I want to implement an interface that collects all options after a positional option. The options are not known ahead of time.

Usage would look something like:

script.js --scriptOption script2 positionalArgToScript2 --optionForScript2

If a real life example helps, this is similar to how docker run works:

docker run [OPTIONS] IMAGE[:TAG|@DIGEST] [COMMAND] [ARG...]

allowing you to run something like this:

docker run --rm alpine echo -n hi

Crucially, in this example, -n hi is passed to echo and is not treated as an option to docker run.

Here's how you might try to do that in yargs:

const yargs = require('yargs');
const { hideBin } = require('yargs/helpers');

const argv = yargs(hideBin(process.argv))
    .command('$0 <cmd> [args...]')
    .argv;

But when run like so

test.js echo -n hi there

argv ends up as

{ _: [],
  n: 'hi',
  '$0': 'test.js',
  cmd: 'echo',
  args: [ 'there' ] }

Notice how args is [ 'there' ] instead of [ '-n', 'hi', 'there' ].

Workarounds

Force callers to put -- after your options. If you only had a default command, then you could just drop it:

yargs(hideBin(process.argv))
    // .command('$0 <cmd> [args...]')
    .argv;

Then you'd call your script with test.js -- echo -n hi there and get the args from _.

See yargs/yargs-parser#145 for a related discussion around quoting arguments containing dashes.