mix-niid-example

var need = require('niid').need;
var mix = require('mixx').mix;

var defaultOptions = Object.freeze({ foo: undefined, 
                                     bar: undefined, 
                                     bam: null, 
                                     baz: null });

function MyThing(options) {
  need(options, 'foo', 'bar'); // `foo` and `bar` are required.
	
  options = mix({}, defaultOptions, options);
	
  mix(this, options);
}

// -- or, in fewer lines --

function MyThing(options) {
  need(options = mix({}, defaultOptions, options), 'foo', 'bar'); // `foo` and `bar` are required.
	
  mix(this, options);
}

/**
 * This results in an object with own-properties 
 * `foo`, `bar`, `bam` and `baz`, with the supplied 
 * values overriding the defaults.
 */
var myThing = new MyThing({ foo: 'foo', bar: 'bar' });

This is niid: https://github.com/benaston/niid/blob/master/src/niid.js
This is mixx: https://github.com/benaston/mixx/blob/master/src/mix.js