index.js

const obj = {};
const p = new Proxy(obj, {
    get: (target, name) => {
    console.log(`(get) target : ${JSON.stringify(target)}, name: ${name}`);
    return target[name];
  },
  set: (target, name, value) => {
    console.log(`(set) target : ${JSON.stringify(target)}, name: ${name}`);
    target[name] = value;
  }
});

p.a = "hello";
p.a
// -> hello