cow

copy on write deep, cyclic js objects

Cow

Cow provides a completely transparent copy on write proxy to deep, cyclic js objects.

$ npm install cow

Also note that the copy correctly preserves the objects inheritance and hidden/accessor properties.

function Test() { this.child = {}; }
var obj = new Test(); // provided a normal js object, which 
obj.child.obj = obj; // can contain cycles 
obj.child2 = obj.child // and references 
 
var cow = new Cow(obj);
var proxy = cow.proxy;
 
// the proxy has all the properties of obj! 
proxy.child.obj === proxy;
proxy.child2 === proxy.child;
 
// we can write new properties 
proxy.child3 = proxy; // even create new cycles! 
 
// convert the proxy back to plain object: 
var finished = cow.finish();
finished.child3 === finished;
finished.child.obj === finished;
finished.child === finished.child2;
 
// and it has left the original object untouched: 
obj !== finished;
obj.child !== finished.child;

LGPLv3