GNU-style triple-dash option (---gnu-style-hidden-option) no longer work in 13.0.0

[wataash]

In 12.1.0, ---gnu-style-hidden-option was parsed as GnuStyleHiddenOption, but due to the changes in #2270, 13.0.0 now throws an error: Error: invalid Option flags: '---gnu-style-hidden-option'.

import { Command, Option } from "@commander-js/extra-typings";
const program = new Command();

program
  .addOption(new Option("---gnu-style-hidden-option").hideHelp().default(false))
  .action((opts) => {
    console.log(opts.GnuStyleHiddenOption);
    // 12.1.0: true or false
    // 13.0.0: Error: invalid Option flags: '---gnu-style-hidden-option'

    // N.B. @commander-js/extra-typings correctly infers the type of opts as { GnuStyleHiddenOption: boolean; }
    // (even with @commander-js/extra-typings 13.0.0)
  })
  .parse();

/*
$ node /src/program_a/a.js ---gnu-style-hidden-option
/src/program_a/node_modules/commander/lib/option.js:342
    throw new Error(`invalid Option flags: '${flags}'`);
          ^

Error: invalid Option flags: '---gnu-style-hidden-option'
    at splitOptionFlags (/src/program_a/node_modules/commander/lib/option.js:342:11)
    at new Option (/src/program_a/node_modules/commander/lib/option.js:20:25)
    at file:///src/program_a/a.js:10:16
    at ModuleJob.run (node:internal/modules/esm/module_job:271:25)
    at async onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:547:26)
    at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:116:5)

Node.js v22.12.0
*/

Additional context

In GNU programs, triple-hyphen options are used as hidden debugging options that do not appear in the program --help output. (As far as I know, this is not documented anywhere and seems to be a convention within the GNU project. I think it existed in projects other than coreutils, but I'm not sure.)

• stty ---debug https://github.com/coreutils/coreutils/blob/v9.2/src/stty.c#L495 (since coreutils 9.2)
• tail ---disable-inotify -F a.txt https://github.com/coreutils/coreutils/blob/v9.2/src/tail.c#L240 (since coreutils 7.6)

(I understand this is an unsupported usage, so I think this breaking change is valid. Feel free to close this issue. I just wanted to let you know that this unusual usage existed.)

[shadowspawn]

Thanks for the report and context. The stricter check on what Option flags are supported is picking up a few variations to consider!

Other variations: #2307 #2270 (comment)

[shadowspawn]

The upper case start of the option name GnuStyleHiddenOption is a visible clue that Commander is not expecting this format.

From a code search on GitHub, I think this format is currently very rare, and possibly used in error in these hits rather than on purpose: search

Not currently planning to support this format. (Although I was still interested to hear about it!)