fix: 문서 생성 유니크 제약 충돌을 도메인 오류로 처리

Author: lunarbae628

src/main/java/io/ejangs/docsa/domain/doc/app/DocReader.java

@@ -8,13 +8,17 @@
 import io.ejangs.docsa.global.exception.errorcode.DocErrorCode;
 import io.ejangs.docsa.global.exception.errorcode.UserErrorCode;
 import lombok.RequiredArgsConstructor;
+import org.hibernate.exception.ConstraintViolationException;
+import org.springframework.dao.DataIntegrityViolationException;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
 @Service
 @RequiredArgsConstructor
 public class DocReader {
 
+    private static final String DOC_TITLE_UNIQUE_CONSTRAINT = "uk_user_title";
+
     private final UserRepository userRepository;
     private final DocRepository docRepository;
 
@@ -26,10 +30,17 @@ public User getUserOrThrow(Long userId) {
     }
 
     public Doc create(User user, String title) {
-        Doc doc = docRepository.save(Doc.builder().title(title).user(user).build());
-        docRepository.flush();
-        user.addDocument(doc);
-        return doc;
+        try {
+            Doc doc = docRepository.save(Doc.builder().title(title).user(user).build());
+            docRepository.flush();
+            user.addDocument(doc);
+            return doc;
+        } catch (DataIntegrityViolationException e) {
+            if (isTitleDuplicate(e)) {
+                throw new CustomException(DocErrorCode.TITLE_DUPLICATION);
+            }
+            throw e;
+        }
     }
 
     public void checkTitleDuplicate(Long userId, String title) {
@@ -57,4 +68,13 @@ public void checkByIdAndUserId(Long docId, Long userId) {
         }
     }
 
+    private boolean isTitleDuplicate(DataIntegrityViolationException e) {
+        if (!(e.getCause() instanceof ConstraintViolationException constraintViolationException)) {
+            return false;
+        }
+
+        String constraintName = constraintViolationException.getConstraintName();
+        return constraintName != null && constraintName.endsWith(DOC_TITLE_UNIQUE_CONSTRAINT);
+    }
+
 }

src/main/java/io/ejangs/docsa/domain/doc/app/create/DocCreateOrchestrator.java

@@ -30,6 +30,10 @@ public DocCreateResponse create(String title, User user) {
 
         try {
             return docCreateMySqlTxService.createMySqlPart(title, user, saveContentId);
+        } catch (CustomException e) {
+            log.warn("[SAGA] 문서 생성 실패 -> Mongo 삭제 Outbox 기록.", e);
+            compensateMongo(saveContentId);
+            throw e;
         } catch (Exception e) {
             log.warn("[SAGA] 문서 생성 실패 -> Mongo 삭제 Outbox 기록.", e);
             compensateMongo(saveContentId);

src/test/java/io/ejangs/docsa/domain/doc/app/unit/DocCreateOrchestratorTest.java

@@ -82,4 +82,28 @@ void create_fail_compensateMongo() {
                                 && ids.blockIds().isEmpty())
         );
     }
+
+    @Test
+    @DisplayName("문서 생성 Saga 실패 - MySQL 파트에서 CustomException 발생 시 보상 삭제 후 그대로 전파한다")
+    void create_fail_rethrowCustomException() {
+        User user = org.mockito.Mockito.mock(User.class);
+        SaveContent saved = SaveContent.builder().build();
+        ReflectionTestUtils.setField(saved, "id", "save-1");
+
+        when(saveWriter.createSaveContent()).thenReturn(saved);
+        when(docCreateMySqlTxService.createMySqlPart("doc", user, "save-1"))
+                .thenThrow(new CustomException(DocErrorCode.TITLE_DUPLICATION));
+
+        assertThatThrownBy(() -> orchestrator.create("doc", user))
+                .isInstanceOf(CustomException.class)
+                .hasMessage(DocErrorCode.TITLE_DUPLICATION.getMessage());
+
+        verify(mongoDeleteJobEnqueuer).enqueueDocCreateCompensation(
+                eq("save-1"),
+                argThat(ids ->
+                        ids.saveContentsIds().contains("save-1")
+                                && ids.commitBlockSequenceIds().isEmpty()
+                                && ids.blockIds().isEmpty())
+        );
+    }
 }

src/test/java/io/ejangs/docsa/domain/doc/app/unit/DocReaderUnitTest.java

@@ -0,0 +1,68 @@
+package io.ejangs.docsa.domain.doc.app.unit;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import io.ejangs.docsa.domain.doc.app.DocReader;
+import io.ejangs.docsa.domain.doc.dao.mysql.DocRepository;
+import io.ejangs.docsa.domain.doc.entity.Doc;
+import io.ejangs.docsa.domain.doc.util.DocTestUtils;
+import io.ejangs.docsa.domain.user.dao.mysql.UserRepository;
+import io.ejangs.docsa.domain.user.entity.User;
+import io.ejangs.docsa.global.exception.CustomException;
+import io.ejangs.docsa.global.exception.errorcode.DocErrorCode;
+import org.hibernate.exception.ConstraintViolationException;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.dao.DataIntegrityViolationException;
+
+@ExtendWith(MockitoExtension.class)
+class DocReaderUnitTest {
+
+    @Mock
+    private UserRepository userRepository;
+
+    @Mock
+    private DocRepository docRepository;
+
+    @InjectMocks
+    private DocReader docReader;
+
+    @Test
+    @DisplayName("문서 생성 성공 - 저장 후 flush하고 유저에 문서를 연결한다")
+    void create_success() {
+        User user = DocTestUtils.createUser();
+        Doc doc = Doc.builder().title("doc").user(user).build();
+
+        when(docRepository.save(org.mockito.ArgumentMatchers.any(Doc.class))).thenReturn(doc);
+
+        Doc result = docReader.create(user, "doc");
+
+        assertThat(result).isEqualTo(doc);
+        assertThat(user.getDocs()).contains(doc);
+        verify(docRepository).flush();
+    }
+
+    @Test
+    @DisplayName("문서 생성 실패 - 제목 유니크 제약 충돌이면 TITLE_DUPLICATION을 반환한다")
+    void create_fail_duplicateTitleConstraint() {
+        User user = DocTestUtils.createUser();
+        ConstraintViolationException cause = new ConstraintViolationException(
+                "Duplicate entry '1-doc' for key 'docs.uk_user_title'",
+                null,
+                "docs.uk_user_title");
+
+        when(docRepository.save(org.mockito.ArgumentMatchers.any(Doc.class)))
+                .thenThrow(new DataIntegrityViolationException("could not execute statement", cause));
+
+        assertThatThrownBy(() -> docReader.create(user, "doc"))
+                .isInstanceOf(CustomException.class)
+                .hasMessage(DocErrorCode.TITLE_DUPLICATION.getMessage());
+    }
+}