08-user-ts-cast.ts

interface User {
  firstName: string;
  middleName?: string;
  lastName: string;
  email: string;
  balance: number;
  currency: string;
  locale: string;
}

interface UserProxy extends User {
  fullName: string; // new property
  balance: string; // redefined propery
}

const handleGet = (obj: User, prop: string | symbol) => {
 /* ... */
};


export const createUserDataProxy = (user: User): UserProxy => {
  const proxy = new Proxy(user, {
    get: handleGet,
  }) as unknown as UserProxy;

  return proxy;
};