Add build support for sbt 2, scala 3.

Author: BillyAutrey

.github/workflows/build-test.yml

@@ -20,7 +20,7 @@ jobs:
       java: 17, 11, 8
       scala: 2.12.20
       cmd: |
-        sbt ++$MATRIX_SCALA test ^scripted
+        sbt ++$MATRIX_SCALA test scripted
 
   finish:
     name: Finish

.github/workflows/format.yml

@@ -18,6 +18,6 @@ jobs:
           persist-credentials: false
 
       - name: Check project is formatted
-        uses: jrouly/scalafmt-native-action@v3
+        uses: jrouly/scalafmt-native-action@v4
         with:
           arguments: '--list --mode diff-ref=origin/main'

.scalafmt.conf

@@ -24,3 +24,8 @@ align.tokens."+" = [
     ]
   }
 ]
+fileOverride {
+  "glob:**/scala-3/**" {
+    runner.dialect = scala3
+  }
+}

build.sbt

@@ -11,6 +11,10 @@ developers += Developer(
   url("https://github.com/playframework")
 )
 
+lazy val scala212 = "2.12.20"
+lazy val scala3 = "3.3.4"
+ThisBuild / crossScalaVersions := Seq(scala212)
+
 libraryDependencies ++= Seq(
   "org.webjars" % "webjars-locator-core" % "0.59",
   "org.specs2" %% "specs2-core"          % "4.20.8" % "test",
@@ -26,3 +30,17 @@ Global / onLoad := (Global / onLoad).value.andThen { s =>
   dynverAssertTagVersion.value
   s
 }
+
+(pluginCrossBuild / sbtVersion) := {
+  scalaBinaryVersion.value match {
+    case "2.12" => "1.10.2"
+    case _      => "2.0.0-M2"
+  }
+}
+
+scalacOptions := {
+  CrossVersion.partialVersion(scalaVersion.value) match {
+    case Some((2, major)) => Seq("-Xsource:3")
+    case _                => Seq.empty
+  }
+}