public class RateDiscountPolicy implements DiscountPolicy{
private int discountPercent = 10; // 10% 할인
@Override
public int discount(Member member, int price) {
if (member.getGrade() == Grade.VIP){
return price * discountPercent / 100;
} else {
return 0;
}
}
}
class RateDiscountPolicyTest {
RateDiscountPolicy discountPolicy = new RateDiscountPolicy();
@Test
@DisplayName("VIP는 10% 할인이 적용되어야 한다")
void vip_o(){
// given
Member member = new Member(1L, "memberVip", Grade.VIP);
// when
int discount = discountPolicy.discount(member, 10000);
// then
assertThat(discount).isEqualTo(1000);
}
@Test
@DisplayName("VIP가 아니면 할인이 적용되지 않아야 한다")
void vip_x(){
// given
Member member = new Member(2L, "memberBASIC", Grade.BASIC);
// when
int discount = discountPolicy.discount(member, 10000);
// then
assertThat(discount).isEqualTo(0);
}
}
public class OrderServiceImpl implements OrderService{
private final MemberRepository memberRepository = new MemoryMemberRepository();
// private final DiscountPolicy discountPolicy = new FixDiscountPolicy();
// private final DiscountPolicy discountPolicy = new RateDiscountPolicy();
private DiscountPolicy discountPolicy;
@Override
public Order createOrder(Long memberId, String itemName, int itemPrice) {
Member member = memberRepository.findById(memberId);
int discountPrice = discountPolicy.discount(member, itemPrice);
return new Order(memberId, itemName, itemPrice, discountPrice);
}
}
=> 누군가가 클라이언트인 OrderServiceImpl 에 DiscountPolicy 의 구현 객체를 대신 생성하고 주입해주어야 한다.