이메일 중복 확인 기능 구현

src/main/java/sixgaezzang/sidepeek/skill/serivce/SkillService.java

@@ -1,6 +1,6 @@
 package sixgaezzang.sidepeek.skill.serivce;
 
-import static sixgaezzang.sidepeek.common.ValidationUtils.validateMaxLength;
+import static sixgaezzang.sidepeek.common.util.ValidationUtils.validateMaxLength;
 
 import java.util.Objects;
 import lombok.RequiredArgsConstructor;
@@ -24,7 +24,7 @@ public SkillSearchResponse searchByName(String keyword) {
         }
 
         validateMaxLength(keyword, KEYWORD_MAX_LENGTH,
-                "최대 " + KEYWORD_MAX_LENGTH + "자의 키워드로 검색할 수 있습니다.");
+            "최대 " + KEYWORD_MAX_LENGTH + "자의 키워드로 검색할 수 있습니다.");
 
         return SkillSearchResponse.from(skillRepository.findAllByNameContaining(keyword));
     }

src/main/java/sixgaezzang/sidepeek/users/controller/UserController.java

@@ -9,6 +9,7 @@
 import jakarta.validation.constraints.Size;
 import java.net.URI;
 import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
@@ -18,14 +19,17 @@
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
 import sixgaezzang.sidepeek.users.domain.Provider;
-import sixgaezzang.sidepeek.users.dto.SignUpRequest;
-import sixgaezzang.sidepeek.users.dto.UserSearchResponse;
+import sixgaezzang.sidepeek.users.dto.request.CheckEmailRequest;
+import sixgaezzang.sidepeek.users.dto.request.SignUpRequest;
+import sixgaezzang.sidepeek.users.dto.response.CheckDuplicateResponse;
+import sixgaezzang.sidepeek.users.dto.response.UserSearchResponse;
 import sixgaezzang.sidepeek.users.service.UserService;
 
 @RestController
 @RequestMapping("/users")
 @Tag(name = "User", description = "User API")
 @RequiredArgsConstructor
+@Slf4j
 public class UserController {
 
     private final UserService userService;
@@ -58,4 +62,17 @@ public ResponseEntity<UserSearchResponse> searchByNickname(
             .body(userService.searchByNickname(keyword));
     }
 
+    @PostMapping("/email/check")
+    @Operation(summary = "이메일 중복 확인")
+    @ApiResponse(responseCode = "200", description = "이메일 중복 확인 성공")
+    @Parameter(name = "email", description = "이메일", example = "[email protected]")
+    public ResponseEntity<CheckDuplicateResponse> checkEmailDuplicate(
+        @RequestBody @Valid CheckEmailRequest request
+    ) {
+        CheckDuplicateResponse response = userService.checkEmailDuplicate(request.email());
+
+        return ResponseEntity.ok()
+            .body(response);
+    }
+
 }

src/main/java/sixgaezzang/sidepeek/users/dto/request/CheckEmailRequest.java

@@ -0,0 +1,10 @@
+package sixgaezzang.sidepeek.users.dto.request;
+
+import jakarta.validation.constraints.Email;
+
+public record CheckEmailRequest(
+    @Email
+    String email
+) {
+
+}

src/main/java/sixgaezzang/sidepeek/users/dto/SignUpRequest.java → src/main/java/sixgaezzang/sidepeek/users/dto/request/SignUpRequest.java

@@ -1,4 +1,4 @@
-package sixgaezzang.sidepeek.users.dto;
+package sixgaezzang.sidepeek.users.dto.request;
 
 import jakarta.validation.constraints.Email;
 import jakarta.validation.constraints.NotBlank;

src/main/java/sixgaezzang/sidepeek/users/dto/response/CheckDuplicateResponse.java

@@ -0,0 +1,7 @@
+package sixgaezzang.sidepeek.users.dto.response;
+
+public record CheckDuplicateResponse(
+    boolean isDuplicated
+) {
+
+}

src/main/java/sixgaezzang/sidepeek/users/dto/UserSearchResponse.java → src/main/java/sixgaezzang/sidepeek/users/dto/response/UserSearchResponse.java

@@ -1,4 +1,4 @@
-package sixgaezzang.sidepeek.users.dto;
+package sixgaezzang.sidepeek.users.dto.response;
 
 import java.util.List;
 import sixgaezzang.sidepeek.users.domain.User;

src/main/java/sixgaezzang/sidepeek/users/dto/UserSummaryResponse.java → src/main/java/sixgaezzang/sidepeek/users/dto/response/UserSummaryResponse.java

@@ -1,4 +1,4 @@
-package sixgaezzang.sidepeek.users.dto;
+package sixgaezzang.sidepeek.users.dto.response;
 
 import lombok.Builder;
 import sixgaezzang.sidepeek.users.domain.User;

src/main/java/sixgaezzang/sidepeek/users/service/UserService.java

@@ -1,6 +1,7 @@
 package sixgaezzang.sidepeek.users.service;
 
-import static sixgaezzang.sidepeek.common.ValidationUtils.validateMaxLength;
+import static sixgaezzang.sidepeek.common.util.ValidationUtils.validateEmail;
+import static sixgaezzang.sidepeek.common.util.ValidationUtils.validateMaxLength;
 
 import jakarta.persistence.EntityExistsException;
 import java.util.Objects;
@@ -11,8 +12,9 @@
 import sixgaezzang.sidepeek.users.domain.Password;
 import sixgaezzang.sidepeek.users.domain.Provider;
 import sixgaezzang.sidepeek.users.domain.User;
-import sixgaezzang.sidepeek.users.dto.SignUpRequest;
-import sixgaezzang.sidepeek.users.dto.UserSearchResponse;
+import sixgaezzang.sidepeek.users.dto.request.SignUpRequest;
+import sixgaezzang.sidepeek.users.dto.response.CheckDuplicateResponse;
+import sixgaezzang.sidepeek.users.dto.response.UserSearchResponse;
 import sixgaezzang.sidepeek.users.repository.UserRepository;
 
 @Service
@@ -52,7 +54,7 @@ public UserSearchResponse searchByNickname(String keyword) {
         }
 
         validateMaxLength(keyword, KEYWORD_MAX_LENGTH,
-                "최대 " + KEYWORD_MAX_LENGTH + "자의 키워드로 검색할 수 있습니다.");
+            "최대 " + KEYWORD_MAX_LENGTH + "자의 키워드로 검색할 수 있습니다.");
 
         return UserSearchResponse.from(userRepository.findAllByNicknameContaining(keyword));
     }
@@ -69,4 +71,10 @@ private void verifyUniqueEmail(SignUpRequest request) {
         }
     }
 
+    public CheckDuplicateResponse checkEmailDuplicate(String email) {
+        validateEmail(email, "이메일 형식이 올바르지 않습니다.");
+
+        boolean isExists = userRepository.existsByEmail(email);
+        return new CheckDuplicateResponse(isExists);
+    }
 }

src/test/java/sixgaezzang/sidepeek/users/service/UserServiceTest.java

@@ -19,7 +19,8 @@
 import sixgaezzang.sidepeek.users.domain.Password;
 import sixgaezzang.sidepeek.users.domain.Provider;
 import sixgaezzang.sidepeek.users.domain.User;
-import sixgaezzang.sidepeek.users.dto.SignUpRequest;
+import sixgaezzang.sidepeek.users.dto.request.SignUpRequest;
+import sixgaezzang.sidepeek.users.dto.response.CheckDuplicateResponse;
 import sixgaezzang.sidepeek.users.repository.UserRepository;
 
 @SpringBootTest
@@ -133,6 +134,48 @@ class 회원가입_테스트 {
         }
     }
 
+    @Nested
+    class 이메일_중복_확인_테스트 {
+
+        @Test
+        void 이메일이_중복되지_않은_경우_중복_확인에_성공한다() {
+            // when
+            CheckDuplicateResponse response = userService.checkEmailDuplicate(email);
+
+            // then
+            assertThat(response.isDuplicated()).isFalse();
+        }
+
+        @Test
+        void 이메일이_중복된_경우_중복_확인에_성공한다() {
+            // given
+            String duplicatedEmail = email;
+            User user = createUser(duplicatedEmail, password, nickname);
+            userRepository.save(user);
+
+            // when
+            CheckDuplicateResponse response = userService.checkEmailDuplicate(duplicatedEmail);
+
+            // then
+            assertThat(response.isDuplicated()).isTrue();
+        }
+
+        @Test
+        void 이메일_형식이_올바르지_않은_경우_중복_확인에_실패한다() {
+            // given
+            String invalidEmail = "invalid-email";
+
+            // when
+            ThrowingCallable checkEmailDuplicate = () -> userService.checkEmailDuplicate(
+                invalidEmail);
+
+            // then
+            assertThatExceptionOfType(IllegalArgumentException.class).isThrownBy(
+                    checkEmailDuplicate)
+                .withMessage("이메일 형식이 올바르지 않습니다.");
+        }
+    }
+
     private User createUser(String email, String password, String nickname) {
         return User.builder()
             .email(isBlank(email) ? this.email : email)