Cocktail.js

//     Cocktail.js 0.1.0

//     (c) 2012 Onsi Fakhouri
//     Cocktail.js may be freely distributed under the MIT license.
//     http://github.com/onsi/cocktail

(function() {
  var originalExtend = Backbone.Model.extend;

  var mixin = function(klass) {
    var mixins = _.flatten(_.rest(arguments));

    var collisions = {};

    _(mixins).each(function(mixin) {
      _(mixin).each(function(value, key) {
        if (key == 'events') {
          klass.prototype.events = _.extend({}, klass.prototype.events || {}, value);
        } else if (_.isFunction(value)) {
          if (klass.prototype[key]) {
            collisions[key] = collisions[key] || [klass.prototype[key]];
            collisions[key].push(value);
          }
          klass.prototype[key] = value;
        }
      });
    });

    _(collisions).each(function(propertyValues, propertyName) {
      klass.prototype[propertyName] = function() {
        var that = this, args = arguments, returnValue = undefined;

        _(propertyValues).each(function(value) {
          var returnedValue = _.isFunction(value) ? value.apply(that, args) : value;
          returnValue = (returnedValue === undefined ? returnValue : returnedValue);
        });

        return returnValue;
      }
    });
  }

  var extend = function(protoProps, classProps) {
    var klass = originalExtend.call(this, protoProps, classProps);
    var mixins = klass.prototype.mixins;

    if (mixins && klass.prototype.hasOwnProperty('mixins')) {
      mixin(klass, mixins);
    }

    return klass;
  }
  Backbone.Model.mixin = Backbone.Collection.mixin = Backbone.Router.mixin = Backbone.View.mixin = function() {
    mixin(this, _.toArray(arguments));
  };
  Backbone.Model.extend = Backbone.Collection.extend = Backbone.Router.extend = Backbone.View.extend = extend;
})();