Add --as-jar option

Putting the project byte code in the class path as a JAR, in the
compile / run / test / repl commands

modules/cli/src/main/scala/scala/cli/commands/compile/Compile.scala

@@ -15,6 +15,7 @@ import scala.cli.commands.update.Update
 import scala.cli.commands.util.BuildCommandHelpers
 import scala.cli.commands.{CommandUtils, ScalaCommand, SpecificationLevel, WatchUtil}
 import scala.cli.config.{ConfigDb, Keys}
+import scala.cli.packaging.Library.fullClassPathMaybeAsJar
 import scala.cli.util.ArgHelpers.*
 import scala.cli.util.ConfigDbUtils
 object Compile extends ScalaCommand[CompileOptions] with BuildCommandHelpers {
@@ -82,7 +83,9 @@ object Compile extends ScalaCommand[CompileOptions] with BuildCommandHelpers {
           } yield s
         if (options.printClassPath)
           for (s <- successulBuildOpt) {
-            val cp = s.fullClassPath.map(_.toString).mkString(File.pathSeparator)
+            val cp = s.fullClassPathMaybeAsJar(options.shared.asJar)
+              .map(_.toString)
+              .mkString(File.pathSeparator)
             println(cp)
           }
         successulBuildOpt.foreach(_.copyOutput(options.shared))

modules/cli/src/main/scala/scala/cli/commands/repl/Repl.scala

@@ -7,6 +7,8 @@ import coursier.cache.FileCache
 import coursier.error.{FetchError, ResolutionError}
 import dependency.*
 
+import java.util.zip.ZipFile
+
 import scala.build.EitherCps.{either, value}
 import scala.build.*
 import scala.build.errors.{BuildException, CantDownloadAmmoniteError, FetchingDependenciesError}
@@ -24,8 +26,10 @@ import scala.cli.commands.run.RunMode
 import scala.cli.commands.shared.{HelpCommandGroup, HelpGroup, SharedOptions}
 import scala.cli.commands.{ScalaCommand, WatchUtil}
 import scala.cli.config.{ConfigDb, Keys}
+import scala.cli.packaging.Library
 import scala.cli.util.ArgHelpers.*
 import scala.cli.util.ConfigDbUtils
+import scala.jdk.CollectionConverters._
 import scala.util.Properties
 
 object Repl extends ScalaCommand[ReplOptions] {
@@ -127,7 +131,7 @@ object Repl extends ScalaCommand[ReplOptions] {
     def doRunRepl(
       buildOptions: BuildOptions,
       artifacts: Artifacts,
-      classDir: Option[os.Path],
+      mainJarOrClassDir: Option[os.Path],
       allowExit: Boolean,
       runMode: RunMode.HasRepl,
       buildOpt: Option[Build.Successful]
@@ -136,7 +140,7 @@ object Repl extends ScalaCommand[ReplOptions] {
         buildOptions,
         programArgs,
         artifacts,
-        classDir,
+        mainJarOrClassDir,
         directories,
         logger,
         allowExit = allowExit,
@@ -154,12 +158,13 @@ object Repl extends ScalaCommand[ReplOptions] {
     def doRunReplFromBuild(
       build: Build.Successful,
       allowExit: Boolean,
-      runMode: RunMode.HasRepl
+      runMode: RunMode.HasRepl,
+      asJar: Boolean
     ): Unit =
       doRunRepl(
         build.options,
         build.artifacts,
-        build.outputOpt,
+        Some(if (asJar) Library.libraryJar(build) else build.output),
         allowExit,
         runMode,
         Some(build)
@@ -210,7 +215,12 @@ object Repl extends ScalaCommand[ReplOptions] {
         for (builds <- res.orReport(logger))
           builds.main match {
             case s: Build.Successful =>
-              doRunReplFromBuild(s, allowExit = false, runMode = runMode(options))
+              doRunReplFromBuild(
+                s,
+                allowExit = false,
+                runMode = runMode(options),
+                asJar = options.shared.asJar
+              )
             case _: Build.Failed    => buildFailed(allowExit = false)
             case _: Build.Cancelled => buildCancelled(allowExit = false)
           }
@@ -234,7 +244,12 @@ object Repl extends ScalaCommand[ReplOptions] {
           .orExit(logger)
       builds.main match {
         case s: Build.Successful =>
-          doRunReplFromBuild(s, allowExit = true, runMode = runMode(options))
+          doRunReplFromBuild(
+            s,
+            allowExit = true,
+            runMode = runMode(options),
+            asJar = options.shared.asJar
+          )
         case _: Build.Failed    => buildFailed(allowExit = true)
         case _: Build.Cancelled => buildCancelled(allowExit = true)
       }
@@ -254,7 +269,7 @@ object Repl extends ScalaCommand[ReplOptions] {
     options: BuildOptions,
     programArgs: Seq[String],
     artifacts: Artifacts,
-    classDir: Option[os.Path],
+    mainJarOrClassDir: Option[os.Path],
     directories: scala.build.Directories,
     logger: Logger,
     allowExit: Boolean,
@@ -324,13 +339,31 @@ object Repl extends ScalaCommand[ReplOptions] {
 
     // TODO Allow to disable printing the welcome banner and the "Loading..." message in Ammonite.
 
-    val rootClasses = classDir
-      .toSeq
-      .flatMap(os.list(_))
-      .filter(_.last.endsWith(".class"))
-      .filter(os.isFile(_)) // just in case
-      .map(_.last.stripSuffix(".class"))
-      .sorted
+    val rootClasses = mainJarOrClassDir match {
+      case None => Nil
+      case Some(dir) if os.isDir(dir) =>
+        os.list(dir)
+          .filter(_.last.endsWith(".class"))
+          .filter(os.isFile(_)) // just in case
+          .map(_.last.stripSuffix(".class"))
+          .sorted
+      case Some(jar) =>
+        var zf: ZipFile = null
+        try {
+          zf = new ZipFile(jar.toIO)
+          zf.entries()
+            .asScala
+            .map(_.getName)
+            .filter(!_.contains("/"))
+            .filter(_.endsWith(".class"))
+            .map(_.stripSuffix(".class"))
+            .toVector
+            .sorted
+        }
+        finally
+          if (zf != null)
+            zf.close()
+    }
     val warnRootClasses = rootClasses.nonEmpty &&
       options.notForBloopOptions.replOptions.useAmmoniteOpt.contains(true)
     if (warnRootClasses)
@@ -354,7 +387,7 @@ object Repl extends ScalaCommand[ReplOptions] {
             replArtifacts.replJavaOpts ++
             options.javaOptions.javaOpts.toSeq.map(_.value.value) ++
             extraProps.toVector.sorted.map { case (k, v) => s"-D$k=$v" },
-          classDir.toSeq ++ replArtifacts.replClassPath,
+          mainJarOrClassDir.toSeq ++ replArtifacts.replClassPath,
           replArtifacts.replMainClass,
           maybeAdaptForWindows(replArgs),
           logger,

modules/cli/src/main/scala/scala/cli/commands/run/Run.scala

@@ -26,6 +26,7 @@ import scala.cli.commands.util.{BuildCommandHelpers, RunHadoop, RunSpark}
 import scala.cli.commands.{CommandUtils, ScalaCommand, SpecificationLevel, WatchUtil}
 import scala.cli.config.{ConfigDb, Keys}
 import scala.cli.internal.ProcUtil
+import scala.cli.packaging.Library.fullClassPathMaybeAsJar
 import scala.cli.util.ArgHelpers.*
 import scala.cli.util.ConfigDbUtils
 import scala.util.{Properties, Try}
@@ -167,7 +168,8 @@ object Run extends ScalaCommand[RunOptions] with BuildCommandHelpers {
             potentialMainClasses,
             runMode,
             showCommand,
-            scratchDirOpt
+            scratchDirOpt,
+            asJar = options.shared.asJar
           )
         }
 
@@ -335,7 +337,8 @@ object Run extends ScalaCommand[RunOptions] with BuildCommandHelpers {
     potentialMainClasses: Seq[String],
     runMode: RunMode,
     showCommand: Boolean,
-    scratchDirOpt: Option[os.Path]
+    scratchDirOpt: Option[os.Path],
+    asJar: Boolean
   ): Either[BuildException, Either[Seq[String], (Process, Option[() => Unit])]] = either {
 
     val mainClassOpt = build.options.mainClass.filter(_.nonEmpty) // trim it too?
@@ -360,7 +363,8 @@ object Run extends ScalaCommand[RunOptions] with BuildCommandHelpers {
       allowExecve,
       runMode,
       showCommand,
-      scratchDirOpt
+      scratchDirOpt,
+      asJar
     )
     value(res)
   }
@@ -394,7 +398,8 @@ object Run extends ScalaCommand[RunOptions] with BuildCommandHelpers {
     allowExecve: Boolean,
     runMode: RunMode,
     showCommand: Boolean,
-    scratchDirOpt: Option[os.Path]
+    scratchDirOpt: Option[os.Path],
+    asJar: Boolean
   ): Either[BuildException, Either[Seq[String], (Process, Option[() => Unit])]] = either {
 
     build.options.platform.value match {
@@ -539,7 +544,7 @@ object Run extends ScalaCommand[RunOptions] with BuildCommandHelpers {
               val command = Runner.jvmCommand(
                 build.options.javaHome().value.javaCommand,
                 allJavaOpts,
-                build.fullClassPath,
+                build.fullClassPathMaybeAsJar(asJar),
                 mainClass,
                 args,
                 extraEnv = pythonExtraEnv,
@@ -552,7 +557,7 @@ object Run extends ScalaCommand[RunOptions] with BuildCommandHelpers {
               val proc = Runner.runJvm(
                 build.options.javaHome().value.javaCommand,
                 allJavaOpts,
-                build.fullClassPath,
+                build.fullClassPathMaybeAsJar(asJar),
                 mainClass,
                 args,
                 logger,

modules/cli/src/main/scala/scala/cli/commands/shared/SharedOptions.scala

@@ -140,6 +140,12 @@ final case class SharedOptions(
   @Tag(tags.must)
     resourceDirs: List[String] = Nil,
 
+  @Hidden
+  @Group(HelpGroup.Java.toString)
+  @HelpMessage("Put project in class paths as a JAR rather than as a byte code directory")
+  @Tag(tags.experimental)
+    asJar: Boolean = false,
+
   @Group(HelpGroup.Scala.toString)
   @HelpMessage("Specify platform")
   @ValueDescription("scala-js|scala-native|jvm")

modules/cli/src/main/scala/scala/cli/commands/test/Test.scala

@@ -21,6 +21,7 @@ import scala.cli.commands.shared.{HelpCommandGroup, HelpGroup, SharedOptions}
 import scala.cli.commands.update.Update
 import scala.cli.commands.{CommandUtils, ScalaCommand, SpecificationLevel, WatchUtil}
 import scala.cli.config.{ConfigDb, Keys}
+import scala.cli.packaging.Library.fullClassPathMaybeAsJar
 import scala.cli.util.ArgHelpers.*
 import scala.cli.util.ConfigDbUtils
 
@@ -109,7 +110,8 @@ object Test extends ScalaCommand[TestOptions] {
               options.requireTests,
               args.unparsed,
               logger,
-              allowExecve = allowExit && buildsLen <= 1
+              allowExecve = allowExit && buildsLen <= 1,
+              asJar = options.shared.asJar
             )
             if (printBeforeAfterMessages && idx < buildsLen - 1)
               System.err.println()
@@ -180,6 +182,7 @@ object Test extends ScalaCommand[TestOptions] {
     requireTests: Boolean,
     args: Seq[String],
     logger: Logger,
+    asJar: Boolean,
     allowExecve: Boolean
   ): Either[BuildException, Int] = either {
 
@@ -231,7 +234,7 @@ object Test extends ScalaCommand[TestOptions] {
           }.flatten
         }
       case Platform.JVM =>
-        val classPath = build.fullClassPath
+        val classPath = build.fullClassPathMaybeAsJar(asJar)
 
         val testFrameworkOpt0 = testFrameworkOpt.orElse {
           findTestFramework(classPath.map(_.toNIO), logger)

modules/cli/src/main/scala/scala/cli/packaging/Library.scala

@@ -82,4 +82,11 @@ object Library {
     finally if (zos != null) zos.close()
   }
 
+  extension (build: Build.Successful) {
+    def fullClassPathAsJar: Seq[os.Path] =
+      Seq(libraryJar(build)) ++ build.dependencyClassPath
+    def fullClassPathMaybeAsJar(asJar: Boolean): Seq[os.Path] =
+      if (asJar) fullClassPathAsJar else build.fullClassPath
+  }
+
 }

modules/integration/src/test/scala/scala/cli/integration/CompileTestsDefault.scala

@@ -1,6 +1,9 @@
 package scala.cli.integration
 
 import com.eed3si9n.expecty.Expecty.expect
+
+import java.io.File
+
 class CompileTestsDefault extends CompileTestDefinitions(scalaVersionOpt = None) {
   test("render explain message") {
     val fileName = "Hello.scala"
@@ -20,4 +23,36 @@ class CompileTestsDefault extends CompileTestDefinitions(scalaVersionOpt = None)
       expect(out.contains("Explanation"))
     }
   }
+
+  test("as jar") {
+    val inputs = TestInputs(
+      os.rel / "Foo.scala" ->
+        """object Foo {
+          |  def n = 2
+          |}
+          |""".stripMargin
+    )
+    inputs.fromRoot { root =>
+      val out = os.proc(TestUtil.cli, "compile", extraOptions, ".", "--print-class-path")
+        .call(cwd = root)
+        .out.trim()
+      val cp = out.split(File.pathSeparator).toVector.map(os.Path(_, root))
+      expect(cp.headOption.exists(os.isDir(_)))
+      expect(cp.drop(1).forall(os.isFile(_)))
+
+      val asJarOut = os.proc(
+        TestUtil.cli,
+        "--power",
+        "compile",
+        extraOptions,
+        ".",
+        "--print-class-path",
+        "--as-jar"
+      )
+        .call(cwd = root)
+        .out.trim()
+      val asJarCp = asJarOut.split(File.pathSeparator).toVector.map(os.Path(_, root))
+      expect(asJarCp.forall(os.isFile(_)))
+    }
+  }
 }

modules/integration/src/test/scala/scala/cli/integration/ReplTestsDefault.scala

@@ -1,7 +1,63 @@
 package scala.cli.integration
 
+import com.eed3si9n.expecty.Expecty.expect
+
+import scala.util.Properties
+
 // format: off
 class ReplTestsDefault extends ReplTestDefinitions(
   scalaVersionOpt = None
-)
-// format: on
+) {
+  // format: on
+
+  test("as jar") {
+    val inputs = TestInputs(
+      os.rel / "CheckCp.scala" ->
+        """//> using lib "com.lihaoyi::os-lib:0.9.1"
+          |package checkcp
+          |object CheckCp {
+          |  def hasDir: Boolean =
+          |    sys.props("java.class.path")
+          |      .split(java.io.File.pathSeparator)
+          |      .toVector
+          |      .map(os.Path(_, os.pwd))
+          |      .exists(os.isDir(_))
+          |}
+          |""".stripMargin
+    )
+
+    inputs.fromRoot { root =>
+      val ammArgs = Seq(
+        "-c",
+        """println("hasDir=" + checkcp.CheckCp.hasDir)"""
+      )
+        .map {
+          if (Properties.isWin)
+            a => if (a.contains(" ")) "\"" + a.replace("\"", "\\\"") + "\"" else a
+          else
+            identity
+        }
+        .flatMap(arg => Seq("--ammonite-arg", arg))
+
+      val output =
+        os.proc(TestUtil.cli, "--power", "repl", ".", TestUtil.extraOptions, "--ammonite", ammArgs)
+          .call(cwd = root)
+          .out.trim()
+      expect(output == "hasDir=true")
+
+      val asJarOutput = os.proc(
+        TestUtil.cli,
+        "--power",
+        "repl",
+        ".",
+        TestUtil.extraOptions,
+        "--ammonite",
+        ammArgs,
+        "--as-jar"
+      )
+        .call(cwd = root)
+        .out.trim()
+      expect(asJarOutput == "hasDir=false")
+    }
+  }
+}