Show child's help when parent options are valid

zio-cli/shared/src/main/scala/zio/cli/Command.scala

@@ -293,13 +293,9 @@ object Command {
  args: List[String],
  conf: CliConfig
  ): IO[ValidationError, CommandDirective[(A, B)]] = {
- val helpDirectiveForChild = {
- val safeTail = args match {
- case Nil => Nil
- case _ :: tail => tail
- }
+ val helpDirectiveForChild =
  child
- .parse(safeTail, conf)
+ .parse(args.tail, conf)
  .collect(ValidationError(ValidationErrorType.InvalidArgument, HelpDoc.empty)) {
  case CommandDirective.BuiltIn(BuiltInOption.ShowHelp(synopsis, helpDoc)) =>
  val parentName = names.headOption.getOrElse("")
@@ -310,22 +306,16 @@ object Command {
  )
  }
  }
- }
 
  val helpDirectiveForParent =
  ZIO.succeed(CommandDirective.builtIn(BuiltInOption.ShowHelp(synopsis, helpDoc)))
 
- val wizardDirectiveForChild = {
- val safeTail = args match {
- case Nil => Nil
- case _ :: tail => tail
- }
+ val wizardDirectiveForChild =
  child
- .parse(safeTail, conf)
+ .parse(args.tail, conf)
  .collect(ValidationError(ValidationErrorType.InvalidArgument, HelpDoc.empty)) {
  case directive @ CommandDirective.BuiltIn(BuiltInOption.ShowWizard(_)) => directive
  }
- }
 
  val wizardDirectiveForParent =
  ZIO.succeed(CommandDirective.builtIn(BuiltInOption.ShowWizard(self)))
@@ -355,7 +345,15 @@ object Command {
  )
  case other: ValidationError => other
  },
- _.map((a, _))
+ _.map((a, _)).mapBuiltIn {
+ case BuiltInOption.ShowHelp(synopsis, helpDoc) =>
+ val parentName = names.headOption.getOrElse("")
+ BuiltInOption.ShowHelp(
+ UsageSynopsis.Named(List(parentName), None) + synopsis,
+ helpDoc
+ )
+ case builtIn => builtIn
+ }
  )
  case _ =>
  helpDirectiveForParent

zio-cli/shared/src/main/scala/zio/cli/CommandDirective.scala

@@ -8,6 +8,13 @@ sealed trait CommandDirective[+A] { self =>
  case x @ BuiltIn(_) => x
  case UserDefined(leftover, value) => CommandDirective.UserDefined(leftover, f(value))
  }
+
+ def mapBuiltIn(f: BuiltInOption => BuiltInOption): CommandDirective[A] =
+ self match {
+ case BuiltIn(x) => BuiltIn(f(x))
+ case x @ UserDefined(_, _) => x
+ }
+
 }
 object CommandDirective {
  final case class BuiltIn(option: BuiltInOption) extends CommandDirective[Nothing]

zio-cli/shared/src/main/scala/zio/cli/Options.scala

@@ -303,7 +303,7 @@ object Options extends OptionsPlatformSpecific {
  }
 
  /**
- * `Options.validate` parses `args` for `options and returns an `Option[ValidationError]`, the leftover arguments and
+ * `Options.validate` parses `args` for options and returns an `Option[ValidationError]`, the leftover arguments and
  * the constructed value of type `A`. The possible error inside `Option[ValidationError]` would only be triggered if
  * there is an error when parsing the `Args` of a `Command`. This is because `ValidationErrors` are used to control
  * the end of the args corresponding to options.

zio-cli/shared/src/test/scala/zio/cli/CommandSpec.scala

@@ -303,6 +303,13 @@ object CommandSpec extends ZIOSpecDefault {
 
  val params8 = List("command", "-af", "asdgf", "--wizard")
 
+ val commandWithSubcommand = Command("test", Options.text("param")).subcommands(
+ Command("a")
+ .subcommands(
+ Command("b")
+ )
+ )
+
  Vector(
  test("trigger built-in options that are alone")(
  assertZIO(command.parse(params1, CliConfig.default).map(directiveType _))(equalTo("help")) &&
@@ -319,7 +326,23 @@ object CommandSpec extends ZIOSpecDefault {
  ),
  test("triggering wizard not alone")(
  assertZIO(command.parse(params8, CliConfig.default).map(directiveType _))(equalTo("wizard"))
- )
+ ),
+ test("trigger child command's help if parent command is correct") {
+
+ def extractHelp(d: CommandDirective[String]): Option[(String, String)] = d match {
+ case CommandDirective.BuiltIn(BuiltInOption.ShowHelp(synopsis, doc)) =>
+ Some((synopsis.helpDoc.toPlaintext(), doc.toPlaintext()))
+ case _ => None
+ }
+
+ for {
+ help1 <- commandWithSubcommand
+ .parse(List("test", "--param", "text", "a", "--help"), CliConfig.default)
+ .map(extractHelp)
+ help2 <- commandWithSubcommand.parse(List("test", "a", "--help"), CliConfig.default).map(extractHelp)
+
+ } yield assertTrue(help1 == help2)
+ }
  )
  },
  test("cmd opts -- args") {