shallow_copy.js

function shallowCopy(old) {
 var props = {};
 Object.getOwnPropertyNames(old).forEach(function (name) {
   props[name] = Object.getOwnPropertyDescriptor(old, name);
 });
 return Object.create(Object.getPrototypeOf(old), props);
}

// A very hard and dangerous to copy object
var obj = {
 get foo() { throw new Error("Boom"); },
 set bar(value) { throw new Error("Ouch"); }
}
Object.defineProperty(obj, 'hidden', {value: "Can't see me"});
var clone = shallowCopy(obj);
console.dir(obj);
console.dir(clone);