03-reflect.js

const user = {
  firstName: "John",
};

const getHandler = (obj, prop) => {
   // get object attributes
   if(prop in obj) {
     return Reflect.get(obj, prop); // Use object's static method
   }
   
  // Extension - Custom attribute
   if(prop === "nickname") {
     return "Johnny";
   }
   
  // Handle error
   return undefined;
}

const userProxy = new Proxy(user, {
  get: getHandler,
});