Nested Object Protection Wrapper

example.js

var object = {
    "value": 1,
    "anotherValue": 2,
    "nested": {
        "value": 3
    }
};

object.value
// => 1

var object2 = protectedWrapper(object);

object2.get('value')
// => 1

object2.get('nested.value')
// => 3

protected-object-wrapper.js

function protectedWrapper(object) {
    return {
        get: function(key) {
            if (typeof key === 'undefined' || typeof key === 'null') {
                return;
            }
            var obj = extend({}, object);
            key.split(/[\[\]\.]/g).filter(Boolean).forEach(function(key) {
                obj = obj ? obj[key] : null;
            });
            return typeof obj == 'object' ? protectedWrapper(obj) : obj;
        }
    }
}

function extend() {
    var result = arguments[0];
    for(var i = 1; i < arguments.length; i++) {
        for(var key in arguments[i]) {
            result[key] = arguments[i][key];
        }
    }
    return result;
}