AppConfig의 @Bean 메서드의 이름을 아무렇게나 지으면 안되나요?

@Configuration
public class AppConfig {
    @Bean
    public MemoryMemberRepository memoryRepository() {
        return new MemoryMemberRepository();
    }
    @Bean
    public RateDiscountPolicy discountPolicy() {
        return new RateDiscountPolicy();
    }
    @Bean
    public MemberService memberService(){
        return new MemberServiceImpl(memoryRepository());
    }
    @Bean
    public OrderService orderService(){
//        return null;
        return new OrderServiceImpl(memoryRepository(), discountPolicy());
    }

}

저는 지금까지 위의 코드처럼 MemoryMemberRepository 빈 객체를 생성하는 메서드의 이름을 memberRepository가 아니라 memoryRepository로 이름지어주고 진행해왔습니다.

그러다가 7.의존관계 자동 주입 챕터에서 test 폴더를 전부 테스트할 때

CoreApplicationTests에서 동일한 타입에 여러 Bean이 생성되었다는 오류 메시지를 받았습니다.

Parameter 0 of constructor in hello.core.member.MemberServiceImpl required a single bean, but 2 were found:

- memoryMemberRepository: defined in file [C:\Users\***\***\coding\source_code\Spring\inflearn2\out\production\classes\hello\core\member\MemoryMemberRepository.class]

- memoryRepository: defined by method 'memoryRepository' in class path resource [hello/core/AppConfig.class]

///

Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'hello.core.member.MemberRepository' available: expected single matching bean but found 2: memoryMemberRepository,memoryRepository

해결하려는 과정에서 강의노트에 메서드 이름이 memberRepository였다는걸 알게됐고 이걸로 이름을 고쳐주고 다시 테스트하니까 정상적으로 테스트가 완료됐습니다.

메서드 이름만 바꿔준 것만으로 NoUniqueBean 오류가 해결된 이유가 궁금해졌습니다.

이것저것 코드를 건드렸는데 @Component 코드들을 아래에 붙이겠습니다. 감사합니다.

@Component
public class MemberServiceImpl implements MemberService{
    private MemberRepository store;

    @Autowired
    public MemberServiceImpl(MemberRepository memberRepository){
        this.store = memberRepository;
    }

    @Override
    public void register(Member newMember) {
        store.save(newMember);
    }

    @Override
    public Member search(Long memberId) {
        return store.findById(memberId);
    }
}

@Component
public class MemoryMemberRepository implements MemberRepository{
    private static Map<Long, Member> store = new HashMap<>();

    @Override
    public void save(Member member) {
        store.put(member.getId(), member);
    }

    @Override
    public Member findById(Long memberId) {
        return store.get(memberId);
    }
}

@Component
public class OrderServiceImpl implements OrderService {
    private MemberRepository memberRepository;
    private DiscountPolicy discountPolicy;

    @Autowired
    public OrderServiceImpl(MemberRepository memberRepository, DiscountPolicy discountPolicy) {
        System.out.println("Constructor DI");
        this.memberRepository = memberRepository;
        this.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);
    }
}

@Component
public class RateDiscountPolicy implements DiscountPolicy{
    private static final double DISCOUNT_RATE = 0.1;
    @Override
    public int discount(Member member, int price) {

        if(member.getGrade() == Grade.VIP)
            return (int) (price * DISCOUNT_RATE);
        else
            return 0;
    }
}