[User] 친구삭제 API 구현

user/src/main/kotlin/kpring/user/dto/response/DeleteFriendResponse.kt

@@ -0,0 +1,5 @@
+package kpring.user.dto.response
+
+data class DeleteFriendResponse(
+  val friendId: Long,
+)

user/src/main/kotlin/kpring/user/entity/User.kt

@@ -16,7 +16,12 @@ class User(
   @Column(nullable = false)
   var password: String,
   var file: String?,
-  @OneToMany(fetch = FetchType.LAZY, mappedBy = "user", cascade = [CascadeType.ALL])
+  @OneToMany(
+    fetch = FetchType.LAZY,
+    mappedBy = "user",
+    cascade = [CascadeType.ALL],
+    orphanRemoval = true,
+  )
   val friends: MutableSet<Friend> = mutableSetOf(),
   // Other fields and methods...
 ) {
@@ -40,6 +45,11 @@ class User(
     friends.add(friendRelation)
   }
 
+  fun removeFriendRelation(friendRelation: Friend) {
+    friends.remove(friendRelation)
+    friendRelation.friend.friends.removeIf { it.friend == this }
+  }
+
   fun updateInfo(
     request: UpdateUserProfileRequest,
     newPassword: String?,

user/src/main/kotlin/kpring/user/exception/UserErrorCode.kt

@@ -19,11 +19,11 @@ enum class UserErrorCode(
 
   ALREADY_FRIEND(HttpStatus.BAD_REQUEST, "4030", "이미 친구입니다."),
   NOT_SELF_FOLLOW(HttpStatus.BAD_REQUEST, "4031", "자기자신에게 친구요청을 보낼 수 없습니다"),
-  FRIENDSHIP_ALREADY_EXISTS_OR_NOT_FOUND(
-    HttpStatus.BAD_REQUEST,
-    "4032",
-    "해당하는 친구신청이 없거나 이미 친구입니다.",
-  ),
+
+  FRIENDSHIP_ALREADY_EXISTS(HttpStatus.BAD_REQUEST, "4032", "이미 친구입니다."),
+  FRIENDSHIP_NOT_FOUND(HttpStatus.NOT_FOUND, "4033", "해당하는 친구신청이 없습니다."),
+
+  FRIEND_NOT_FOUND(HttpStatus.NOT_FOUND, "4034", "해당하는 친구가 없습니다."),
   ;
 
   override fun message(): String = this.message

user/src/main/kotlin/kpring/user/repository/FriendRepository.kt

@@ -20,4 +20,9 @@ interface FriendRepository : JpaRepository<Friend, Long> {
     friendId: Long,
     requestStatus: FriendRequestStatus,
   ): Friend?
+
+  fun findByUserIdAndFriendId(
+    userId: Long,
+    friendId: Long,
+  ): Friend?
 }

user/src/main/kotlin/kpring/user/service/FriendService.kt

@@ -46,6 +46,14 @@ interface FriendService {
     friendId: Long,
   ): AddFriendResponse
 
+  /***
+   * 사용자가 친구와의 관계를 끊을 때 친구 상태를 삭제하는 메서드
+   *
+   * @param userId : 로그인한 사용자 ID.
+   * @param friendId : 기존에 친구였지만 친구관계를 삭제하고자 하는 사용자 ID.
+   * @return 전에 친구였던 사용자의 ID를 담고 있는 DeleteFriendResponse 리턴
+   * @throws FRIEND_NOT_FOUND : 친구 중에 friendId 를 가진 사용자가 없을 경우 발생하는 예외
+   */
   fun deleteFriend(
     userId: Long,
     friendId: Long,

user/src/main/kotlin/kpring/user/service/FriendServiceImpl.kt

@@ -53,8 +53,8 @@ class FriendServiceImpl(
     userId: Long,
     friendId: Long,
   ): AddFriendResponse {
-    val receivedFriend = getFriendshipWithStatus(userId, friendId, FriendRequestStatus.RECEIVED)
-    val requestedFriend = getFriendshipWithStatus(friendId, userId, FriendRequestStatus.REQUESTED)
+    val receivedFriend = getPendingFriendship(userId, friendId)
+    val requestedFriend = getPendingFriendship(friendId, userId)
 
     receivedFriend.updateRequestStatus(FriendRequestStatus.ACCEPTED)
     requestedFriend.updateRequestStatus(FriendRequestStatus.ACCEPTED)
@@ -66,7 +66,13 @@ class FriendServiceImpl(
     userId: Long,
     friendId: Long,
   ): DeleteFriendResponse {
-    TODO("Not yet implemented")
+    val user = userServiceImpl.getUser(userId)
+    userServiceImpl.getUser(friendId)
+
+    val userFriendRelation = findAcceptedFriendship(userId, friendId)
+    user.removeFriendRelation(userFriendRelation)
+
+    return DeleteFriendResponse(friendId)
   }
 
   fun checkSelfFriend(
@@ -87,13 +93,37 @@ class FriendServiceImpl(
     }
   }
 
-  private fun getFriendshipWithStatus(
+  private fun findFriendship(
+    userId: Long,
+    friendId: Long,
+  ): Friend {
+    val friendship =
+      friendRepository.findByUserIdAndFriendId(userId, friendId)
+        ?: throw ServiceException(UserErrorCode.FRIENDSHIP_NOT_FOUND)
+    return friendship
+  }
+
+  private fun checkNotAcceptedFriendship(friendship: Friend) {
+    if (friendship.requestStatus == FriendRequestStatus.ACCEPTED) {
+      throw ServiceException(UserErrorCode.FRIENDSHIP_ALREADY_EXISTS)
+    }
+  }
+
+  private fun getPendingFriendship(
+    userId: Long,
+    friendId: Long,
+  ): Friend {
+    val friendship = findFriendship(userId, friendId)
+    checkNotAcceptedFriendship(friendship)
+    return friendship
+  }
+
+  private fun findAcceptedFriendship(
     userId: Long,
     friendId: Long,
-    requestStatus: FriendRequestStatus,
   ): Friend {
     return friendRepository
-      .findByUserIdAndFriendIdAndRequestStatus(userId, friendId, requestStatus)
-      ?: throw ServiceException(UserErrorCode.FRIENDSHIP_ALREADY_EXISTS_OR_NOT_FOUND)
+      .findByUserIdAndFriendIdAndRequestStatus(userId, friendId, FriendRequestStatus.ACCEPTED)
+      ?: throw ServiceException(UserErrorCode.FRIEND_NOT_FOUND)
   }
 }

user/src/test/kotlin/kpring/user/controller/FriendControllerTest.kt

@@ -13,10 +13,7 @@ import kpring.core.global.exception.ServiceException
 import kpring.test.restdoc.dsl.restDoc
 import kpring.test.restdoc.json.JsonDataType
 import kpring.test.restdoc.json.JsonDataType.Strings
-import kpring.user.dto.response.AddFriendResponse
-import kpring.user.dto.response.FailMessageResponse
-import kpring.user.dto.response.GetFriendRequestResponse
-import kpring.user.dto.response.GetFriendRequestsResponse
+import kpring.user.dto.response.*
 import kpring.user.exception.UserErrorCode
 import kpring.user.global.AuthValidator
 import kpring.user.global.CommonTest
@@ -492,5 +489,154 @@ internal class FriendControllerTest(
             }
           }
       }
+
+      describe("친구삭제 API") {
+        it("친구삭제 성공") {
+          // given
+          val data = DeleteFriendResponse(friendId = CommonTest.TEST_FRIEND_ID)
+
+          val response = ApiResponse(data = data)
+          every { authClient.getTokenInfo(any()) }.returns(
+            ApiResponse(data = TokenInfo(TokenType.ACCESS, CommonTest.TEST_USER_ID.toString())),
+          )
+          every { authValidator.checkIfAccessTokenAndGetUserId(any()) } returns CommonTest.TEST_USER_ID.toString()
+          every { authValidator.checkIfUserIsSelf(any(), any()) } returns Unit
+          every {
+            friendService.deleteFriend(
+              CommonTest.TEST_USER_ID,
+              CommonTest.TEST_FRIEND_ID,
+            )
+          } returns data
+
+          // when
+          val result =
+            webTestClient.delete()
+              .uri(
+                "/api/v1/user/{userId}/friend/{friendId}",
+                CommonTest.TEST_USER_ID,
+                CommonTest.TEST_FRIEND_ID,
+              )
+              .header("Authorization", CommonTest.TEST_TOKEN)
+              .exchange()
+
+          // then
+          val docsRoot =
+            result
+              .expectStatus().isOk
+              .expectBody().json(objectMapper.writeValueAsString(response))
+
+          // docs
+          docsRoot
+            .restDoc(
+              identifier = "deleteFriend200",
+              description = "친구삭제 API",
+            ) {
+              request {
+                path {
+                  "userId" mean "사용자 아이디"
+                  "friendId" mean "친구신청을 받은 사용자의 아이디"
+                }
+                header {
+                  "Authorization" mean "Bearer token"
+                }
+              }
+              response {
+                body {
+                  "data.friendId" type Strings mean "친구신청을 받은 사용자의 아이디"
+                }
+              }
+            }
+        }
+        it("친구삭제 실패 : 권한이 없는 토큰") {
+          // given
+          val response =
+            FailMessageResponse.builder().message(UserErrorCode.NOT_ALLOWED.message()).build()
+          every { authClient.getTokenInfo(any()) } throws ServiceException(UserErrorCode.NOT_ALLOWED)
+
+          // when
+          val result =
+            webTestClient.delete()
+              .uri(
+                "/api/v1/user/{userId}/friend/{friendId}",
+                CommonTest.TEST_USER_ID,
+                CommonTest.TEST_FRIEND_ID,
+              )
+              .header("Authorization", CommonTest.TEST_TOKEN)
+              .exchange()
+
+          // then
+          val docsRoot =
+            result
+              .expectStatus().isForbidden
+              .expectBody().json(objectMapper.writeValueAsString(response))
+
+          // docs
+          docsRoot
+            .restDoc(
+              identifier = "deleteFriend403",
+              description = "친구삭제 API",
+            ) {
+              request {
+                path {
+                  "userId" mean "사용자 아이디"
+                  "friendId" mean "친구신청을 받은 사용자의 아이디"
+                }
+                header {
+                  "Authorization" mean "Bearer token"
+                }
+              }
+              response {
+                body {
+                  "message" type Strings mean "에러 메시지"
+                }
+              }
+            }
+        }
+        it("친구삭제 실패 : 서버 내부 오류") {
+          // given
+          val response =
+            FailMessageResponse.serverError
+          every { authClient.getTokenInfo(any()) } throws RuntimeException("서버 내부 오류")
+
+          // when
+          val result =
+            webTestClient.delete()
+              .uri(
+                "/api/v1/user/{userId}/friend/{friendId}",
+                CommonTest.TEST_USER_ID,
+                CommonTest.TEST_FRIEND_ID,
+              )
+              .header("Authorization", CommonTest.TEST_TOKEN)
+              .exchange()
+
+          // then
+          val docsRoot =
+            result
+              .expectStatus().isEqualTo(500)
+              .expectBody().json(objectMapper.writeValueAsString(response))
+
+          // docs
+          docsRoot
+            .restDoc(
+              identifier = "deleteFriend500",
+              description = "친구삭제 API",
+            ) {
+              request {
+                path {
+                  "userId" mean "사용자 아이디"
+                  "friendId" mean "친구신청을 받은 사용자의 아이디"
+                }
+                header {
+                  "Authorization" mean "Bearer token"
+                }
+              }
+              response {
+                body {
+                  "message" type Strings mean "에러 메시지"
+                }
+              }
+            }
+        }
+      }
     }
   })