Add more interactive install-home command

modules/cli/src/main/scala/scala/cli/ScalaCli.scala

@@ -31,7 +31,8 @@ object ScalaCli extends CommandsEntryPoint {
     Package,
     Run,
     SetupIde,
-    Test
+    Test,
+    Version
   )
 
   lazy val progName                 = (new Argv0).get("scala-cli")

modules/cli/src/main/scala/scala/cli/commands/InstallHome.scala

@@ -4,60 +4,98 @@ import caseapp._
 import coursier.env.{EnvironmentUpdate, ProfileUpdater}
 
 import scala.io.StdIn.readLine
-import scala.util.Properties
+import scala.util.{Properties, Try}
 
 object InstallHome extends ScalaCommand[InstallHomeOptions] {
   override def hidden: Boolean = true
-  def run(options: InstallHomeOptions, args: RemainingArgs): Unit = {
 
-    val binDirPath      = scala.build.Directories.default().binRepoDir
-    val scalaCliBinPath = binDirPath / "scala-cli"
-
-    if (os.exists(scalaCliBinPath))
-      if (options.force) os.remove.all(scalaCliBinPath)
-      else if (coursier.paths.Util.useAnsiOutput()) {
-        println(
-          "scala-cli already exists. Do you want to override it [Y/n]"
-        )
-        val replace = readLine()
-        if (replace == "Y")
-          os.remove.all(scalaCliBinPath)
-        else {
-          System.err.println("Abort")
-          sys.exit(1)
-        }
-      }
-      else {
-        System.err.println(
-          s"Error: scala-cli already exists. Pass -f or --force to force erasing it."
-        )
+  private def isOutOfDate(newVersion: String, oldVersion: String): Boolean = {
+    import coursier.core.Version
+
+    Version(newVersion) > Version(oldVersion)
+  }
+
+  private def logEqual(version: String) = {
+    System.err.println(
+      s"Scala-cli $version is already installed and up-to-date."
+    )
+    sys.exit(0)
+  }
+
+  private def logUpdate(env: Boolean, newVersion: String, oldVersion: String) =
+    if (!env) println(
+      s"""scala-cli $oldVersion is already installed and out-of-date.
+         |scala-cli will be updated to version $newVersion
+         |""".stripMargin
+    )
+
+  private def logDowngrade(env: Boolean, newVersion: String, oldVersion: String) =
+    if (!env && coursier.paths.Util.useAnsiOutput()) {
+      println(s"scala-cli $oldVersion is already installed and up-to-date.")
+      println(s"Do you want to downgrade scala-cli to version $newVersion [Y/n]")
+      val response = readLine()
+      if (response != "Y") {
+        System.err.println("Abort")
         sys.exit(1)
       }
+    }
+    else {
+      System.err.println(
+        s"Error: scala-cli is already installed $oldVersion and up-to-date. Downgrade to $newVersion pass -f or --force."
+      )
+      sys.exit(1)
+    }
+
+  def run(options: InstallHomeOptions, args: RemainingArgs): Unit = {
+
+    val binDirPath =
+      options.binDirPath.getOrElse(scala.build.Directories.default().binRepoDir / "scala-cli")
+    val newScalaCliBinPath = os.Path(options.scalaCliBinaryPath, os.pwd)
+
+    val newVersion: String =
+      os.proc(newScalaCliBinPath, "version").call(cwd = os.pwd).out.text.trim
+
+    // Backward compatibility - previous versions not have the `--version` parameter
+    val oldVersion: String = Try {
+      os.proc(binDirPath / options.binaryName, "version").call(cwd = os.pwd).out.text.trim
+    }.toOption.getOrElse("0.0.0")
+
+    if (os.exists(binDirPath))
+      if (options.force) () // skip logging
+      else if (newVersion == oldVersion) logEqual(newVersion)
+      else if (isOutOfDate(newVersion, oldVersion))
+        logUpdate(options.env, newVersion, oldVersion)
+      else logDowngrade(options.env, newVersion, oldVersion)
+
+    os.remove.all(binDirPath)
 
     os.copy(
-      from = os.Path(options.scalaCliBinaryPath, os.pwd),
-      to = scalaCliBinPath / "scala-cli",
+      from = newScalaCliBinPath,
+      to = binDirPath / options.binaryName,
       createFolders = true
     )
     if (!Properties.isWin)
-      os.perms.set(scalaCliBinPath / "scala-cli", os.PermSet.fromString("rwxrwxr-x"))
+      os.perms.set(binDirPath / options.binaryName, os.PermSet.fromString("rwxr-xr-x"))
 
-    val update = EnvironmentUpdate(Nil, Seq("PATH" -> scalaCliBinPath.toString()))
+    if (options.env)
+      println(s"""export PATH="$binDirPath:$$PATH"""")
+    else {
 
-    val didUpdate =
-      if (Properties.isWin) {
-        val updater = CustomWindowsEnvVarUpdater().withUseJni(Some(coursier.paths.Util.useJni()))
-        updater.applyUpdate(update)
-      }
-      else {
-        val updater = ProfileUpdater()
-        updater.applyUpdate(update)
-      }
+      val update = EnvironmentUpdate(Nil, Seq("PATH" -> binDirPath.toString()))
+
+      val didUpdate =
+        if (Properties.isWin) {
+          val updater = CustomWindowsEnvVarUpdater().withUseJni(Some(coursier.paths.Util.useJni()))
+          updater.applyUpdate(update)
+        }
+        else {
+          val updater = ProfileUpdater()
+          updater.applyUpdate(update)
+        }
 
-    if (didUpdate)
-      println("Successfully installed scala-cli")
-    else
-      System.err.println(s"scala-cli is already installed")
+      if (didUpdate) "Profile was updated"
 
+      println(s"Successfully installed scala-cli $newVersion")
+    }
   }
 }

modules/cli/src/main/scala/scala/cli/commands/InstallHomeOptions.scala

@@ -11,8 +11,16 @@ final case class InstallHomeOptions(
   @Name("f")
   @HelpMessage("Overwrite scala-cli if exists")
     force: Boolean = false,
-)
-// format: on
+  @HelpMessage("Binary name")
+    binaryName: String = "scala-cli",
+  @HelpMessage("Print the env update")
+    env: Boolean = false,
+  @HelpMessage("Binary directory")
+    binDir: Option[String] = None
+) {
+  // format: on
+  lazy val binDirPath = binDir.map(os.Path(_, os.pwd))
+}
 
 object InstallHomeOptions {
   implicit lazy val parser: Parser[InstallHomeOptions] = Parser.derive

modules/cli/src/main/scala/scala/cli/commands/SharedCompilationServerOptions.scala

@@ -2,7 +2,6 @@ package scala.cli.commands
 
 import caseapp._
 import com.google.gson.Gson
-import coursier.core.Version
 
 import java.io.{BufferedReader, File, FileReader}
 import java.nio.file.{AtomicMoveNotSupportedException, FileAlreadyExistsException, Files}
@@ -168,7 +167,9 @@ final case class SharedCompilationServerOptions(
     parseDuration("connection server startup timeout", bloopStartupTimeout)
 
   def minimumBloopVersion = Constants.bloopVersion
-  def acceptBloopVersion  = Some((v: String) => Version(v) < Version(minimumBloopVersion))
+
+  import coursier.core.Version
+  def acceptBloopVersion = Some((v: String) => Version(v) < Version(minimumBloopVersion))
 
   def bloopDefaultJvmOptions(logger: Logger): List[String] = {
     val file = new File(bloopGlobalOptionsFile)

modules/cli/src/main/scala/scala/cli/commands/Version.scala

@@ -0,0 +1,12 @@
+package scala.cli.commands
+
+import caseapp._
+
+import scala.build.internal.Constants
+
+object Version extends ScalaCommand[VersionOptions] {
+  override def group = "Miscellaneous"
+  def run(options: VersionOptions, args: RemainingArgs): Unit = {
+    println(Constants.version)
+  }
+}

modules/cli/src/main/scala/scala/cli/commands/VersionOptions.scala

@@ -0,0 +1,11 @@
+package scala.cli.commands
+
+import caseapp._
+
+@HelpMessage("Print scala-cli version")
+final case class VersionOptions()
+
+object VersionOptions {
+  implicit lazy val parser: Parser[VersionOptions] = Parser.derive
+  implicit lazy val help: Help[RunOptions]         = Help.derive
+}

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

@@ -0,0 +1,111 @@
+package scala.cli.integration
+
+import com.eed3si9n.expecty.Expecty.expect
+
+import scala.util.Properties
+
+class InstallHomeTests extends munit.FunSuite {
+
+  val firstVersion            = "0.0.1"
+  val secondVersion           = "0.0.2"
+  val dummyScalaCliFirstName  = "DummyScalaCli-1.scala"
+  val dummyScalaCliSecondName = "DummyScalaCli-2.scala"
+  val dummyScalaCliBinName    = "scala-cli-dummy-test"
+  val testInputs = TestInputs(
+    Seq(
+      os.rel / dummyScalaCliFirstName ->
+        s"""
+           |object DummyScalaCli extends App {
+           |  println(\"$firstVersion\")
+           |}""".stripMargin,
+      os.rel / dummyScalaCliSecondName ->
+        s"""
+           |object DummyScalaCli extends App {
+           |  println(\"$secondVersion\")
+           |}""".stripMargin
+    )
+  )
+
+  private def packageDummyScalaCli(root: os.Path, dummyScalaCliFileName: String, output: String) = {
+    // format: off
+    val cmd = Seq[os.Shellable](
+      TestUtil.cli, "package", dummyScalaCliFileName, "-o", output
+    )
+    // format: on
+    os.proc(cmd).call(
+      cwd = root,
+      stdin = os.Inherit,
+      stdout = os.Inherit
+    )
+  }
+
+  private def installScalaCli(
+    root: os.Path,
+    binVersion: String,
+    binDirPath: os.Path,
+    force: Boolean
+  ) = {
+    // format: off
+    val cmdInstallVersion = Seq[os.Shellable](
+      TestUtil.cli, "install-home", 
+      "--env", 
+      "--scala-cli-binary-path", binVersion , 
+      "--binary-name", dummyScalaCliBinName, 
+      "--bin-dir", binDirPath
+    ) ++ (if(force) Seq[os.Shellable]("--force") else Seq.empty)
+    // format: on
+    os.proc(cmdInstallVersion).call(
+      cwd = root,
+      stdin = os.Inherit,
+      stdout = os.Inherit
+    )
+  }
+
+  def runInstallHome(): Unit = {
+
+    testInputs.fromRoot { root =>
+      val binDirPath = root / ".scala" / "scala-cli"
+
+      val binDummyScalaCliFirst  = dummyScalaCliFirstName.stripSuffix(".scala").toLowerCase
+      val binDummyScalaCliSecond = dummyScalaCliSecondName.stripSuffix(".scala").toLowerCase
+
+      packageDummyScalaCli(root, dummyScalaCliFirstName, binDummyScalaCliFirst)
+      packageDummyScalaCli(root, dummyScalaCliSecondName, binDummyScalaCliSecond)
+
+      // install 1 version
+      installScalaCli(root, binDummyScalaCliFirst, binDirPath, force = true)
+
+      println(binDirPath / dummyScalaCliBinName)
+
+      val v1Install = os.proc(binDirPath / dummyScalaCliBinName).call(
+        cwd = root,
+        stdin = os.Inherit
+      ).out.text.trim
+      expect(v1Install == firstVersion)
+
+      // update to 2 version
+      installScalaCli(root, binDummyScalaCliSecond, binDirPath, force = false)
+
+      val v2Update = os.proc(binDirPath / dummyScalaCliBinName).call(
+        cwd = root,
+        stdin = os.Inherit
+      ).out.text.trim
+      expect(v2Update == secondVersion)
+
+      // downgrade to 1 version with force
+      installScalaCli(root, binDummyScalaCliFirst, binDirPath, force = true)
+
+      val v1Downgrade = os.proc(binDirPath / dummyScalaCliBinName).call(
+        cwd = root,
+        stdin = os.Inherit
+      ).out.text.trim
+      expect(v1Downgrade == firstVersion)
+    }
+  }
+
+  if (!Properties.isWin && TestUtil.isCI)
+    test("updating and downgrading dummy scala-cli using install-home command") {
+      runInstallHome()
+    }
+
+}

website/docs/reference/cli-options.md

@@ -285,6 +285,7 @@ Available in commands:
 - [`run`](./commands#run)
 - [`setup-ide`](./commands#setup-ide)
 - [`test`](./commands#test)
+- [`version`](./commands#version)
 
 
 <!-- Automatically generated, DO NOT EDIT MANUALLY -->
@@ -343,6 +344,18 @@ Aliases: `-f`
 
 Overwrite scala-cli if exists
 
+#### `--binary-name`
+
+Binary name
+
+#### `--env`
+
+Print the env update
+
+#### `--bin-dir`
+
+Binary directory
+
 ## Java options
 
 Available in commands:

website/docs/reference/commands.md

@@ -216,6 +216,10 @@ Accepts options:
 - [test](./cli-options.md#test-options)
 - [watch](./cli-options.md#watch-options)
 
+## `version`
+
+Print scala-cli version
+
 ## Hidden commands
 
 ### `add-path`