TypeScript Type Definition Practice

Practical code using TypeScript type definitions and interfaces.

interface User {
  id: string;
  name: string;
  email: string;
  age?: number;
}

type UserRole = "admin" | "user" | "guest";

const createUser = (name: string, role: UserRole): User => {
  return {
    id: crypto.randomUUID(),
    name,
    email: `${name}@example.com`,
  };
};