Feat: 유저 아이디(nameId) 중복 검사

src/main/java/EatPic/spring/domain/user/controller/UserController.java

@@ -54,5 +54,12 @@ public ResponseEntity<Map<String, Boolean>> checkEmail(@RequestParam String emai
         boolean isDuplicate = userService.isEmailDuplicate(email);
         return ResponseEntity.ok(Map.of("isDuplicate", isDuplicate));
     }
-}
 
+    // 유저 아이디 중복 검사
+    @GetMapping("/check-user-id")
+    @Operation(summary = "유저 아이디 중복 검사")
+    public ResponseEntity<Map<String, Boolean>> checkUserId(@RequestParam String nameId) {
+        boolean isDuplicate = userService.isnameIdDuplicate(nameId);
+        return ResponseEntity.ok(Map.of("isDuplicate", isDuplicate));
+    }
+}

src/main/java/EatPic/spring/domain/user/service/UserService.java

@@ -16,6 +16,7 @@ public interface UserService {
     UserResponseDTO.ProfileDto getMyIcon();
     UserResponseDTO.UserBlockResponseDto blockUser(Long targetUserId);
     boolean isEmailDuplicate(String email);
+    boolean isnameIdDuplicate(String nameId);
 
     // UserQueryService
     UserInfoDTO getUserInfo(HttpServletRequest request);

src/main/java/EatPic/spring/domain/user/service/UserServiceImpl.java

@@ -166,4 +166,9 @@ public UserResponseDTO.UserBlockResponseDto blockUser(Long targetUserId) {
     public boolean isEmailDuplicate(String email){
         return userRepository.existsByEmail(email);
     }
+
+    // 유저 아이디 중복 검사
+    public boolean isnameIdDuplicate(String nameId){
+        return userRepository.existsByNameId(nameId);
+    }
 }