refactor: 회원 도메인에서의 새로운 커스텀 예외 적용 및 공통 로직 DSL 처리

src/main/kotlin/roomescape/member/business/MemberService.kt

@@ -1,11 +1,10 @@
 package roomescape.member.business
 
 import org.springframework.data.repository.findByIdOrNull
-import org.springframework.http.HttpStatus
 import org.springframework.stereotype.Service
 import org.springframework.transaction.annotation.Transactional
-import roomescape.common.exception.ErrorType
-import roomescape.common.exception.RoomescapeException
+import roomescape.member.exception.MemberErrorCode
+import roomescape.member.exception.MemberException
 import roomescape.member.infrastructure.persistence.MemberEntity
 import roomescape.member.infrastructure.persistence.MemberRepository
 import roomescape.member.web.MemberRetrieveListResponse
@@ -17,24 +16,18 @@ class MemberService(
         private val memberRepository: MemberRepository
 ) {
     fun findMembers(): MemberRetrieveListResponse = MemberRetrieveListResponse(
-            memberRepository.findAll()
-                    .map { it.toRetrieveResponse() }
-                    .toList()
+            members = memberRepository.findAll().map { it.toRetrieveResponse() }
     )
 
-    fun findById(memberId: Long): MemberEntity = memberRepository.findByIdOrNull(memberId)
-            ?: throw RoomescapeException(
-                    ErrorType.MEMBER_NOT_FOUND,
-                    String.format("[memberId: %d]", memberId),
-                    HttpStatus.BAD_REQUEST
-            )
-
-    fun findByEmailAndPassword(email: String, password: String): MemberEntity =
-            memberRepository.findByEmailAndPassword(email, password)
-                    ?: throw RoomescapeException(
-                            ErrorType.MEMBER_NOT_FOUND,
-                            String.format("[email: %s, password: %s]", email, password),
-                            HttpStatus.BAD_REQUEST
-                    )
+    fun findById(memberId: Long): MemberEntity = fetchOrThrow {
+        memberRepository.findByIdOrNull(memberId)
     }
 
+    fun findByEmailAndPassword(email: String, password: String): MemberEntity = fetchOrThrow {
+        memberRepository.findByEmailAndPassword(email, password)
+    }
+
+    private fun fetchOrThrow(block: () -> MemberEntity?): MemberEntity {
+        return block() ?: throw MemberException(MemberErrorCode.MEMBER_NOT_FOUND)
+    }
+}

src/main/kotlin/roomescape/member/exception/MemberErrorCode.kt

@@ -0,0 +1,12 @@
+package roomescape.member.exception
+
+import org.springframework.http.HttpStatus
+import roomescape.common.exception.ErrorCode
+
+enum class MemberErrorCode(
+        override val httpStatus: HttpStatus,
+        override val errorCode: String,
+        override val message: String
+) : ErrorCode {
+    MEMBER_NOT_FOUND(HttpStatus.NOT_FOUND, "M001", "회원을 찾을 수 없어요.")
+}

src/main/kotlin/roomescape/member/exception/MemberException.kt

@@ -0,0 +1,8 @@
+package roomescape.member.exception
+
+import roomescape.common.exception.RoomescapeExceptionV2
+
+class MemberException(
+        override val errorCode: MemberErrorCode,
+        override val message: String = errorCode.message
+) : RoomescapeExceptionV2(errorCode, message)