleApiModuleTests.scala    |   3 +-
 .../mill/playlib/PlaySingleModuleTests.scala  |   5 +-
 .../test/src/mill/playlib/PlayTestSuite.scala |  19 ++-
 .../src/mill/playlib/RouterModuleTests.scala  | 140 ++++++++--------
 .../playlib/worker/RouteCompilerWorker.scala  |   3 +
 .../playlib/worker/RouteCompilerWorker.scala  |   3 +
 .../src/mill/twirllib/TwirlModule.scala       |  22 ++-
 .../src/mill/twirllib/HelloWorldTests.scala   | 156 ++++++++++--------
 21 files changed, 312 insertions(+), 226 deletions(-)
 create mode 100644 contrib/playlib/worker/2.9/src/mill/playlib/worker/RouteCompilerWorker.scala
 create mode 100644 contrib/playlib/worker/3.0/src/mill/playlib/worker/RouteCompilerWorker.scala

diff --git a/build.sc b/build.sc
index 34dd901eecd..f20ab37e308 100644
--- a/build.sc
+++ b/build.sc
@@ -61,6 +61,7 @@ object Deps {
   val testScala30Version = "3.0.2"
   val testScala31Version = "3.1.3"
   val testScala32Version = "3.2.0"
+  val testScala33Version = "3.3.1"
 
   object Scalajs_1 {
     val scalaJsVersion = "1.14.0"
@@ -84,7 +85,11 @@ object Deps {
   trait Play {
     def playVersion: String
     def playBinVersion: String = playVersion.split("[.]").take(2).mkString(".")
-    def routesCompiler = ivy"com.typesafe.play::routes-compiler::$playVersion"
+    def routesCompiler = playBinVersion match {
+      case "2.6" | "2.7" | "2.8" => ivy"com.typesafe.play::routes-compiler::$playVersion"
+      case "2.9" => ivy"com.typesafe.play::play-routes-compiler::$playVersion"
+      case _ => ivy"org.playframework::play-routes-compiler::$playVersion"
+    }
     def scalaVersion: String = Deps.scalaVersion
   }
   object Play_2_6 extends Play {
@@ -95,9 +100,15 @@ object Deps {
     val playVersion = "2.7.9"
   }
   object Play_2_8 extends Play {
-    val playVersion = "2.8.19"
+    val playVersion = "2.8.20"
+  }
+  object Play_2_9 extends Play {
+    val playVersion = "2.9.0"
+  }
+  object Play_3_0 extends Play {
+    val playVersion = "3.0.0"
   }
-  val play = Seq(Play_2_8, Play_2_7, Play_2_6).map(p => (p.playBinVersion, p)).toMap
+  val play = Seq(Play_3_0, Play_2_9, Play_2_8, Play_2_7, Play_2_6).map(p => (p.playBinVersion, p)).toMap
 
   val acyclic = ivy"com.lihaoyi:::acyclic:0.3.9"
   val ammoniteVersion = "3.0.0-M0-53-084f7f4e"
@@ -352,6 +363,7 @@ trait MillBaseTestsModule extends MillJavaModule with TestModule {
       s"-DTEST_SCALA_3_0_VERSION=${Deps.testScala30Version}",
       s"-DTEST_SCALA_3_1_VERSION=${Deps.testScala31Version}",
       s"-DTEST_SCALA_3_2_VERSION=${Deps.testScala32Version}",
+      s"-DTEST_SCALA_3_3_VERSION=${Deps.testScala33Version}",
       s"-DTEST_SCALAJS_VERSION=${Deps.Scalajs_1.scalaJsVersion}",
       s"-DTEST_SCALANATIVE_VERSION=${Deps.Scalanative_0_4.scalanativeVersion}",
       s"-DTEST_UTEST_VERSION=${Deps.utest.dep.version}",
@@ -739,7 +751,9 @@ object contrib extends Module {
         Seq(
           s"-DTEST_PLAY_VERSION_2_6=${Deps.Play_2_6.playVersion}",
           s"-DTEST_PLAY_VERSION_2_7=${Deps.Play_2_7.playVersion}",
-          s"-DTEST_PLAY_VERSION_2_8=${Deps.Play_2_8.playVersion}"
+          s"-DTEST_PLAY_VERSION_2_8=${Deps.Play_2_8.playVersion}",
+          s"-DTEST_PLAY_VERSION_2_9=${Deps.Play_2_9.playVersion}",
+          s"-DTEST_PLAY_VERSION_3_0=${Deps.Play_3_0.playVersion}"
         )
     }
 
diff --git a/contrib/playlib/api/src/mill/playlib/api/Versions.java b/contrib/playlib/api/src/mill/playlib/api/Versions.java
index cf70aff9e94..9c31b143eba 100644
--- a/contrib/playlib/api/src/mill/playlib/api/Versions.java
+++ b/contrib/playlib/api/src/mill/playlib/api/Versions.java
@@ -4,4 +4,6 @@ public class Versions {
     public static final String PLAY_2_6 = "2.6";
     public static final String PLAY_2_7 = "2.7";
     public static final String PLAY_2_8 = "2.8";
+    public static final String PLAY_2_9 = "2.9";
+    public static final String PLAY_3_0 = "3.0";
 }
diff --git a/contrib/playlib/readme.adoc b/contrib/playlib/readme.adoc
index 166fa3299ca..11275247940 100644
--- a/contrib/playlib/readme.adoc
+++ b/contrib/playlib/readme.adoc
@@ -47,10 +47,9 @@ import mill._
 import $ivy.`com.lihaoyi::mill-contrib-playlib:`,  mill.playlib._
 
 object core extends PlayModule {
-    //config
-    override def scalaVersion= T{"2.13.8"}
-    override def playVersion= T{"2.8.16"}
-    override def twirlVersion= T{"1.5.1"}
+    // config
+    override def scalaVersion = T { "2.13.12" }
+    override def playVersion = T { "2.8.20" }
 
     object test extends PlayTests
 }
@@ -108,18 +107,18 @@ ivy"com.typesafe.play::play-akka-http-server:${playVersion()}"
 === Using `PlayApiModule`
 
 The `PlayApiModule` trait behaves the same as the `PlayModule` trait but it won't process .scala
-.html files and you don't need to define the `twirlVersion:
+.html files:
 
 .`build.sc`
 [source,scala]
 ----
 import mill._
-import $ivy.`com.lihaoyi::mill-contrib-playlib:$MILL_VERSION`,  mill.playlib._
+import $ivy.`com.lihaoyi::mill-contrib-playlib:`,  mill.playlib._
 
 object core extends PlayApiModule {
-    //config
-    override def scalaVersion= T{"2.13.8"}
-    override def playVersion= T{"2.8.16"}
+    // config
+    override def scalaVersion = T { "2.13.12" }
+    override def playVersion = T { "2.8.20" }
 
     object test extends PlayTests
 }
@@ -154,9 +153,9 @@ import mill._
 import $ivy.`com.lihaoyi::mill-contrib-playlib:$MILL_VERSION`, mill.playlib._
 
 object core extends PlayApiModule {
-    //config
-    override def scalaVersion= T{"2.13.8"}
-    override def playVersion= T{"2.8.16"}
+    // config
+    override def scalaVersion = T{ "2.13.12" }
+    override def playVersion = T{ "2.8.20" }
 
     object test extends PlayTests
 
@@ -192,13 +191,12 @@ Looking back at the sample build definition in <<_using_playmodule>>:
 [source,scala]
 ----
 import mill._
-import $ivy.`com.lihaoyi::mill-contrib-playlib:$MILL_VERSION`, mill.playlib._
+import $ivy.`com.lihaoyi::mill-contrib-playlib:`, mill.playlib._
 
 object core extends PlayModule {
-    //config
-    override def scalaVersion= T{"2.13.8"}
-    override def playVersion= T{"2.8.16"}
-    override def twirlVersion= T{"1.5.1"}
+    // config
+    override def scalaVersion = T { "2.13.12" }
+    override def playVersion = T { "2.8.20" }
 
     object test extends PlayTests
 }
@@ -236,10 +234,9 @@ import mill._
 import $ivy.`com.lihaoyi::mill-contrib-playlib:`,  mill.playlib._
 
 object core extends PlayModule with SingleModule {
-	//config
-	override def scalaVersion= T{"2.13.8"}
-	override def playVersion= T{"2.8.16"}
-	override def twirlVersion= T{"1.5.1"}
+	// config
+	override def scalaVersion = T { "2.13.12" }
+	override def playVersion = T { "2.8.20" }
 
 	object test extends PlayTests
 }
@@ -281,8 +278,8 @@ import mill._
 import $ivy.`com.lihaoyi::mill-contrib-playlib:`,  mill.playlib._
 
 object app extends ScalaModule with RouterModule {
-  def playVersion= T{"2.8.16"}
-  def scalaVersion= T{"2.13.8"}
+  def playVersion = T{ "2.8.20" }
+  def scalaVersion = T { "2.13.12" }
 }
 ----
 
@@ -336,7 +333,7 @@ import mill.scalalib._
 import $ivy.`com.lihaoyi::mill-contrib-playlib:$MILL_VERSION`,  mill.playlib._
 
 object app extends ScalaModule with RouterModule {
-  def playVersion = "2.8.16"
+  def playVersion = "2.8.20"
   override def routesAdditionalImport = Seq("my.additional.stuff._", "my.other.stuff._")
 }
 ----
diff --git a/contrib/playlib/src/mill/playlib/PlayModule.scala b/contrib/playlib/src/mill/playlib/PlayModule.scala
index eed15cec625..9984dde87c2 100644
--- a/contrib/playlib/src/mill/playlib/PlayModule.scala
+++ b/contrib/playlib/src/mill/playlib/PlayModule.scala
@@ -12,6 +12,8 @@ trait PlayApiModule extends Dependencies with Router with Server {
         case Versions.PLAY_2_6 => "3.1.3"
         case Versions.PLAY_2_7 => "4.0.3"
         case Versions.PLAY_2_8 => "5.1.0"
+        case Versions.PLAY_2_9 => "6.0.0"
+        case _ => "7.0.0"
       }
       Agg(ivy"org.scalatestplus.play::scalatestplus-play::${scalatestPlusPlayVersion}")
     }
@@ -21,4 +23,14 @@ trait PlayApiModule extends Dependencies with Router with Server {
   def start(args: Task[Args] = T.task(Args())) = T.command { run(args) }
 
 }
-trait PlayModule extends PlayApiModule with Static with Twirl
+trait PlayModule extends PlayApiModule with Static with Twirl {
+  override def twirlVersion = T {
+    playMinorVersion() match {
+      case "2.6" => "1.3.16"
+      case "2.7" => "1.4.2"
+      case "2.8" => "1.5.1"
+      case "2.9" => "1.6.2"
+      case _ => "2.0.1"
+    }
+  }
+}
diff --git a/contrib/playlib/src/mill/playlib/RouterModule.scala b/contrib/playlib/src/mill/playlib/RouterModule.scala
index 3b9ee6cc03c..07a20c05ac1 100644
--- a/contrib/playlib/src/mill/playlib/RouterModule.scala
+++ b/contrib/playlib/src/mill/playlib/RouterModule.scala
@@ -48,7 +48,14 @@ trait RouterModule extends ScalaModule with Version {
   def routerClasspath: T[Agg[PathRef]] = T {
     resolveDeps(T.task {
       val bind = bindDependency()
-      Agg(ivy"com.typesafe.play::routes-compiler:${playVersion()}").map(bind)
+      playMinorVersion() match {
+        case "2.6" | "2.7" | "2.8" =>
+          Agg(ivy"com.typesafe.play::routes-compiler:${playVersion()}").map(bind)
+        case "2.9" =>
+          Agg(ivy"com.typesafe.play::play-routes-compiler:${playVersion()}").map(bind)
+        case _ =>
+          Agg(ivy"org.playframework::play-routes-compiler:${playVersion()}").map(bind)
+      }
     })()
   }
 
diff --git a/contrib/playlib/src/mill/playlib/Version.scala b/contrib/playlib/src/mill/playlib/Version.scala
index f5d7d9d32ee..d70ae9ae726 100644
--- a/contrib/playlib/src/mill/playlib/Version.scala
+++ b/contrib/playlib/src/mill/playlib/Version.scala
@@ -9,10 +9,14 @@ private[playlib] trait Version extends Module {
   def playVersion: T[String]
 
   private[playlib] def playMinorVersion: T[String] = T {
-    playVersion().split("\\.").take(2).mkString(".")
+    playVersion().split('.').take(2).mkString(".")
+  }
+
+  private[playlib] def playOrganization: T[String] = T.task {
+    if (playVersion().startsWith("2.")) "com.typesafe.play" else "org.playframework"
   }
 
   private[playlib] def component(id: String) = T.task {
-    ivy"com.typesafe.play::$id::${playVersion()}"
+    ivy"${playOrganization()}::$id::${playVersion()}"
   }
 }
diff --git a/contrib/playlib/test/resources/hello-world/core/routes/routes b/contrib/playlib/test/resources/hello-world/core/routes/routes
index f71b0cdd826..230c627d528 100644
--- a/contrib/playlib/test/resources/hello-world/core/routes/routes
+++ b/contrib/playlib/test/resources/hello-world/core/routes/routes
@@ -1,3 +1,3 @@
-GET        /                    controllers.HomeController.index
+GET        /                    controllers.HomeController.index()
 GET        /assets/*file        controllers.Assets.versioned(path="/public", file: Asset)
 ->         /sub                 sub.Routes
\ No newline at end of file
diff --git a/contrib/playlib/test/resources/invalid/core/routes/routes b/contrib/playlib/test/resources/invalid/core/routes/routes
index 5c946fc63b4..35ec45f9c84 100644
--- a/contrib/playlib/test/resources/invalid/core/routes/routes
+++ b/contrib/playlib/test/resources/invalid/core/routes/routes
@@ -1,4 +1,4 @@
-GET        /                    controllers.HomeController.index
+GET        /                    controllers.HomeController.index()
 ->         /sub                 sub.Routes
 GET        /assets/*file        controllers.Assets.versioned(path="/public", file: Asset)
 BOB        =error               controllers.HomeController.error(foo)
\ No newline at end of file
diff --git a/contrib/playlib/test/resources/invalidsub/core/routes/routes b/contrib/playlib/test/resources/invalidsub/core/routes/routes
index 5c946fc63b4..35ec45f9c84 100644
--- a/contrib/playlib/test/resources/invalidsub/core/routes/routes
+++ b/contrib/playlib/test/resources/invalidsub/core/routes/routes
@@ -1,4 +1,4 @@
-GET        /                    controllers.HomeController.index
+GET        /                    controllers.HomeController.index()
 ->         /sub                 sub.Routes
 GET        /assets/*file        controllers.Assets.versioned(path="/public", file: Asset)
 BOB        =error               controllers.HomeController.error(foo)
\ No newline at end of file
diff --git a/contrib/playlib/test/resources/playmulti/core/conf/routes b/contrib/playlib/test/resources/playmulti/core/conf/routes
index 2ac6b3366eb..60e8169b9c0 100644
--- a/contrib/playlib/test/resources/playmulti/core/conf/routes
+++ b/contrib/playlib/test/resources/playmulti/core/conf/routes
@@ -4,7 +4,7 @@
 # ~~~~
 
 # An example controller showing a sample home page
-GET     /                           controllers.HomeController.index
+GET     /                           controllers.HomeController.index()
 
 # Map static resources from the /public folder to the /assets URL path
 GET     /assets/*file               controllers.Assets.versioned(path="/public", file: Asset)
diff --git a/contrib/playlib/test/resources/playsingle/conf/routes b/contrib/playlib/test/resources/playsingle/conf/routes
index 2ac6b3366eb..60e8169b9c0 100644
--- a/contrib/playlib/test/resources/playsingle/conf/routes
+++ b/contrib/playlib/test/resources/playsingle/conf/routes
@@ -4,7 +4,7 @@
 # ~~~~
 
 # An example controller showing a sample home page
-GET     /                           controllers.HomeController.index
+GET     /                           controllers.HomeController.index()
 
 # Map static resources from the /public folder to the /assets URL path
 GET     /assets/*file               controllers.Assets.versioned(path="/public", file: Asset)
diff --git a/contrib/playlib/test/resources/playsingleapi/conf/routes b/contrib/playlib/test/resources/playsingleapi/conf/routes
index 2ac6b3366eb..60e8169b9c0 100644
--- a/contrib/playlib/test/resources/playsingleapi/conf/routes
+++ b/contrib/playlib/test/resources/playsingleapi/conf/routes
@@ -4,7 +4,7 @@
 # ~~~~
 
 # An example controller showing a sample home page
-GET     /                           controllers.HomeController.index
+GET     /                           controllers.HomeController.index()
 
 # Map static resources from the /public folder to the /assets URL path
 GET     /assets/*file               controllers.Assets.versioned(path="/public", file: Asset)
diff --git a/contrib/playlib/test/src/mill/playlib/PlayModuleTests.scala b/contrib/playlib/test/src/mill/playlib/PlayModuleTests.scala
index 03e505b9d87..138d6075c10 100644
--- a/contrib/playlib/test/src/mill/playlib/PlayModuleTests.scala
+++ b/contrib/playlib/test/src/mill/playlib/PlayModuleTests.scala
@@ -12,8 +12,6 @@ object PlayModuleTests extends TestSuite with PlayTestSuite {
       val (crossScalaVersion, crossPlayVersion) = (crossValue, crossValue2)
       override def playVersion = crossPlayVersion
       override def scalaVersion = crossScalaVersion
-      override def twirlVersion = "1.5.1"
-      override def twirlScalaVersion = sys.props.getOrElse("MILL_SCALA_2_13_VERSION", ???)
       object test extends PlayTests
       override def ivyDeps = T { super.ivyDeps() ++ Agg(ws()) }
     }
@@ -77,41 +75,46 @@ object PlayModuleTests extends TestSuite with PlayTestSuite {
     }
     test("compile") {
       matrix.foreach { case (scalaVersion, playVersion) =>
-        workspaceTest(playmulti) { eval =>
-          val eitherResult = eval.apply(playmulti.core(scalaVersion, playVersion).compile)
-          val Right((result, evalCount)) = eitherResult
-          val outputFiles = os.walk(result.classes.path).filter(os.isFile)
-          val expectedClassfiles = Seq[os.RelPath](
-            os.RelPath("controllers/HomeController.class"),
-            os.RelPath("controllers/ReverseAssets.class"),
-            os.RelPath("controllers/ReverseHomeController.class"),
-            os.RelPath("controllers/routes.class"),
-            os.RelPath("controllers/routes$javascript.class"),
-            os.RelPath("controllers/javascript/ReverseHomeController.class"),
-            os.RelPath("controllers/javascript/ReverseAssets.class"),
-            os.RelPath("router/Routes$$anonfun$routes$1.class"),
-            os.RelPath("router/Routes.class"),
-            os.RelPath("router/RoutesPrefix$.class"),
-            os.RelPath("router/RoutesPrefix.class"),
-            os.RelPath("views/html/index$.class"),
-            os.RelPath("views/html/index.class"),
-            os.RelPath("views/html/main$.class"),
-            os.RelPath("views/html/main.class")
-          ).map(
-            eval.outPath / "core" / scalaVersion / playVersion / "compile.dest" / "classes" / _
-          )
-          assert(
-            result.classes.path == eval.outPath / "core" / scalaVersion / playVersion / "compile.dest" / "classes",
-            outputFiles.nonEmpty,
-            outputFiles.forall(expectedClassfiles.contains),
-            outputFiles.size == 15,
-            evalCount > 0
-          )
+        skipUnsupportedVersions(playVersion) {
+          workspaceTest(playmulti) { eval =>
+            val eitherResult = eval.apply(playmulti.core(scalaVersion, playVersion).compile)
+            val Right((result, evalCount)) = eitherResult
+            val outputClassFiles =
+              os.walk(result.classes.path).filter(f => os.isFile(f) && f.ext == "class")
 
-          // don't recompile if nothing changed
-          val Right((_, unchangedEvalCount)) =
-            eval.apply(playmulti.core(scalaVersion, playVersion).compile)
-          assert(unchangedEvalCount == 0)
+            val expectedClassfiles = Seq[os.RelPath](
+              os.RelPath("controllers/HomeController.class"),
+              os.RelPath("controllers/ReverseAssets.class"),
+              os.RelPath("controllers/ReverseHomeController.class"),
+              os.RelPath("controllers/routes.class"),
+              os.RelPath("controllers/routes$javascript.class"),
+              os.RelPath("controllers/javascript/ReverseHomeController.class"),
+              os.RelPath("controllers/javascript/ReverseAssets.class"),
+              if (scalaVersion.startsWith("3.")) os.RelPath("router/Routes$$anon$1.class")
+              else os.RelPath("router/Routes$$anonfun$routes$1.class"),
+              os.RelPath("router/Routes.class"),
+              os.RelPath("router/RoutesPrefix$.class"),
+              os.RelPath("router/RoutesPrefix.class"),
+              os.RelPath("views/html/index$.class"),
+              os.RelPath("views/html/index.class"),
+              os.RelPath("views/html/main$.class"),
+              os.RelPath("views/html/main.class")
+            ).map(
+              eval.outPath / "core" / scalaVersion / playVersion / "compile.dest" / "classes" / _
+            )
+            assert(
+              result.classes.path == eval.outPath / "core" / scalaVersion / playVersion / "compile.dest" / "classes",
+              outputClassFiles.nonEmpty,
+              outputClassFiles.forall(expectedClassfiles.contains),
+              outputClassFiles.size == 15,
+              evalCount > 0
+            )
+
+            // don't recompile if nothing changed
+            val Right((_, unchangedEvalCount)) =
+              eval.apply(playmulti.core(scalaVersion, playVersion).compile)
+            assert(unchangedEvalCount == 0)
+          }
         }
       }
     }
diff --git a/contrib/playlib/test/src/mill/playlib/PlaySingleApiModuleTests.scala b/contrib/playlib/test/src/mill/playlib/PlaySingleApiModuleTests.scala
index 865c550984d..a76becc7837 100644
--- a/contrib/playlib/test/src/mill/playlib/PlaySingleApiModuleTests.scala
+++ b/contrib/playlib/test/src/mill/playlib/PlaySingleApiModuleTests.scala
@@ -8,8 +8,7 @@ object PlaySingleApiModuleTests extends TestSuite with PlayTestSuite {
 
   object playsingleapi extends TestUtil.BaseModule with PlayApiModule with SingleModule {
     override def playVersion = T { testPlay28 }
-    def twirlVersion = T { "1.5.1" }
-    override def scalaVersion = T { "2.13.8" }
+    override def scalaVersion = T { "2.13.12" }
     object test extends PlayTests
   }
 
diff --git a/contrib/playlib/test/src/mill/playlib/PlaySingleModuleTests.scala b/contrib/playlib/test/src/mill/playlib/PlaySingleModuleTests.scala
index 8dc34e44ce7..5a413b6f896 100644
--- a/contrib/playlib/test/src/mill/playlib/PlaySingleModuleTests.scala
+++ b/contrib/playlib/test/src/mill/playlib/PlaySingleModuleTests.scala
@@ -8,10 +8,7 @@ object PlaySingleModuleTests extends TestSuite with PlayTestSuite {
 
   object playsingle extends TestUtil.BaseModule with PlayModule with SingleModule {
     override def playVersion = T { testPlay28 }
-    override def twirlVersion = T { "1.5.1" }
-    override def twirlScalaVersion: T[String] =
-      T { sys.props.getOrElse("MILL_SCALA_2_13_VERSION", ???) }
-    override def scalaVersion = T { sys.props.getOrElse("MILL_SCALA_2_13_VERSION", ???) }
+    override def scalaVersion = T { sys.props.getOrElse("TEST_SCALA_2_13_VERSION", ???) }
     object test extends PlayTests
   }
 
diff --git a/contrib/playlib/test/src/mill/playlib/PlayTestSuite.scala b/contrib/playlib/test/src/mill/playlib/PlayTestSuite.scala
index 450208746be..05ac0048cbc 100644
--- a/contrib/playlib/test/src/mill/playlib/PlayTestSuite.scala
+++ b/contrib/playlib/test/src/mill/playlib/PlayTestSuite.scala
@@ -5,20 +5,33 @@ import utest.framework.TestPath
 
 trait PlayTestSuite {
 
-  val testScala212 = sys.props.getOrElse("MILL_SCALA_2_12_VERSION", ???)
-  val testScala213 = sys.props.getOrElse("MILL_SCALA_2_13_VERSION", ???)
+  val testScala212 = sys.props.getOrElse("TEST_SCALA_2_12_VERSION", ???)
+  val testScala213 = sys.props.getOrElse("TEST_SCALA_2_13_VERSION", ???)
+  val testScala3 = sys.props.getOrElse("TEST_SCALA_3_3_VERSION", ???)
 
   val testPlay26 = sys.props.getOrElse("TEST_PLAY_VERSION_2_6", ???)
   val testPlay27 = sys.props.getOrElse("TEST_PLAY_VERSION_2_7", ???)
   val testPlay28 = sys.props.getOrElse("TEST_PLAY_VERSION_2_8", ???)
+  val testPlay29 = sys.props.getOrElse("TEST_PLAY_VERSION_2_9", ???)
+  val testPlay30 = sys.props.getOrElse("TEST_PLAY_VERSION_3_0", ???)
 
   val matrix = Seq(
     (testScala212, testPlay26),
     (testScala212, testPlay27),
     (testScala213, testPlay27),
-    (testScala213, testPlay28)
+    (testScala213, testPlay28),
+    (testScala213, testPlay29),
+    (testScala3, testPlay29),
+    (testScala213, testPlay30),
+    (testScala3, testPlay30)
   )
 
+  def skipUnsupportedVersions(playVersion: String)(test: => Unit) = playVersion match {
+    case s"2.$minor.$_" if minor.toIntOption.exists(_ < 9) => test
+    case _ if scala.util.Properties.isJavaAtLeast(11) => test
+    case _ => System.err.println(s"Skipping since play $playVersion doesn't support Java 8")
+  }
+
   def resourcePath: os.Path
 
   def workspaceTest[T, M <: TestUtil.BaseModule](
diff --git a/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala b/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala
index 12687c6c19c..84b543c570a 100644
--- a/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala
+++ b/contrib/playlib/test/src/mill/playlib/RouterModuleTests.scala
@@ -34,85 +34,91 @@ object RouterModuleTests extends TestSuite with PlayTestSuite {
   def tests: Tests = Tests {
     test("compileRouter") {
       matrix.foreach { case (scalaVersion, playVersion) =>
-        workspaceTest(HelloWorld) { eval =>
-          val eitherResult = eval.apply(HelloWorld.core(scalaVersion, playVersion).compileRouter)
-          val Right((result, evalCount)) = eitherResult
-          val outputFiles = os.walk(result.classes.path).filter(os.isFile)
-          val expectedClassfiles = Seq[os.RelPath](
-            os.RelPath("controllers/ReverseRoutes.scala"),
-            os.RelPath("controllers/routes.java"),
-            os.RelPath("router/Routes.scala"),
-            os.RelPath("router/RoutesPrefix.scala"),
-            os.RelPath("sub/Routes.scala"),
-            os.RelPath("sub/RoutesPrefix.scala"),
-            os.RelPath("controllers/javascript/JavaScriptReverseRoutes.scala")
-          ).map(
-            eval.outPath / "core" / scalaVersion / playVersion / "compileRouter.dest" / _
-          )
-          assert(
-            result.classes.path == eval.outPath / "core" / scalaVersion / playVersion / "compileRouter.dest",
-            outputFiles.nonEmpty,
-            outputFiles.forall(expectedClassfiles.contains),
-            outputFiles.size == 7,
-            evalCount > 0
-          )
+        skipUnsupportedVersions(playVersion) {
+          workspaceTest(HelloWorld) { eval =>
+            val eitherResult = eval.apply(HelloWorld.core(scalaVersion, playVersion).compileRouter)
+            val Right((result, evalCount)) = eitherResult
+            val outputFiles = os.walk(result.classes.path).filter(os.isFile)
+            val expectedClassfiles = Seq[os.RelPath](
+              os.RelPath("controllers/ReverseRoutes.scala"),
+              os.RelPath("controllers/routes.java"),
+              os.RelPath("router/Routes.scala"),
+              os.RelPath("router/RoutesPrefix.scala"),
+              os.RelPath("sub/Routes.scala"),
+              os.RelPath("sub/RoutesPrefix.scala"),
+              os.RelPath("controllers/javascript/JavaScriptReverseRoutes.scala")
+            ).map(
+              eval.outPath / "core" / scalaVersion / playVersion / "compileRouter.dest" / _
+            )
+            assert(
+              result.classes.path == eval.outPath / "core" / scalaVersion / playVersion / "compileRouter.dest",
+              outputFiles.nonEmpty,
+              outputFiles.forall(expectedClassfiles.contains),
+              outputFiles.size == 7,
+              evalCount > 0
+            )
 
-          // don't recompile if nothing changed
-          val Right((_, unchangedEvalCount)) =
-            eval.apply(HelloWorld.core(scalaVersion, playVersion).compileRouter)
+            // don't recompile if nothing changed
+            val Right((_, unchangedEvalCount)) =
+              eval.apply(HelloWorld.core(scalaVersion, playVersion).compileRouter)
 
-          assert(unchangedEvalCount == 0)
+            assert(unchangedEvalCount == 0)
+          }
         }
       }
     }
     test("compileRouterInvalidRoutes") {
       matrix.foreach { case (scalaVersion, playVersion) =>
-        workspaceTest(HelloWorld, resourcePath = invalidResourcePath) { eval =>
-          val project = HelloWorld.core(scalaVersion, playVersion)
-          val eitherResult = eval.apply(project.compileRouter)
-          val Left(Failure(message, x)) = eitherResult
-          val playExpectedMessage =
-            if (playVersion.startsWith("2.6.")) {
-              "HTTP Verb (GET, POST, ...), include (->), comment (#), or modifier line (+) expected"
-            } else {
-              "end of input expected"
-            }
-          val expectedMessage = "Unable to compile play routes, compilation error in " +
-            project.millSourcePath.toIO.getAbsolutePath.replace(
-              """\""",
-              "/"
-            ) + "/routes/routes at line 4, " +
-            "column" + " 1: " + playExpectedMessage
-          // fix windows paths
-          val normalizeMessage = message.replace("""\""", "/")
-          assert(
-            normalizeMessage == expectedMessage
-          )
+        skipUnsupportedVersions(playVersion) {
+          workspaceTest(HelloWorld, resourcePath = invalidResourcePath) { eval =>
+            val project = HelloWorld.core(scalaVersion, playVersion)
+            val eitherResult = eval.apply(project.compileRouter)
+            val Left(Failure(message, x)) = eitherResult
+            val playExpectedMessage =
+              if (playVersion.startsWith("2.6.")) {
+                "HTTP Verb (GET, POST, ...), include (->), comment (#), or modifier line (+) expected"
+              } else {
+                "end of input expected"
+              }
+            val expectedMessage = "Unable to compile play routes, compilation error in " +
+              project.millSourcePath.toIO.getAbsolutePath.replace(
+                """\""",
+                "/"
+              ) + "/routes/routes at line 4, " +
+              "column" + " 1: " + playExpectedMessage
+            // fix windows paths
+            val normalizeMessage = message.replace("""\""", "/")
+            assert(
+              normalizeMessage == expectedMessage
+            )
+          }
         }
       }
     }
     test("compileRouterInvalidSubRoutes") {
       matrix.foreach { case (scalaVersion, playVersion) =>
-        workspaceTest(HelloWorld, resourcePath = invalidSubResourcePath) { eval =>
-          val eitherResult = eval.apply(HelloWorld.core(scalaVersion, playVersion).compileRouter)
-          val Left(Failure(message, x)) = eitherResult
-          val playExpectedMessage =
-            if (playVersion.startsWith("2.6.")) {
-              "HTTP Verb (GET, POST, ...), include (->), comment (#), or modifier line (+) expected"
-            } else {
-              "end of input expected"
-            }
-          val expectedMessage = "Unable to compile play routes, compilation error in " +
-            HelloWorld.core.millSourcePath.toIO.getAbsolutePath.replace(
-              """\""",
-              "/"
-            ) + "/routes/sub.routes at line 3, column" +
-            " 1: " + playExpectedMessage
-          // fix windows paths
-          val normalizeMessage = message.replace("""\""", "/")
-          assert(
-            normalizeMessage == expectedMessage
-          )
+        skipUnsupportedVersions(playVersion) {
+          workspaceTest(HelloWorld, resourcePath = invalidSubResourcePath) { eval =>
+            val eitherResult = eval.apply(HelloWorld.core(scalaVersion, playVersion).compileRouter)
+            val Left(Failure(message, x)) = eitherResult
+            val playExpectedMessage =
+              if (playVersion.startsWith("2.6.")) {
+                "HTTP Verb (GET, POST, ...), include (->), comment (#), or modifier line (+) expected"
+              } else {
+                "end of input expected"
+              }
+            val expectedMessage = "Unable to compile play routes, compilation error in " +
+              HelloWorld.core.millSourcePath.toIO.getAbsolutePath.replace(
+                """\""",
+                "/"
+              ) + "/routes/sub.routes at line 3, column" +
+              " 1: " + playExpectedMessage
+            // fix windows paths
+            val normalizeMessage = message.replace("""\""", "/")
+            assert(
+              normalizeMessage == expectedMessage
+            )
+          }
         }
       }
     }
diff --git a/contrib/playlib/worker/2.9/src/mill/playlib/worker/RouteCompilerWorker.scala b/contrib/playlib/worker/2.9/src/mill/playlib/worker/RouteCompilerWorker.scala
new file mode 100644
index 00000000000..e24557b2651
--- /dev/null
+++ b/contrib/playlib/worker/2.9/src/mill/playlib/worker/RouteCompilerWorker.scala
@@ -0,0 +1,3 @@
+package mill.playlib.worker
+
+private[playlib] class RouteCompilerWorker extends RouteCompilerWorkerBase
diff --git a/contrib/playlib/worker/3.0/src/mill/playlib/worker/RouteCompilerWorker.scala b/contrib/playlib/worker/3.0/src/mill/playlib/worker/RouteCompilerWorker.scala
new file mode 100644
index 00000000000..e24557b2651
--- /dev/null
+++ b/contrib/playlib/worker/3.0/src/mill/playlib/worker/RouteCompilerWorker.scala
@@ -0,0 +1,3 @@
+package mill.playlib.worker
+
+private[playlib] class RouteCompilerWorker extends RouteCompilerWorkerBase
diff --git a/contrib/twirllib/src/mill/twirllib/TwirlModule.scala b/contrib/twirllib/src/mill/twirllib/TwirlModule.scala
index 7bd6a46e364..c00a3904dda 100644
--- a/contrib/twirllib/src/mill/twirllib/TwirlModule.scala
+++ b/contrib/twirllib/src/mill/twirllib/TwirlModule.scala
@@ -5,6 +5,7 @@ import coursier.{Dependency, Repository}
 import mill.api.PathRef
 import mill.scalalib._
 import mill.api.Loose
+import mill.main.BuildInfo
 
 import scala.io.Codec
 import scala.util.Properties
@@ -17,7 +18,12 @@ trait TwirlModule extends mill.Module { twirlModule =>
    * The Scala version matching the twirl version.
    * @since Mill after 0.10.5
    */
-  def twirlScalaVersion: T[String]
+  def twirlScalaVersion: T[String] = T {
+    twirlVersion() match {
+      case s"1.$minor.$_" if minor.toIntOption.exists(_ < 4) => BuildInfo.workerScalaVersion212
+      case _ => BuildInfo.scalaVersion
+    }
+  }
 
   def twirlSources: T[Seq[PathRef]] = T.sources {
     millSourcePath / "views"
@@ -25,11 +31,11 @@ trait TwirlModule extends mill.Module { twirlModule =>
 
   /**
    * Replicate the logic from twirl build,
-   *      see: https://github.com/playframework/twirl/blob/bdac9bb9470a7533a44b40c37fb3064737418768/build.sbt#L17-L22
+   *      see: https://github.com/playframework/twirl/blob/2.0.1/build.sbt#L12-L17
    */
   private def scalaParserCombinatorsVersion: T[String] = twirlScalaVersion.map {
     case v if v.startsWith("2.") => "1.1.2"
-    case _ => "2.1.0"
+    case _ => "2.3.0"
   }
 
   /**
@@ -37,9 +43,13 @@ trait TwirlModule extends mill.Module { twirlModule =>
    */
   def twirlIvyDeps: T[Agg[Dep]] = T {
     Agg(
-      ivy"com.typesafe.play::twirl-compiler:${twirlVersion()}",
-      ivy"org.scala-lang.modules::scala-parser-combinators:${scalaParserCombinatorsVersion()}"
-    )
+      if (twirlVersion().startsWith("1."))
+        ivy"com.typesafe.play::twirl-compiler:${twirlVersion()}"
+      else ivy"org.playframework.twirl::twirl-compiler:${twirlVersion()}"
+    ) ++
+      Agg(
+        ivy"org.scala-lang.modules::scala-parser-combinators:${scalaParserCombinatorsVersion()}"
+      )
   }
 
   /**
diff --git a/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala b/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala
index a5f2b75236e..6bae2e57e54 100644
--- a/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala
+++ b/contrib/twirllib/test/src/mill/twirllib/HelloWorldTests.scala
@@ -6,7 +6,6 @@ import utest.{TestSuite, Tests, assert, _}
 
 trait HelloWorldTests extends TestSuite {
   val testTwirlVersion: String
-  val testTwirlScalaVersion: String
 
   trait HelloBase extends TestUtil.BaseModule {
     override def millSourcePath: os.Path =
@@ -15,7 +14,6 @@ trait HelloWorldTests extends TestSuite {
 
   trait HelloWorldModule extends mill.twirllib.TwirlModule {
     def twirlVersion = testTwirlVersion
-    val twirlScalaVersion = testTwirlScalaVersion
   }
 
   object HelloWorld extends HelloBase {
@@ -78,6 +76,12 @@ trait HelloWorldTests extends TestSuite {
     "@something.else.Thing()"
   )
 
+  def skipUnsupportedVersions(test: => Unit) = testTwirlVersion match {
+    case s"1.$minor.$_" if minor.toIntOption.exists(_ < 6) => test
+    case _ if scala.util.Properties.isJavaAtLeast(11) => test
+    case _ => System.err.println(s"Skipping since twirl $testTwirlVersion doesn't support Java 8")
+  }
+
   def tests: Tests = Tests {
     "twirlVersion" - {
 
@@ -91,83 +95,95 @@ trait HelloWorldTests extends TestSuite {
         )
       }
     }
-    "compileTwirl" - workspaceTest(HelloWorld, "hello-world", debug = true) { eval =>
-      val res = eval.apply(HelloWorld.core.compileTwirl)
-      assert(res.isRight)
-      val Right((result, evalCount)) = res
-
-      val outputFiles = os.walk(result.classes.path).filter(_.last.endsWith(".scala"))
-      val expectedClassfiles = compileClassfiles.map(
-        eval.outPath / "core" / "compileTwirl.dest" / _
-      )
-
-      assert(
-        result.classes.path == eval.outPath / "core" / "compileTwirl.dest",
-        outputFiles.nonEmpty,
-        outputFiles.forall(expectedClassfiles.contains),
-        outputFiles.size == 3,
-        evalCount > 0,
-        outputFiles.forall { p =>
-          val lines = os.read.lines(p).map(_.trim)
-          (expectedDefaultImports ++ testAdditionalImports.map(s => s"import $s")).forall(
-            lines.contains
+    test("compileTwirl") {
+      skipUnsupportedVersions {
+        workspaceTest(HelloWorld, "hello-world", debug = true) { eval =>
+          val res = eval.apply(HelloWorld.core.compileTwirl)
+          assert(res.isRight)
+          val Right((result, evalCount)) = res
+
+          val outputFiles = os.walk(result.classes.path).filter(_.last.endsWith(".scala"))
+          val expectedClassfiles = compileClassfiles.map(
+            eval.outPath / "core" / "compileTwirl.dest" / _
+          )
+
+          assert(
+            result.classes.path == eval.outPath / "core" / "compileTwirl.dest",
+            outputFiles.nonEmpty,
+            outputFiles.forall(expectedClassfiles.contains),
+            outputFiles.size == 3,
+            evalCount > 0,
+            outputFiles.forall { p =>
+              val lines = os.read.lines(p).map(_.trim)
+              (expectedDefaultImports ++ testAdditionalImports.map(s => s"import $s")).forall(
+                lines.contains
+              )
+            },
+            outputFiles.filter(_.toString().contains("hello.template.scala")).forall { p =>
+              val lines = os.read.lines(p).map(_.trim)
+              val expectedClassDeclaration = s"class hello ${testConstructorAnnotations.mkString}"
+              lines.exists(_.startsWith(expectedClassDeclaration))
+            }
           )
-        },
-        outputFiles.filter(_.toString().contains("hello.template.scala")).forall { p =>
-          val lines = os.read.lines(p).map(_.trim)
-          val expectedClassDeclaration = s"class hello ${testConstructorAnnotations.mkString}"
-          lines.exists(_.startsWith(expectedClassDeclaration))
-        }
-      )
 
-      // don't recompile if nothing changed
-      val Right((_, unchangedEvalCount)) =
-        eval.apply(HelloWorld.core.compileTwirl)
+          // don't recompile if nothing changed
+          val Right((_, unchangedEvalCount)) =
+            eval.apply(HelloWorld.core.compileTwirl)
 
-      assert(unchangedEvalCount == 0)
-    }
-    "compileTwirlInclusiveDot" - workspaceTest(
-      HelloWorldWithInclusiveDot,
-      "hello-world-inclusive-dot"
-    ) { eval =>
-      val Right((result, evalCount)) = eval.apply(HelloWorldWithInclusiveDot.core.compileTwirl)
-
-      val outputFiles = os.walk(result.classes.path).filter(_.last.endsWith(".scala"))
-      val expectedClassfiles = compileClassfiles.map(name =>
-        eval.outPath / "core" / "compileTwirl.dest" / name / os.RelPath.up / name.last.replace(
-          ".template.scala",
-          "$$TwirlInclusiveDot.template.scala"
-        )
-      )
-
-      println(s"outputFiles: $outputFiles")
-
-      assert(
-        result.classes.path == eval.outPath / "core" / "compileTwirl.dest",
-        outputFiles.nonEmpty,
-        outputFiles.forall(expectedClassfiles.contains),
-        outputFiles.size == 3,
-        evalCount > 0,
-        outputFiles.filter(_.toString().contains("hello.template.scala")).forall { p =>
-          val lines = os.read.lines(p).map(_.trim)
-          lines.exists(_.contains("$$TwirlInclusiveDot"))
+          assert(unchangedEvalCount == 0)
         }
-      )
+      }
+    }
+    test("compileTwirlInclusiveDot") {
+      skipUnsupportedVersions {
+        workspaceTest(
+          HelloWorldWithInclusiveDot,
+          "hello-world-inclusive-dot"
+        ) { eval =>
+          val Right((result, evalCount)) = eval.apply(HelloWorldWithInclusiveDot.core.compileTwirl)
+
+          val outputFiles = os.walk(result.classes.path).filter(_.last.endsWith(".scala"))
+          val expectedClassfiles = compileClassfiles.map(name =>
+            eval.outPath / "core" / "compileTwirl.dest" / name / os.RelPath.up / name.last.replace(
+              ".template.scala",
+              "$$TwirlInclusiveDot.template.scala"
+            )
+          )
+
+          println(s"outputFiles: $outputFiles")
+
+          assert(
+            result.classes.path == eval.outPath / "core" / "compileTwirl.dest",
+            outputFiles.nonEmpty,
+            outputFiles.forall(expectedClassfiles.contains),
+            outputFiles.size == 3,
+            evalCount > 0,
+            outputFiles.filter(_.toString().contains("hello.template.scala")).forall { p =>
+              val lines = os.read.lines(p).map(_.trim)
+              lines.exists(_.contains("$$TwirlInclusiveDot"))
+            }
+          )
 
-      // don't recompile if nothing changed
-      val Right((_, unchangedEvalCount)) =
-        eval.apply(HelloWorld.core.compileTwirl)
+          // don't recompile if nothing changed
+          val Right((_, unchangedEvalCount)) =
+            eval.apply(HelloWorld.core.compileTwirl)
 
-      assert(unchangedEvalCount == 0)
+          assert(unchangedEvalCount == 0)
+        }
+      }
     }
   }
 }
 
-object HelloWorldTests2_12 extends HelloWorldTests {
-  override val testTwirlVersion = "1.3.15"
-  override val testTwirlScalaVersion = sys.props.getOrElse("MILL_SCALA_2_12_VERSION", ???)
+object HelloWorldTests1_3 extends HelloWorldTests {
+  override val testTwirlVersion = "1.3.16"
+}
+object HelloWorldTests1_5 extends HelloWorldTests {
+  override val testTwirlVersion = "1.5.2"
+}
+object HelloWorldTests1_6 extends HelloWorldTests {
+  override val testTwirlVersion = "1.6.2"
 }
-object HelloWorldTests2_13 extends HelloWorldTests {
-  override val testTwirlVersion = "1.5.1"
-  override val testTwirlScalaVersion = sys.props.getOrElse("MILL_SCALA_2_13_VERSION", ???)
+object HelloWorldTests2_0 extends HelloWorldTests {
+  override val testTwirlVersion = "2.0.1"
 }