refactor: Like를 VO로 취급, Likes를 컨테이너로 취급하도록 변경 (#249)

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/application/PostDtoAssembler.java

@@ -7,6 +7,7 @@
 import com.woowacourse.pickgit.post.domain.Post;
 import com.woowacourse.pickgit.post.domain.comment.Comment;
 import com.woowacourse.pickgit.tag.domain.Tag;
+import com.woowacourse.pickgit.user.domain.User;
 import java.util.List;
 import java.util.function.Function;
 
@@ -16,16 +17,16 @@ private PostDtoAssembler() {
     }
 
     public static List<PostResponseDto> assembleFrom(
-        String userName,
+        User requestUser,
         boolean isGuest,
         List<Post> posts
     ) {
         return posts.stream()
-            .map(post -> convertFrom(userName, isGuest, post))
+            .map(post -> convertFrom(requestUser, isGuest, post))
             .collect(toList());
     }
 
-    private static PostResponseDto convertFrom(String userName, boolean isGuest, Post post) {
+    private static PostResponseDto convertFrom(User requestUser, boolean isGuest, Post post) {
         List<String> tags = createTagsFrom(post);
         List<CommentResponseDto> comments = createCommentResponsesFrom(post);
 
@@ -41,7 +42,7 @@ private static PostResponseDto convertFrom(String userName, boolean isGuest, Pos
             .createdAt(post.getCreatedAt())
             .updatedAt(post.getUpdatedAt())
             .comments(comments)
-            .isLiked(isLikedBy(userName, post, isGuest))
+            .isLiked(isLikedBy(requestUser, post, isGuest))
             .build();
     }
 
@@ -69,11 +70,11 @@ private static List<String> createTagsFrom(Post post) {
             .collect(toList());
     }
 
-    private static Boolean isLikedBy(String userName, Post post, boolean isGuest) {
+    private static Boolean isLikedBy(User requestUser, Post post, boolean isGuest) {
         if (isGuest) {
             return null;
         }
 
-        return post.isLikedBy(userName);
+        return post.isLikedBy(requestUser);
     }
 }

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/application/PostFeedService.java

@@ -60,12 +60,18 @@ private List<PostResponseDto> readFeed(HomeFeedRequestDto homeFeedRequestDto,
             .map(target -> postRepository.findAllPostsByUser(target, pageable))
             .orElse(postRepository.findAllPosts(pageable));
 
-        return PostDtoAssembler.assembleFrom(requestUserName, isGuest, result);
+        User requestUser = findUserByName(requestUserName);
+
+        return PostDtoAssembler.assembleFrom(requestUser, isGuest, result);
     }
 
-    private User findUserByName(String username) {
+    private User findUserByName(String userName) {
+        if(Objects.isNull(userName)) {
+            return null;
+        }
+
         return userRepository
-            .findByBasicProfile_Name(username)
+            .findByBasicProfile_Name(userName)
             .orElseThrow(UserNotFoundException::new);
     }
 }

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/domain/Post.java

@@ -7,6 +7,7 @@
 import com.woowacourse.pickgit.post.domain.content.Image;
 import com.woowacourse.pickgit.post.domain.content.Images;
 import com.woowacourse.pickgit.post.domain.content.PostContent;
+import com.woowacourse.pickgit.post.domain.like.Like;
 import com.woowacourse.pickgit.post.domain.like.Likes;
 import com.woowacourse.pickgit.post.domain.tag.PostTags;
 import com.woowacourse.pickgit.tag.domain.Tag;
@@ -104,8 +105,8 @@ public void addTags(List<Tag> tags) {
         postTags.addAll(this, tags);
     }
 
-    public boolean isLikedBy(String userName) {
-        return likes.contains(userName);
+    public boolean isLikedBy(User user) {
+        return likes.contains(new Like(this, user));
     }
 
     public Long getId() {

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/domain/like/Like.java

@@ -40,8 +40,12 @@ public Like(Long id, Post post, User user) {
         this.user = user;
     }
 
-    public boolean isOwnedBy(String userName) {
-        return user.getName().equals(userName);
+    private Post getPost() {
+        return post;
+    }
+
+    private User getUser() {
+        return user;
     }
 
     @Override
@@ -53,11 +57,12 @@ public boolean equals(Object o) {
             return false;
         }
         Like like = (Like) o;
-        return Objects.equals(id, like.id);
+        return Objects.equals(post, like.getPost()) &&
+            Objects.equals(user, like.getUser());
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(id);
+        return Objects.hash(post, user);
     }
 }

backend/pick-git/src/main/java/com/woowacourse/pickgit/post/domain/like/Likes.java

@@ -1,5 +1,6 @@
 package com.woowacourse.pickgit.post.domain.like;
 
+import com.woowacourse.pickgit.user.domain.User;
 import java.util.ArrayList;
 import java.util.List;
 import javax.persistence.Embeddable;
@@ -24,8 +25,8 @@ public int getCounts() {
         return likes.size();
     }
 
-    public boolean contains(String userName) {
+    public boolean contains(Like like) {
         return likes.stream()
-            .anyMatch(like -> like.isOwnedBy(userName));
+            .anyMatch(l -> l.equals(like));
     }
 }

backend/pick-git/src/test/java/com/woowacourse/pickgit/integration/post/PostFeedServiceIntegrationTest.java

@@ -48,6 +48,7 @@ void readHomeFeed_Success() {
         //given
         createMockPosts();
 
+        userRepository.save(UserFactory.user("kevin"));
         HomeFeedRequestDto homeFeedRequestDto = HomeFeedRequestDto.builder()
             .requestUserName("kevin")
             .isGuest(false)

backend/pick-git/src/test/java/com/woowacourse/pickgit/unit/post/application/PostFeedServiceTest.java

@@ -194,7 +194,7 @@ void readUserFeed_validUser_ExceptionOccur() {
 
         assertThat(actual).containsAll(expected);
 
-        verify(userRepository, times(1)).findByBasicProfile_Name(anyString());
+        verify(userRepository, times(2)).findByBasicProfile_Name(anyString());
     }
 
     @DisplayName("게스트 유저는 다른 유저의 홈 피드를 가져온다")
@@ -255,6 +255,8 @@ void readUserFeed_invalidUser_ExceptionOccur() {
 
         given(userRepository.findByBasicProfile_Name("testUser"))
             .willReturn(Optional.of(UserFactory.user("testUser")));
+        given(userRepository.findByBasicProfile_Name("invalidUser"))
+            .willReturn(Optional.of(UserFactory.user("invalidUser")));
         given(postRepository.findAllPostsByUser(any(User.class), any(Pageable.class)))
             .willReturn(posts);
 
@@ -273,6 +275,6 @@ void readUserFeed_invalidUser_ExceptionOccur() {
 
         assertThat(actual).containsAll(expected);
 
-        verify(userRepository, times(1)).findByBasicProfile_Name(anyString());
+        verify(userRepository, times(2)).findByBasicProfile_Name(anyString());
     }
 }

backend/pick-git/src/test/java/com/woowacourse/pickgit/unit/post/application/PostServiceTest.java

@@ -206,11 +206,6 @@ void addComment_InvalidContent_ExceptionThrown() {
 
         User user = UserFactory.user("testuser");
 
-        given(postRepository.findById(anyLong()))
-            .willReturn(Optional.of(post));
-        given(userRepository.findByBasicProfile_Name(user.getName()))
-            .willReturn(Optional.of(user));
-
         CommentRequestDto commentRequestDto =
             new CommentRequestDto(user.getName(), "", post.getId());
 
@@ -219,9 +214,6 @@ void addComment_InvalidContent_ExceptionThrown() {
             .isInstanceOf(CommentFormatException.class)
             .extracting("errorCode")
             .isEqualTo("F0002");
-
-        verify(postRepository, times(1)).findById(anyLong());
-        verify(userRepository, times(1)).findByBasicProfile_Name(anyString());
     }
 
     @DisplayName("존재하지 않는 사용자는 댓글을 등록할 수 없다.")

backend/pick-git/src/test/java/com/woowacourse/pickgit/unit/post/domain/like/LikeTest.java

@@ -11,7 +11,7 @@
 
 class LikeTest {
 
-    @DisplayName("like의 소유자를 판단한다.")
+    @DisplayName("like의 동등성를 판단한다.")
     @Test
     void isOwnedBy() {
         //given
@@ -22,7 +22,7 @@ void isOwnedBy() {
         Like like = new Like(post, user);
 
         //when
-        boolean ownedBy = like.isOwnedBy(userName);
+        boolean ownedBy = like.equals(new Like(post, user));
 
         //then
         assertThat(ownedBy).isTrue();

backend/pick-git/src/test/java/com/woowacourse/pickgit/unit/post/domain/like/LikesTest.java

@@ -17,20 +17,21 @@
 class LikesTest {
 
     private Likes likes;
+    private Post post;
 
     @BeforeEach
     void setUp() {
-        Post post = Post.builder().id(1L).build();
+        post = Post.builder().id(1L).build();
 
-        User testUser1 = UserFactory.user("testUser1");
-        User testUser2 = UserFactory.user("testUser2");
-        User testUser3 = UserFactory.user("testUser3");
+        User testUser1 = UserFactory.user(1L, "testUser1");
+        User testUser2 = UserFactory.user(2L, "testUser2");
+        User testUser3 = UserFactory.user(3L, "testUser3");
 
         likes = new Likes(List.of(
-                new Like(post, testUser1),
-                new Like(post, testUser2),
-                new Like(post, testUser3)
-            ));
+            new Like(post, testUser1),
+            new Like(post, testUser2),
+            new Like(post, testUser3)
+        ));
     }
 
     @DisplayName("like의 개수를 확인한다.")
@@ -41,8 +42,9 @@ void getCounts() {
 
     @DisplayName("특정 사용자의 like가 포함되어 있는지 확인한다.")
     @ParameterizedTest
-    @CsvSource(value = {"testUser1,true", "testUser2,true", "noTestUser1,false"})
-    void contains(String userName, boolean expected) {
-        assertThat(likes.contains(userName)).isEqualTo(expected);
+    @CsvSource(value = {"1, testUser1, true", "2,testUser2, true", "4, noTestUser1, false"})
+    void contains(Long id, String userName, boolean expected) {
+        User user = UserFactory.user(id, userName);
+        assertThat(likes.contains(new Like(post, user))).isEqualTo(expected);
     }
 }