MOSU-341 refactor: KMC 회원,카카오 중복 회원 동시가입 에러 처리

Author: wlgns12370

src/main/java/life/mosu/mosuserver/application/oauth/OAuthUserPersistenceProcessor.java

@@ -4,6 +4,7 @@
 import life.mosu.mosuserver.domain.user.entity.UserJpaEntity;
 import life.mosu.mosuserver.domain.user.entity.UserRole;
 import life.mosu.mosuserver.domain.user.repository.UserJpaRepository;
+import life.mosu.mosuserver.global.exception.OAuthException;
 import life.mosu.mosuserver.global.processor.StepProcessor;
 import life.mosu.mosuserver.global.util.PhoneNumberUtil;
 import lombok.RequiredArgsConstructor;
@@ -28,9 +29,9 @@ public UserJpaEntity process(final OAuthUserInfo info) {
         return userRepository.findByPhoneNumber(
                         PhoneNumberUtil.formatPhoneNumber(info.phoneNumber()))
                 .map(existingUser -> {
-//                    if (existingUser.isMosuUser()) {
-//                        throw new IllegalArgumentException("이미 모수 회원입니다.");
-//                    }
+                    if (existingUser.isMosuUser()) {
+                        throw new OAuthException("DUPLICATE");
+                    }
                     existingUser.updateOAuthUser(
                             info.gender(),
                             info.name(),

src/main/java/life/mosu/mosuserver/global/exception/OAuthException.java

@@ -0,0 +1,10 @@
+package life.mosu.mosuserver.global.exception;
+
+import org.springframework.security.core.AuthenticationException;
+
+public class OAuthException extends AuthenticationException {
+
+    public OAuthException(String msg) {
+        super(msg);
+    }
+}