Factory.js

function Factory(item) {
  switch (item.type) {
    case 'username':
      return <Username item={item} />;
    case 'password':
      return <Password item={item} />;
    case 'birthday':
      return <Birthday item={item} />;
    case 'gender':
      return <Gender item={item} />;
    default:
      return null;
  }
}