proxy_1.js

const myObject = {};
const loudObject = new Proxy({}, {
  get(target, p) {
    console.log(`Accessing key ${String(p)} at ${(new Error()).stack}`);
    return target[p];
  },

  set(target, p, value) {
    console.log(`Setting key ${String(p)} to ${String(value)} at ${(new Error()).stack}`);
    target[p] = value;
    return true;
  }
});

// "Accessing key hello at Error
//    at Object.get (/Users/user/projects/proxy/index.js:21:62)
//    ..."
loudObject.hello;
// "Setting key hello to woop at Error
//    at Object.get (/Users/user/projects/proxy/index.js:21:62)
//    ..."
loudObject.hello = 'woop';

myObject.hello // 'woop'