Wrong help behavior for commands with proxy options

[lordofthelake]

This is a toy implementation of a command that is supposed to execute a sub-command for each package in a monorepo. It takes as arguments the sub-command to run in the context of each package, and an optional flag to exclude certain packages from the process.

export class WorkspaceEachCommand extends Command<BaseContext> {
  static paths = [["each"]];

  exclusions = Option.Array("-x,--exclude");
  subcommand = Option.Proxy();

  async execute(): Promise<number | void> {
    const { stdout } = this.context;
    const { exclusions, subcommand } = this;
    stdout.write(JSON.stringify({ exclusions, subcommand }));
  }

The usage (after taking into account #85, having the flags preceding the command) would be:

$ mytool -x ugly-package -x other-package-i-dont-like each do-something-interesting
{"exclusions":["ugly-package","other-package-i-dont-like"],"subcommand":["do-something-interesting"]}

This works correctly, or at least according to the expectations lined out in #85. If I try to get help for this command, though, things go wrong:

$ mytool each --help
{"subcommand":["--help"]}

Inverting the command and the flag also goes wrong – for different reasons:

$ mytool --help each
Unknown Syntax Error: Extraneous positional argument ("each").

$ mytool -h

If I type a wrong command, the help text suggests the wrong syntax, with the flags after the command. Given how the usage function is structured, I think it would show up also in the help for the single command, if it could be accessed.

$ mytool wrong 
Unknown Syntax Error: Command not found; did you mean one of:

  0. mytool -h
  1. mytool -v
  2. mytool each [-x,--exclude #0] ...

While running wrong

Any suggestions for that?

[winniehell]

This is my workaround:

export class RunCommand extends Command {
  static name = 'run';
  static paths = [[RunCommand.name]];

  args = Option.Proxy();

  async execute() {
    // help command is consumed by Option.Proxy
    // see https://github.com/arcanis/clipanion/issues/88
    const helpFlags = new Set(Builtins.HelpCommand.paths.map(path => path[0]));
    const helpFlagIndex = this.args.findIndex(flag => helpFlags.has(flag));
    if (-1 < helpFlagIndex && helpFlagIndex < [...this.args, '--'].indexOf('--')) {
      this.context.stdout.write(this.cli.usage(RunCommand, {detailed: true}));
      return;
    }

    // …
  }
}

This way … run --help shows the clipanion help while … run -- --help proxies the help flag.