some of the help text not rendered properly when option is EnumFlag

[bkhouri]

If I have

enum CoverageFormat: String, ExpressibleByArgument, CaseIterable {
    case json
    case html

    var defaultValueDescription: String {
        switch self {
            case .json: "Produces a JSON coverage report."
            case .html: "Produces an HTML report producd by llvm-cov.  The HTML report can be configured using a reponse file stored in the project repository. See 'TODO' for more."
        }
    }
}

And in my AsyncParseableCommand , I have

    @Option(
        help: "Format of the code coverage output. One of 'json' or 'html'.",
    )
    var format: [CoverageFormat] = [.json]

running the --help option produces the following

  --codecov-format, --code-coverage-format, --coverage-format <format>
                          (values: json, html; default: Produces a JSON coverage report.)

Replace this paragraph with a short description of the incorrect incorrect behavior. If this is a regression, please note the last version that the behavior was correct in addition to your current version.

ArgumentParser version: main branch at commit ID 04695ec5448962bcd5e4616ed184b8a2168751e7
Swift version:

❯ swift --version            
Apple Swift version 6.2 (swift-6.2-RELEASE)
Target: arm64-apple-macosx26.0
Build config: +assertions

Checklist

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

Steps to Reproduce

A minimal reproducible case has been added here: https://github.com/bkhouri/sap-reproducible-example.git

1. clone https://github.com/bkhouri/sap-reproducible-example.git
2. run swift run sap-reproducible-example --help or follow the instructions in the README.md

Expected behavior

The --help output for the options that is an array of enum display the proper default: value, and also lists the description of each enum item. it addition, which may be outside the scope of this issue, would be a help string that automatically indicate the --format-as-array can be specified multiple times.

That is, the output looks something like

  --format-as-array <format>
                          Specify the output format. Available options: json, xml, yaml, plain (default: [plain])
        json              - Output in JSON format
        xml               - Output in XML format
        yaml              - Output in YAML format
        plain             - Output in plain text format

Actual behavior

  --format-as-array <format-as-array>
                          Specify the output format. Available options: json, xml, yaml, plain (values: json, xml, yaml, plain; default: Output in plain text
                          format)

[rgoldberg]

A more concise output would probably be preferable:

  --format-as-array <format>  Specify the output format.
        json   - Output in JSON format
        xml    - Output in XML format
        yaml   - Output in YAML format
        plain  - Output in plain text format (default)

[bkhouri]

@rgoldberg: as long as the concise output also display the default value :)