Add help for repl, scalafmt and scaladoc

modules/cli-options/src/main/scala/scala/cli/commands/HelpGroupOptions.scala

@@ -10,7 +10,20 @@ case class HelpGroupOptions(
   @HelpMessage("Show options for ScalaJS")
   helpJs: Boolean = false,
   @HelpMessage("Show options for ScalaNative")
-  helpNative: Boolean = false
+  helpNative: Boolean = false,
+  @HelpMessage("Show options for scaladoc")
+  @Name("scaladocHelp")
+  @Name("docHelp")
+  @Name("helpDoc")
+  helpScaladoc: Boolean = false,
+  @HelpMessage("Show options for scalafmt")
+  @Name("replHelp")
+  helpRepl: Boolean = false,
+  @HelpMessage("Show options for scalafmt")
+  @Name("scalafmtHelp")
+  @Name("fmtHelp")
+  @Name("helpFmt")
+  helpScalafmt: Boolean = false
 ) {
 
   private def printHelpWithGroup(help: Help[_], helpFormat: HelpFormat, group: String): Nothing = {

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

@@ -7,14 +7,18 @@ import caseapp.core.help.{Help, HelpFormat}
 import caseapp.core.parser.Parser
 import caseapp.core.util.Formatter
 import caseapp.core.{Arg, Error, RemainingArgs}
+import dependency.*
 
 import scala.annotation.tailrec
+import scala.build.EitherCps.{either, value}
 import scala.build.compiler.SimpleScalaCompiler
-import scala.build.internal.Constants
+import scala.build.errors.BuildException
+import scala.build.internal.{Constants, Runner}
 import scala.build.options.{BuildOptions, Scope}
-import scala.cli.commands.util.CommandHelpers
+import scala.build.{Artifacts, Positioned, ReplArtifacts}
 import scala.cli.commands.util.ScalacOptionsUtil.*
 import scala.cli.commands.util.SharedOptionsUtil.*
+import scala.cli.commands.util.{CommandHelpers, FmtOptionsUtil}
 import scala.cli.{CurrentParams, ScalaCli}
 import scala.util.{Properties, Try}
 
@@ -23,6 +27,7 @@ abstract class ScalaCommand[T](implicit myParser: Parser[T], help: Help[T])
 
   def sharedOptions(t: T): Option[SharedOptions] = // hello borked unused warning
     None
+
   override def hasFullHelp = true
 
   override def parser: Parser[T] =
@@ -31,6 +36,7 @@ abstract class ScalaCommand[T](implicit myParser: Parser[T], help: Help[T])
   def isRestricted: Boolean = false
 
   protected var argvOpt = Option.empty[Array[String]]
+
   override def setArgv(argv: Array[String]): Unit = {
     argvOpt = Some(argv)
   }
@@ -39,6 +45,7 @@ abstract class ScalaCommand[T](implicit myParser: Parser[T], help: Help[T])
   protected def progName: String = ScalaCli.progName
 
   // TODO Manage to have case-app give use the exact command name that was used instead
+
   /** The actual sub-command name that was used. If the sub-command name is a list of strings, space
     * is used as the separator. If [[argvOpt]] hasn't been defined, it defaults to [[name]].
     */
@@ -84,6 +91,7 @@ abstract class ScalaCommand[T](implicit myParser: Parser[T], help: Help[T])
     new Completer[T] {
       def optionName(prefix: String, state: Option[T]): List[CompletionItem] =
         parent.optionName(prefix, state)
+
       def optionValue(arg: Arg, prefix: String, state: Option[T]): List[CompletionItem] = {
         val candidates = arg.name.name match {
           case "dependency" =>
@@ -117,6 +125,7 @@ abstract class ScalaCommand[T](implicit myParser: Parser[T], help: Help[T])
         }
         candidates ++ parent.optionValue(arg, prefix, state)
       }
+
       def argument(prefix: String, state: Option[T]): List[CompletionItem] =
         parent.argument(prefix, state)
     }
@@ -128,6 +137,7 @@ abstract class ScalaCommand[T](implicit myParser: Parser[T], help: Help[T])
 
   /** Print `scalac` output if passed options imply no inputs are necessary and raw `scalac` output
     * is required instead. (i.e. `--scalac-option -help`)
+    *
     * @param options
     *   command options
     */
@@ -159,6 +169,74 @@ abstract class ScalaCommand[T](implicit myParser: Parser[T], help: Help[T])
       sys.exit(exitCode)
     }
 
+  def maybePrintToolsHelp(options: T, buildOptions: BuildOptions): Unit =
+    for {
+      shared <- sharedOptions(options)
+      logger = shared.logger
+      artifacts      <- buildOptions.artifacts(logger, Scope.Main).toOption
+      scalaArtifacts <- artifacts.scalaOpt
+      scalaParams = scalaArtifacts.params
+      if shared.helpGroups.helpScaladoc || shared.helpGroups.helpRepl || shared.helpGroups.helpScalafmt
+    } {
+      val exitCode: Either[BuildException, Int] = either {
+        val (classPath: Seq[os.Path], mainClass: String) =
+          if (shared.helpGroups.helpScaladoc) {
+            val docArtifacts = value {
+              Artifacts.fetch(
+                Positioned.none(Seq(dep"org.scala-lang::scaladoc:${scalaParams.scalaVersion}")),
+                buildOptions.finalRepositories,
+                Some(scalaParams),
+                logger,
+                buildOptions.finalCache,
+                None
+              )
+            }
+            (docArtifacts.files.map(os.Path(_, os.pwd)), "dotty.tools.scaladoc.Main")
+          }
+          else if (shared.helpGroups.helpRepl) {
+            val initialBuildOptions = buildOptionsOrExit(options)
+            val artifacts = initialBuildOptions.artifacts(logger, Scope.Main).orExit(logger)
+            val replArtifacts = value {
+              ReplArtifacts.default(
+                scalaParams,
+                artifacts.userDependencies,
+                Nil,
+                logger,
+                buildOptions.finalCache,
+                Nil,
+                None
+              )
+            }
+            (replArtifacts.replClassPath, replArtifacts.replMainClass)
+          }
+          else {
+            val fmtArtifacts = value {
+              Artifacts.fetch(
+                Positioned.none(Seq(
+                  dep"${Constants.scalafmtOrganization}:${Constants.scalafmtName}:${Constants.defaultScalafmtVersion}"
+                )),
+                buildOptions.finalRepositories,
+                Some(scalaParams),
+                logger,
+                buildOptions.finalCache,
+                None
+              )
+            }
+            (fmtArtifacts.files.map(os.Path(_, os.pwd)), "org.scalafmt.cli.Cli")
+          }
+        val retCode = Runner.runJvm(
+          buildOptions.javaHome().value.javaCommand,
+          Nil,
+          classPath,
+          mainClass,
+          Seq("-help"),
+          logger
+        ).waitFor()
+        retCode
+      }
+      sys.exit(exitCode.orExit(logger))
+    }
+
   override def helpFormat: HelpFormat =
     HelpFormat.default()
       .withSortedGroups(Some(Seq(
@@ -251,7 +329,10 @@ abstract class ScalaCommand[T](implicit myParser: Parser[T], help: Help[T])
   final override def run(options: T, remainingArgs: RemainingArgs): Unit = {
     verbosity(options).foreach(v => CurrentParams.verbosity = v)
     maybePrintGroupHelp(options)
-    buildOptions(options).foreach(bo => maybePrintSimpleScalacOutput(options, bo))
+    buildOptions(options).foreach { bo =>
+      maybePrintSimpleScalacOutput(options, bo)
+      maybePrintToolsHelp(options, bo)
+    }
     runCommand(options, remainingArgs)
   }
 }

website/docs/reference/cli-options.md

@@ -364,6 +364,24 @@ Show options for ScalaJS
 
 Show options for ScalaNative
 
+### `--help-scaladoc`
+
+Aliases: `--scaladoc-help`, `--doc-help`, `--help-doc`
+
+Show options for scaladoc
+
+### `--help-repl`
+
+Aliases: `--repl-help`
+
+Show options for scalafmt
+
+### `--help-scalafmt`
+
+Aliases: `--scalafmt-help`, `--fmt-help`, `--help-fmt`
+
+Show options for scalafmt
+
 ## Install completions options
 
 Available in commands:

website/docs/reference/scala-command/cli-options.md

@@ -314,6 +314,24 @@ Show options for ScalaJS
 
 Show options for ScalaNative
 
+### `--help-scaladoc`
+
+Aliases: `--scaladoc-help`, `--doc-help`, `--help-doc`
+
+Show options for scaladoc
+
+### `--help-repl`
+
+Aliases: `--repl-help`
+
+Show options for scalafmt
+
+### `--help-scalafmt`
+
+Aliases: `--scalafmt-help`, `--fmt-help`, `--help-fmt`
+
+Show options for scalafmt
+
 ## Install completions options
 
 Available in commands: