How to reference functions in fittingDef

[dragos-cojocari]

I cannot figure how to include functions in the configuration for fittings. Using CORS as example I'd like to provide the origin as a function and the only way to do this now is to duplicate the cors fitting in my project's fittings folder like this:

'use strict';

const debug = require('debug')('swagger:cors');
const CORS = require('cors');

// config options: https://www.npmjs.com/package/cors
const options = {
  origin: function() {
    ....
  }
};

module.exports = function create(fittingDef, bagpipes) {
  debug('config: %j', fittingDef);
  const middleware = CORS(Object.assign({}, fittingDef, options));

  return function cors(context, cb) {
    debug('exec');
    middleware(context.request, context.response, cb);
  };
};

What I'd love to be able to just specify the function in Swagger's config.xml :

  bagpipes:
   ...
    cors:
      name: cors
      origin: <Some way to reference the function>

Thank you.