Commander.js: option() default value doesn't work with parseInt

[DeoLeung]

  commander.option('-I --increment [value]', 'The interval increment', parseInt)
  commander.increment // works if '-I 2'
  commander.option('-I --increment [value]', 'The interval increment', parseInt, 1)
  commander.increment // gives NaN if '-I 2'

Seems like a bug or do I get it wrong?

[DeoLeung]

  commander.option('-I --increment [value]', 'The interval increment', str => parseInt(str), 1)

this works though

[bfricka]

Did you try debugging it? My first guess would be that it's passing two params (input and default), which ends up calling parseInt with an invalid radix (e.g. parseInt(2, 1) // NaN)

[bfricka]

BTW this is the behavior across options which allows you to do things like collections:

commander.option('-f, --foo <val>', 'Add values to foo', collect, []);
function collect(val, collection) {
  collection.push(val);
  return collection;
}

Which can be invoked: program --foo=hi --foo=bye and yields ['hi', 'bye']

[DeoLeung]

@bfricka yes you made a right guess 👍
would be better to improve the doc :)