add sbt 2 cross build

.github/workflows/build-test.yml

@@ -31,6 +31,7 @@ jobs:
         }
       cmd: >-
         sbt "
+          + Test/compile;
           set scriptedSbt := \"$MATRIX_SBT\";
           set scriptedLaunchOpts += \"-Dscala.version=$MATRIX_SCALA\";
           show scriptedSbt;

.scalafmt.conf

@@ -57,3 +57,5 @@ rewrite {
   }
   trailingCommas.style = keep # https://scalameta.org/scalafmt/docs/configuration.html#trailing-commas
 }
+
+project.layout = StandardConvention

build.sbt

@@ -50,12 +50,32 @@ Global / onLoad := (Global / onLoad).value.andThen { s =>
   s
 }
 
+crossScalaVersions += "3.7.3"
+
+scalacOptions --= {
+  scalaBinaryVersion.value match {
+    case "3" =>
+      Seq("-Xfatal-warnings")
+    case _ =>
+      Nil
+  }
+}
+
+pluginCrossBuild / sbtVersion := {
+  scalaBinaryVersion.value match {
+    case "2.12" =>
+      sbtVersion.value
+    case _ =>
+      "2.0.0-RC5"
+  }
+}
+
 addCommandAlias(
   "validateCode",
   List(
     "scalafmtSbtCheck",
-    "scalafmtCheckAll",
-    "javafmtCheckAll",
-    "headerCheck"
+    "+ scalafmtCheckAll",
+    "+ javafmtCheckAll",
+    "+ headerCheckAll"
   ).mkString(";")
 )

src/main/scala-2/com/github/sbt/maven/SbtMavenPluginCompat.scala

@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) from 2023 The sbt contributors <https://github.com/sbt>
+ */
+
+package com.github.sbt.maven
+
+import java.io.File
+
+import sbt.Classpaths
+import sbt.Configuration
+import sbt.Keys.Classpath
+import sbt.UpdateReport
+
+private[maven] object SbtMavenPluginCompat {
+  def managedJars(
+      config: Configuration,
+      jarTypes: Set[String],
+      up: UpdateReport
+  ): Seq[File] =
+    Classpaths.managedJars(config, jarTypes, up).map(_.data)
+}

src/main/scala-3/com/github/sbt/maven/SbtMavenPluginCompat.scala

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) from 2023 The sbt contributors <https://github.com/sbt>
+ */
+
+package com.github.sbt.maven
+
+import java.io.File
+
+import sbt.Classpaths
+import sbt.Configuration
+import sbt.Keys.fileConverter
+import sbt.Keys.Classpath
+import sbt.UpdateReport
+
+private[maven] object SbtMavenPluginCompat {
+  inline def managedJars(
+      config: Configuration,
+      jarTypes: Set[String],
+      up: UpdateReport
+  ): Seq[File] = {
+    val converter = fileConverter.value
+    Classpaths.managedJars(config, jarTypes, up, converter).map(x => converter.toPath(x.data).toFile)
+  }
+}

src/main/scala/com/github/sbt/maven/SbtMavenPlugin.scala

@@ -40,7 +40,8 @@ object SbtMavenPlugin extends AutoPlugin {
     val mavenVersion            = settingKey[String]("Maven version")
     val mavenPluginToolsVersion = settingKey[String]("Maven Plugin Tools version")
 
-    val MavenConf       = Configurations.config("scripted-maven").hide
+    val MavenConf = Configurations.config("scripted-maven").hide
+    @transient
     val mavenClasspath  = taskKey[PathFinder]("")
     val mavenLaunchOpts =
       settingKey[Seq[String]]("options to pass to jvm launching Maven tasks")
@@ -66,7 +67,7 @@ object SbtMavenPlugin extends AutoPlugin {
   private def scriptedMavenSettings: Seq[Setting[?]] = Seq(
     ivyConfigurations += MavenConf,
     mavenClasspath := Def.task {
-      PathFinder(Classpaths.managedJars(MavenConf, classpathTypes.value, Keys.update.value).map(_.data))
+      PathFinder(SbtMavenPluginCompat.managedJars(MavenConf, classpathTypes.value, Keys.update.value))
     }.value,
     scripted / sourceDirectory := sourceDirectory.value / "maven-test",
     scripted                   := scriptedTask.evaluated,