feat - #9 챌린지 생성 api resonse data 형태 변경

src/main/java/sopt/org/HMH/domain/challenge/dto/response/CreatedChallengeResponse.java

@@ -0,0 +1,9 @@
+package sopt.org.HMH.domain.challenge.dto.response;
+
+public record CreatedChallengeResponse(
+        Long challengeId
+) {
+    public static CreatedChallengeResponse of(Long challengeId) {
+        return new CreatedChallengeResponse(challengeId);
+    }
+}

src/main/java/sopt/org/HMH/domain/challenge/service/ChallengeService.java

@@ -6,6 +6,7 @@
 import sopt.org.HMH.domain.app.service.AppService;
 import sopt.org.HMH.domain.challenge.domain.Challenge;
 import sopt.org.HMH.domain.challenge.dto.request.ChallengeRequest;
+import sopt.org.HMH.domain.challenge.dto.response.CreatedChallengeResponse;
 import sopt.org.HMH.domain.challenge.repository.ChallengeRepository;
 import sopt.org.HMH.domain.dayChallenge.service.DayChallengeService;
 import sopt.org.HMH.domain.user.User;
@@ -23,12 +24,12 @@ public class ChallengeService {
     private final AppService appService;
     private final UserService userService;
 
-    public Long addChallenge(Long userId, ChallengeRequest request) {
+    public CreatedChallengeResponse addChallenge(Long userId, ChallengeRequest request) {
         User user = userService.getUserId(userId);
         Challenge challenge = challengeRepository.save(new Challenge(user, request.period()));
         Long dayChallengeId = dayChallengeService.addDayChallenge(challenge, request.goalTime());
-        List<App> apps = appService.addApp(dayChallengeId, request.apps());
+        appService.addApp(dayChallengeId, request.apps());
 
-        return challenge.getId();
+        return CreatedChallengeResponse.of(challenge.getId());
     }
 }