Modifying help flag names does not work for subcommands

[paulofaria]

modifying-the-help-flag-names does not work for subcommands.

Possibly related to #36.

Checklist

• If possible, I've reproduced the issue using the master branch of this package
• I've searched for existing GitHub issues

Steps to Reproduce

struct FeatherFeed : ParsableCommand {
    static var configuration = CommandConfiguration(
        abstract: "FeatherFeed backend application.",
        subcommands: [Run.self],
        defaultSubcommand: Run.self
    )

    ...
}


extension FeatherFeed {
    struct Run : ParsableCommand {
        static var configuration = CommandConfiguration(
            abstract: "Runs the FeatherFeed application.",
            helpNames: [.long, .customShort("?")]
        )
        
        @Option(name: .shortAndLong, help: "The host the server will run on.")
        var host: String = "::1"
        
        @Option(name: .shortAndLong, help: "The port the server will run on.")
        var port: Int = 8080
    
        ...
    }
}

Expected behavior

> swift run feather-feed run --help
OVERVIEW: Runs the FeatherFeed application.

USAGE: feather-feed run [--host <host>] [--port <port>]

OPTIONS:
  -h, --host <host>       The host the server will run on. (default: ::1)
  -p, --port <port>       The port the server will run on. (default: 8080)
  -?, --help              Show help information.

Actual behavior

> swift run feather-feed run --help
OVERVIEW: Runs the FeatherFeed application.

USAGE: feather-feed run [--host <host>] [--port <port>]

OPTIONS:
  -h, --host <host>       The host the server will run on. (default: ::1)
  -p, --port <port>       The port the server will run on. (default: 8080)
  -h, --help              Show help information.

Discussion

Apparently subcommands are inheriting the helpNames configuration from the parent command. If I change helpNames for the FeatherFeed command, the Run subcommand inherits the -? flag.

[Zoha131]

@natecook1000 I have a question regarding this issue. Should Subcommands inherit helpNames from its parent if not modified? Or if not modified, helpNames for Subcommands would be -h, --help regardless how it is defined in the parent command?

[natecook1000]

I would think an inheritance model would make the most sense, and would be compatible with the current system. So subcommands get whatever their super-commands have specified, unless they specify their own. I think this means that we’d need to change the property to be optional and have it default to nil, however.