trying to set a default on required parm about sywac HOT 2 CLOSED

You have to remember that the object you're exporting represents the command, not its params, which means your sample code is attempting to assign a default value to the command itself, which doesn't make sense.

To more fully configure the params (positionals) for the command, use the params property (array of objects) instead of paramsDesc (array of strings).

Note that, as stated in the docs, paramsDesc is just a shortcut to use when the only thing you need to configure in params would be a description.

paramsDescription or paramsDesc: string or array of strings, shortcut to add description for positional args without defining params

Thus the following are equivalent:

paramsDesc: ['Some description']

params: [{ desc: 'Some description' }]

With that being said, we can fix your sample code by replacing paramsDesc with params and applying the defaultValue to the param configuration object.

Note that it doesn't really make sense to say a param is required when providing a default value, because you want the default value to be used when the argument is not given instead of requiring the user to provide the value.

Here are a couple ways of accomplishing this.

The first one changes the way the positional is declared in the flags DSL string, to remove the implicit requirement by using [] instead of <>:

module.exports = {
  flags: 'pkglist [-p|--pkg] [package]',
  desc: 'Package List.',
  params: [{
    desc: 'Package Name',
    defaultValue: '*'
  }],
  run: a => console.log(`list package ${a.package}`)
}

$ ./issue29.js pkglist -h
Usage: issue29 pkglist [-p|--pkg] [package] [options]

Arguments:
  [-p|--pkg] [package]  Package Name  [string] [default: *]

Global Options:
  -h, --help  Show help                           [boolean]

$ ./issue29.js pkglist
list package *

$ ./issue29.js pkglist x
list package x

The second one keeps the flags DSL the way you have it (using <>) but explicitly marks the param as not required:

module.exports = {
  flags: 'pkglist [-p|--pkg] <package>',
  desc: 'Package List.',
  params: [{
    desc: 'Package Name',
    required: false,
    defaultValue: '*'
  }],
  run: a => console.log(`list package ${a.package}`)
}

$ ./issue29.js pkglist -h
Usage: issue29 pkglist [-p|--pkg] <package> [options]

Arguments:
  [-p|--pkg] <package>  Package Name  [string] [default: *]

Global Options:
  -h, --help  Show help                           [boolean]

$ ./issue29.js pkglist
list package *

$ ./issue29.js pkglist x
list package x

from sywac.

Thanks for clarifying this. Really appreciate the help.

from sywac.