gistfile1.txt

/*
 * This is a JavaScript Scratchpad.
 *
 * Enter some JavaScript, then Right Click or choose from the Execute Menu:
 * 1. Run to evaluate the selected text,
 * 2. Inspect to bring up an Object Inspector on the result, or,
 * 3. Display to insert the result in a comment after the selection.
 */

function wrap(val) {
    var type = typeof val;
    if (type == 'string' || type == 'number' || type == 'boolean'
        || val == undefined || val === null)
    {
        return val;
    }

    function getOwnPropertyDescriptor(name) {
        var desc = Object.getOwnPropertyDescriptor(val, name);    
        if (desc === undefined)
            return desc;
        if ('value' in desc) {
            desc.value = wrap(desc.value);
            desc.writable = false;
        } else {
            desc.setter = null;
            desc.getter = wrap(desc.getter);
        }
        return desc;
    }

    var handler = {
        getOwnPropertyDescriptor: getOwnPropertyDescriptor,
        getPropertyDescriptor: getOwnPropertyDescriptor
    };

    return Proxy.create(handler, null);
}


"use strict";
var p = wrap({x:1});
p.x
p.x = 2;


var s = new Components.utils.Sandbox("http://www.example.com/",
    {sandboxPrototype: wrap(this)});

var x;

var q;
Object.defineProperty(this, "foo", {set: function (value) { q = value; }});

s.evalInSandbox("x = 2;");
Components.utils.evalInSandbox("x=2", s);
x;
Components.utils.evalInSandbox("x", s);
s.x;



s.eval("foo = 3;");

q;


s.eval("Object.getPrototypeOf(this).xyz = 5;")
xyz;