Feature request - looking for enum

[ORESoftware]

Here are all options for an argument (as listed in docs):

{
    names: ['file', 'f'],       // Required (one of `names` or `name`).
    type: 'string',             // Required.
    completionType: 'filename',
    env: 'MYTOOL_FILE',
    help: 'Config file to load before running "mytool"',
    helpArg: 'PATH',
    helpWrap: false,
    default: path.resolve(process.env.HOME, '.mytoolrc')
}

I am looking for an enum option, so I can use it like so:

{
  names: ['signal','s']
  type: 'string',
  enum: ['SIGINT', 'SIGTERM', 'SIGKILL']     // <<<<<<<< here
}

I can handle that in my code, but it would be nice if dashdash could do that!

thanks

[ORESoftware]

bump @trentm

[karfau]

This should be easy to add when needed by adding a custom type:
https://github.com/trentm/node-dashdash#custom-option-types

There is even an example how to do this:
https://github.com/trentm/node-dashdash/blob/master/examples/custom-option-fruit.js

So the library is extensible enough, to allow this behavior.
It doesn't really need to be added as part of it.