Hotfix/#54

src/main/java/com/moplus/moplus_server/domain/problem/controller/ProblemController.java

@@ -3,6 +3,7 @@
 import com.moplus.moplus_server.domain.problem.dto.request.ProblemPostRequest;
 import com.moplus.moplus_server.domain.problem.dto.request.ProblemUpdateRequest;
 import com.moplus.moplus_server.domain.problem.dto.response.ProblemGetResponse;
+import com.moplus.moplus_server.domain.problem.dto.response.ProblemPostResponse;
 import com.moplus.moplus_server.domain.problem.service.ChildProblemService;
 import com.moplus.moplus_server.domain.problem.service.ProblemDeleteService;
 import com.moplus.moplus_server.domain.problem.service.ProblemGetService;
@@ -45,10 +46,10 @@ public ResponseEntity<ProblemGetResponse> getProblem(
 
     @PostMapping("")
     @Operation(summary = "문항 생성", description = "문제를 생성합니다. 기출/변형 문제는 모든 값이 필수이며 창작 문제는 문항 타입만 필수 입니다.")
-    public ResponseEntity<IdResponse> createProblem(
+    public ResponseEntity<ProblemPostResponse> createProblem(
             @Valid @RequestBody ProblemPostRequest request
     ) {
-        return ResponseEntity.ok(new IdResponse(problemSaveService.createProblem(request)));
+        return ResponseEntity.ok(problemSaveService.createProblem(request));
     }
 
     @PutMapping("/{id}")

src/main/java/com/moplus/moplus_server/domain/problem/domain/problem/Difficulty.java

@@ -17,14 +17,14 @@ public class Difficulty {
     private Integer difficulty;
 
     public Difficulty(Integer difficulty) {
-        if (difficulty == null) {
-            return;
-        }
         validate(difficulty);
         this.difficulty = difficulty;
     }
 
-    private void validate(int difficulty) {
+    private void validate(Integer difficulty) {
+        if (difficulty == null) {
+            return;
+        }
         if (difficulty < 1 || difficulty > 10) {
             throw new InvalidValueException(ErrorCode.INVALID_DIFFICULTY);
         }

src/main/java/com/moplus/moplus_server/domain/problem/domain/problem/Problem.java

@@ -134,7 +134,7 @@ public void updateChildProblem(List<ChildProblem> inputChildProblems) {
         if (isConfirmed && this.childProblems.size() != inputChildProblems.size()) {
             throw new InvalidValueException(ErrorCode.INVALID_CHILD_PROBLEM_SIZE);
         }
-        
+
         for (int i = 0; i < inputChildProblems.size(); i++) {
             this.childProblems.get(i).update(inputChildProblems.get(i));
         }
@@ -160,10 +160,10 @@ public boolean isValid() {
     }
 
     public String getTitle() {
-        return title.getTitle();
+        return title != null ? title.getTitle() : "제목 없음";
     }
 
     public Integer getDifficulty() {
-        return difficulty.getDifficulty();
+        return difficulty != null ? difficulty.getDifficulty() : null;
     }
 }

src/main/java/com/moplus/moplus_server/domain/problem/dto/response/ProblemPostResponse.java

@@ -0,0 +1,15 @@
+package com.moplus.moplus_server.domain.problem.dto.response;
+
+import com.moplus.moplus_server.domain.problem.domain.problem.Problem;
+import jakarta.validation.constraints.NotNull;
+
+public record ProblemPostResponse(
+        @NotNull(message = "문항 ID는 필수입니다")
+        Long id,
+        @NotNull(message = "문항 custom ID는 필수입니다")
+        Long problemCustomId
+) {
+    public static ProblemPostResponse of(Problem problem) {
+        return new ProblemPostResponse(problem.getId(), problem.getPracticeTestId());
+    }
+}

src/main/java/com/moplus/moplus_server/domain/problem/service/ProblemSaveService.java

@@ -5,6 +5,7 @@
 import com.moplus.moplus_server.domain.problem.domain.problem.ProblemAdminIdService;
 import com.moplus.moplus_server.domain.problem.domain.problem.ProblemCustomId;
 import com.moplus.moplus_server.domain.problem.dto.request.ProblemPostRequest;
+import com.moplus.moplus_server.domain.problem.dto.response.ProblemPostResponse;
 import com.moplus.moplus_server.domain.problem.repository.PracticeTestTagRepository;
 import com.moplus.moplus_server.domain.problem.repository.ProblemRepository;
 import com.moplus.moplus_server.domain.problem.service.mapper.ProblemMapper;
@@ -22,13 +23,12 @@ public class ProblemSaveService {
     private final ProblemMapper problemMapper;
 
     @Transactional
-    public Long createProblem(ProblemPostRequest request) {
+    public ProblemPostResponse createProblem(ProblemPostRequest request) {
         PracticeTestTag practiceTestTag = practiceTestRepository.findByIdElseThrow(request.practiceTestId());
         ProblemCustomId problemCustomId = problemAdminIdService.nextId(request.number(), practiceTestTag,
                 request.problemType());
 
         Problem problem = problemMapper.from(request, problemCustomId, practiceTestTag);
-
-        return problemRepository.save(problem).getId();
+        return ProblemPostResponse.of(problemRepository.save(problem));
     }
 }

src/test/java/com/moplus/moplus_server/domain/problem/service/ProblemSaveServiceTest.java

@@ -6,6 +6,7 @@
 import com.moplus.moplus_server.domain.problem.domain.problem.Problem;
 import com.moplus.moplus_server.domain.problem.domain.problem.ProblemType;
 import com.moplus.moplus_server.domain.problem.dto.request.ProblemPostRequest;
+import com.moplus.moplus_server.domain.problem.dto.response.ProblemPostResponse;
 import com.moplus.moplus_server.domain.problem.repository.ProblemRepository;
 import com.moplus.moplus_server.global.error.exception.NotFoundException;
 import org.junit.jupiter.api.BeforeEach;
@@ -46,12 +47,12 @@ class 문항생성 {
         @Test
         void 성공() {
             // when
-            Long createdProblemId = problemSaveService.createProblem(problemPostRequest);
+            ProblemPostResponse problemResponse = problemSaveService.createProblem(problemPostRequest);
 
             // then
-            assertThat(createdProblemId).isNotNull();
+            assertThat(problemResponse).isNotNull();
 
-            Problem savedProblem = problemRepository.findByIdElseThrow(createdProblemId);
+            Problem savedProblem = problemRepository.findByIdElseThrow(problemResponse.id());
             assertThat(savedProblem).isNotNull();
             assertThat(savedProblem.getProblemType()).isEqualTo(ProblemType.GICHUL_PROBLEM);
         }