An use of spread operator in JavaScript

spread.js

const user = {
  name: 'Lucas',
  lastName: 'Hiago'
};

function getUserWithFullName(user) {
  return {
    ...user, //spead operator
    fullName: `${user.name} ${user.lastName}`
  }
}

const userWithFullName = getUserWithFullName(user);

console.log(userWithFullName, user);

// output: Lucas Hiago