Basic Proxy Example

basic_proxy_example.js

const someObject = {};

const someProxy = new Proxy(someObject, {
  get: function (target, property, reciever) {
    if (property.substr(0, 6) === 'happy_') {
      return Reflect.get(target, property.substr(6), reciever);
    }
    return 'sad';
  },
  set: function (target, property, value, reciever) {
    if (property.substr(0, 6) === 'happy_') {
      return Reflect.set(target, property.substr(6), value, reciever);
    }
    return false;
  }
});

someProxy.happy_x = 'happy';
console.log(`someproxy.happy_x = 'happy';`);
console.log('someProxy.x =', someProxy.x);
console.log('someObject.x =', someObject.x);
console.log('someProxy.happy_x =', someProxy.happy_x);
console.log('someObject.happy_x =', someObject.happy_x);

output.txt

someproxy.happy_x = 'happy';
someProxy.x = sad
someObject.x = happy
someProxy.happy_x = happy
someObject.happy_x = undefined