composesugar.js

var util = require('util');

exports.compose = function(object, trait) {
	var dynamicConstructor = function(args) {
		return object.apply(this, args);
	};

	dynamicConstructor.prototype = object.prototype;

	var constructor = function() {
		this._child = new dynamicConstructor(arguments);

		trait.apply(this, arguments);
	};

	for (var key in object.prototype) {
		var value = object.prototype[key];

		if (typeof value == 'function') {
			constructor.prototype[key] = function() {
				// Get the instance value in case something monkey patched it
				return this._child[key].apply(this._child, arguments);
			};
		} else {
			Object.defineProperty(constructor.prototype, key, {
				configurable: true,
				enumerable: true,
				writable: true,
				get: function() {
					return this._child[key];
				},
				set: function(value) {
					this._child[key] = value;
				}
			});
		}
	}

	for (var key in trait.prototype) {
		var descriptor = Object.getOwnPropertyDescriptor(trait.prototype, key);

		if (descriptor) {
			Object.defineProperty(constructor.prototype, key, descriptor);
		} else {
			constructor.prototype = trait.prototype[key];
		}
	}

	return constructor;
};