State and Store in frontend codebase - State example - user API

user.ts

const DEFAULT_USER_PICTURE = "https://i.pravatar.cc/300";

export const id = (user: User): string => user.id;
export const displayName = (user: User): string =>
  `${user.firstName} ${user.lastName}`;
export const pictureOrDefault = (user: User): string =>
  user.picture || DEFAULT_USER_PICTURE;

export const createNew = ({
  firstName,
  lastName,
  picture
}: {
  firstName: string;
  lastName: string;
  picture?: string;
}): User => {
  const id = `${Math.round(Math.random() * 1000000)}`;

  return {
    id,
    firstName,
    lastName,
    picture
  };
};