switch 로 더 깔끔하게 조건문 작성

switch (true) {
  case !isDefined(user):
    throw new Error("User must be defined.");
  case !isString(user.firstName):
    throw new Error("User's first name must be a string");
  case !isValidEmail(user.email):
    throw new Error("User's email address must be a valid email address");
  case !isValidPhoneNumber(user.number):
    throw new Error("User's phone number must be a valid phone number");
  // ...더 많은 유효성 검사들
  default:
    return user;
}

출처: https://ui.toast.com/posts/ko_20210603