From 88569af1e22f9d6ada13eb0849c5276cd755fdc8 Mon Sep 17 00:00:00 2001
From: Matthias Kurz <m.kurz@irregular.at>
Date: Tue, 15 Sep 2026 09:00:58 +0200
Subject: [PATCH] Build Scala 3 artifacts with 3.3 and test newer versions

Use Scala 3.3 as the canonical publishing baseline and compile its artifacts with -Yfuture-lazy-vals.

Keep Scala 3.9 LTS and Scala Next as additional compile and test targets in CI. Resolve symbolic Scala version selectors in the build so exact versions remain centralized.
---
 .github/workflows/build-test.yml |  5 +++--
 project/Common.scala             | 11 +++++++++--
 project/Dependencies.scala       | 20 ++++++++++++++++----
 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/build-test.yml b/.github/workflows/build-test.yml
index 2f4cebb..3b5f98f 100644
--- a/.github/workflows/build-test.yml
+++ b/.github/workflows/build-test.yml
@@ -38,8 +38,9 @@ jobs:
     uses: playframework/.github/.github/workflows/cmd.yml@v4
     with:
       java: 21, 17
-      scala: 2.12.x, 2.13.x, 3.x
-      cmd: sbt "++$MATRIX_SCALA ; test"
+      # Symbolic lanes resolve to exact versions in project/Dependencies.scala.
+      scala: 2.12.x, 2.13.x, 3.3.x, 3.9.x, 3.next
+      cmd: sbt -Dscala.version=$MATRIX_SCALA testFull
 
   finish:
     name: Finish
diff --git a/project/Common.scala b/project/Common.scala
index 87b4485..4f49f5a 100644
--- a/project/Common.scala
+++ b/project/Common.scala
@@ -39,8 +39,8 @@ object Common extends AutoPlugin {
       organizationHomepage := Some(uri("https://playframework.com/")),
       homepage             := Some(uri(s"https://github.com/playframework/${repoName}")),
       licenses             := Seq(License("Apache-2.0", uri("https://www.apache.org/licenses/LICENSE-2.0.html"))),
-      scalaVersion         := Scala212,
-      crossScalaVersions   := ScalaVersions,
+      scalaVersion         := resolveScalaVersion(sys.props.getOrElse("scala.version", scala213Version)),
+      crossScalaVersions   := publishedScalaVersions,
       scalacOptions ++= scalacParameters,
       javacOptions ++= javacParameters,
       developers += Developer(
@@ -52,4 +52,11 @@ object Common extends AutoPlugin {
       description := "Cachecontrol - Minimal HTTP cache management library in Scala"
     )
 
+  override def projectSettings =
+    Seq(
+      scalacOptions ++= {
+        if (scalaVersion.value.startsWith("3.3.")) Seq("-Yfuture-lazy-vals") else Seq.empty
+      }
+    )
+
 }
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 8e09d86..ddac6c0 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -4,11 +4,23 @@
 import sbt._
 
 object Dependencies {
-  val Scala212 = "2.12.21"
-  val Scala213 = "2.13.18"
-  val Scala3   = "3.3.8"
+  val scala212Version   = "2.12.21"
+  val scala213Version   = "2.13.18"
+  val scala33LTSVersion = "3.3.8"
+  val scala39LTSVersion = "3.9.0"
+  val scala3NextVersion = "3.10.0-RC2"
 
-  val ScalaVersions = Seq(Scala212, Scala213, Scala3)
+  val publishedScalaVersions = Seq(scala212Version, scala213Version, scala33LTSVersion)
+
+  private val scalaVersionAliases = Map(
+    "2.12.x" -> scala212Version,
+    "2.13.x" -> scala213Version,
+    "3.3.x"  -> scala33LTSVersion,
+    "3.9.x"  -> scala39LTSVersion,
+    "3.next" -> scala3NextVersion,
+  )
+
+  def resolveScalaVersion(version: String): String = scalaVersionAliases.getOrElse(version, version)
 
   def scalaTest = "org.scalatest" %% "scalatest" % "3.2.20" % Test