const target = { name: 'Alice' };

const handler = {
  get(obj, prop) {
    return prop in obj ? obj[prop].toUpperCase() : 'NOT_FOUND';
  },
  set(obj, prop, value) {
    if (typeof value !== 'string') {
      return false;
    }
    obj[prop] = value.trim();
    return true;
  }
};

const proxy = new Proxy(target, handler);
proxy.name = '  Bob  ';
proxy.age = 30;

console.log(`${proxy.name}-${proxy.age}-${proxy.job}`);