javascript: composition

composition.js

const capitalize = str => (
  str.replace(/\w\S*/g, txt =>
    txt.charAt(0)
       .toUpperCase() + txt.substr(1).toLowerCase())
);

const users = [{
  id: 1, name: 'joalbert', surname: 'gonzález'
}];

//const getFullName = _users => {
//  const first = _users[0];
//  const capitalized = {
//    name: capitalize(first.name),
//    surname: capitalize(first.surname)
//  }
//  return `${capitalized.name} ${capitalized.surname}`;
//}

const compose = (...fns) => x => fns.reduceRight((y, f) => f(y), x);

const head = _users => _users[0];
const capitalized = ({name, surname}) => ({
  name: capitalize(name),
  surname: capitalize(surname)
});
const print = ({name, surname}) => `${name} ${surname}`;

const getFullName_v1 = _users => print(capitalized(head(_users)));
//const getFullName_v2 = _users => compose(print, capitalized, head)(_users);
const getFullName_v2 = compose(print, capitalized, head);

console.log(getFullName_v1(users));
console.log(getFullName_v2(users));