fix: 채널 수정 시 유니크 제약 위반하지 않도록

Author: nayonsoso

src/main/java/com/example/solidconnection/mentor/domain/Channel.java

@@ -55,11 +55,9 @@ public void updateMentor(Mentor mentor) {
         this.mentor = mentor;
     }
 
-    public void updateType(ChannelType type) {
-        this.type = type;
-    }
-
-    public void updateUrl(String url) {
-        this.url = url;
+    public void update(Channel channel) {
+        this.sequence = channel.sequence;
+        this.type = channel.type;
+        this.url = channel.url;
     }
 }

src/main/java/com/example/solidconnection/mentor/domain/Mentor.java

@@ -64,16 +64,20 @@ public void updatePassTip(String passTip) {
         this.passTip = passTip;
     }
 
-    public void updateChannels(List<Channel> newChannels) {
-        for (int i = 0; i < newChannels.size(); i++) {
-            Channel newChannel = newChannels.get(i);
-            if (i < this.channels.size()) {
+    public void updateChannels(List<Channel> channels) {
+        int newChannelSize = Math.max(channels.size(), this.channels.size());
+        int originalChannelSize = this.channels.size();
+        for (int i = 0; i < newChannelSize; i++) {
+            if (i < channels.size() && i < this.channels.size()) { // 기존 채널 수정
                 Channel existing = this.channels.get(i);
-                existing.updateType(newChannel.getType());
-                existing.updateUrl(newChannel.getUrl());
-            } else {
+                Channel newChannel = channels.get(i);
+                existing.update(newChannel);
+            } else if (i < channels.size()) { // 채널 갯수 늘어남 - 새로운 채널 추가
+                Channel newChannel = channels.get(i);
                 newChannel.updateMentor(this);
                 this.channels.add(newChannel);
+            } else if (i < originalChannelSize) { // 채널 갯수 줄어듦 - 기존 채널 삭제
+                this.channels.remove(this.channels.size() - 1);
             }
         }
     }

src/test/java/com/example/solidconnection/mentor/service/MentorMyPageServiceTest.java

@@ -110,7 +110,26 @@ class 멘토의_마이_페이지를_수정한다 {
         }
 
         @Test
-        void 채널_정보를_수정한다() {
+        void 기존보다_적게_채널_정보를_수정한다() {
+            // given
+            channelFixture.채널(1, mentor);
+            channelFixture.채널(2, mentor);
+            channelFixture.채널(3, mentor);
+            channelFixture.채널(4, mentor);
+            List<ChannelRequest> newChannels = List.of(new ChannelRequest(BLOG, "https://blog.com"));
+            MentorMyPageUpdateRequest request = new MentorMyPageUpdateRequest("introduction", "passTip", newChannels);
+
+            // when
+            mentorMyPageService.updateMentorMyPage(mentorUser.getId(), request);
+
+            // then
+            List<Channel> updatedChannels = channelRepositoryForTest.findAllByMentorId(mentor.getId());
+            assertThat(updatedChannels).extracting(Channel::getSequence, Channel::getType, Channel::getUrl)
+                    .containsExactlyInAnyOrder(tuple(1, BLOG, "https://blog.com"));
+        }
+
+        @Test
+        void 기존보다_많게_채널_정보를_수정한다() {
             // given
             channelFixture.채널(1, mentor);
             List<ChannelRequest> newChannels = List.of(