// Return the trap result function setFoo(x,y) { this.foo = x + y; } var handler = { construct: function (target, args) { return { foo : args[0] * args[1]}; } } for (let proxy of [new Proxy(setFoo, handler), Proxy.revocable(setFoo, handler).proxy]) { var obj1 = new proxy(2, 3); assertEq(obj1.foo, 6); obj1.bar = proxy; var obj2 = new obj1.bar(2, 3); assertEq(obj2.foo, 6); }