feature/#109 Post 테스트 코드 작성 (#117)

* feat: Post 도메인 성공 테스트 및 클래스 생성

* refactor: Post 도메인 테스트 수정

* feat: PostServiceTest 코드 작성을 위한 세팅

* fix: 테스트 중 발견한 createPost 오류 수정

* feat: createPost 테스트 구현

* feat: createdAt을 사용하지 않는 테스트 구현

* feat: TestEntityUtils를 적용해 createdAt 사용 테스트 구현

* fix: CodeRabbit 리뷰 반영, 테스트 케이스 수정 및 null 체크 보완

* fix: FakeUserService 삭제 후 테스트용SecurityContext 대체

* fix: UserServiceTest 초기화 부분 수정

aics-api/src/main/java/kgu/developers/api/post/application/PostService.java

@@ -1,13 +1,5 @@
 package kgu.developers.api.post.application;
 
-import java.time.LocalDateTime;
-import java.time.format.DateTimeFormatter;
-
-import org.springframework.data.domain.PageRequest;
-import org.springframework.scheduling.annotation.Scheduled;
-import org.springframework.stereotype.Service;
-import org.springframework.transaction.annotation.Transactional;
-
 import kgu.developers.api.post.presentation.exception.PostNotFoundException;
 import kgu.developers.api.post.presentation.request.PostRequest;
 import kgu.developers.api.post.presentation.response.PostDetailResponse;
@@ -20,6 +12,13 @@
 import kgu.developers.domain.post.domain.PostRepository;
 import kgu.developers.domain.user.domain.User;
 import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
 
 @Service
 @RequiredArgsConstructor
@@ -35,12 +34,12 @@ public class PostService {
 	public PostPersistResponse createPost(PostRequest request, Category category) {
 		User author = userService.me();
 		Post createPost = Post.create(request.title(), request.content(), category, author);
-		postRepository.save(createPost);
-		return PostPersistResponse.from(createPost.getId());
+		Long id = postRepository.save(createPost).getId();
+		return PostPersistResponse.from(id);
 	}
 
 	public PostSummaryPageResponse getPostsByKeywordAndCategory(PageRequest request, String keyword,
-		Category category) {
+																Category category) {
 		PaginatedListResponse<Post> paginatedListResponse = postRepository.findAllByTitleContainingAndCategoryOrderByCreatedAtDesc(
 			keyword, category, request);
 		return PostSummaryPageResponse.of(paginatedListResponse.contents(), paginatedListResponse.pageable());

aics-api/src/main/java/kgu/developers/api/post/presentation/request/PostRequest.java

@@ -5,7 +5,9 @@
 import io.swagger.v3.oas.annotations.media.Schema;
 import jakarta.validation.constraints.NotBlank;
 import jakarta.validation.constraints.Size;
+import lombok.Builder;
 
+@Builder
 public record PostRequest(
 	@Schema(description = "게시물 제목", example = "SW 부트캠프 4기 교육생 모집", requiredMode = REQUIRED)
 	@NotBlank

aics-api/src/testFixtures/java/post/application/PostServiceTest.java

@@ -0,0 +1,166 @@
+package post.application;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+
+import kgu.developers.api.post.application.PostService;
+import kgu.developers.api.post.presentation.exception.PostNotFoundException;
+import kgu.developers.api.post.presentation.request.PostRequest;
+import kgu.developers.api.post.presentation.response.PostDetailResponse;
+import kgu.developers.api.post.presentation.response.PostPersistResponse;
+import kgu.developers.api.post.presentation.response.PostSummaryPageResponse;
+import kgu.developers.api.user.application.UserService;
+import kgu.developers.domain.post.domain.Category;
+import kgu.developers.domain.post.domain.Post;
+import kgu.developers.domain.user.domain.Major;
+import kgu.developers.domain.user.domain.User;
+import mock.FakePostRepository;
+import mock.FakeUserRepository;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
+import org.springframework.security.core.context.SecurityContext;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
+
+public class PostServiceTest {
+	private PostService postService;
+
+	@BeforeEach
+	public void init() {
+		FakePostRepository fakePostRepository = new FakePostRepository();
+		BCryptPasswordEncoder bCryptPasswordEncoder = new BCryptPasswordEncoder();
+		FakeUserRepository fakeUserRepository = new FakeUserRepository();
+		UserService userService = new UserService(bCryptPasswordEncoder, fakeUserRepository);
+
+		this.postService = new PostService(fakePostRepository, userService);
+
+		fakeUserRepository.save(User.builder()
+			.id("202411345")
+			.password(bCryptPasswordEncoder.encode("password1234"))
+			.name("홍길동")
+			.email("[email protected]")
+			.phone("010-1234-5678")
+			.major(Major.CSE)
+			.build());
+
+		UserDetails user = userService.getUserById("202411345");
+		SecurityContext context = SecurityContextHolder.getContext();
+		context.setAuthentication(
+			new UsernamePasswordAuthenticationToken(user, user.getPassword(), user.getAuthorities())
+		);
+
+		fakePostRepository.save(Post.create(
+			"테스트용 제목1", "테스트용 내용1",
+			Category.DEPT_INFO, userService.getUserById("202411345")
+		));
+
+		fakePostRepository.save(Post.create(
+			"테스트용 제목2", "테스트용 내용2",
+			Category.DEPT_INFO, userService.getUserById("202411345")
+		));
+	}
+
+	@Test
+	@DisplayName("createPost는 게시글을 생성할 수 있다")
+	public void createPost_Success() {
+		// given
+		PostRequest request = PostRequest.builder()
+			.title("테스트용 제목3")
+			.content("테스트용 내용3")
+			.build();
+		Category category = Category.DEPT_INFO;
+
+		// when
+		PostPersistResponse response = postService.createPost(request, category);
+
+		// then
+		assertEquals(3, response.postId());
+
+		// when
+		PostDetailResponse created = postService.getPostById(response.postId());
+
+		// then
+		assertEquals(request.title(), created.title());
+		assertEquals(request.content(), created.content());
+		assertEquals(category.getDescription(), created.category());
+	}
+
+	@Test
+	@DisplayName("getPostById는 게시글을 조회할 수 있다")
+	public void getPostById_Success() {
+		// given
+		Long postId = 1L;
+
+		// when
+		PostDetailResponse response = postService.getPostById(postId);
+
+		// then
+		assertEquals(postId, response.postId());
+	}
+
+	@Test
+	@DisplayName("getPostById는 존재하지 않는 ID로 조회시 PostNotFoundException을 발생시킨다")
+	public void getPostById_Throws_PostNotFoundException() {
+		// given
+		Long postId = 10L;
+
+		// when
+		// then
+		assertThatThrownBy(
+			() -> postService.getPostById(postId)
+		).isInstanceOf(PostNotFoundException.class);
+	}
+
+	@Test
+	@DisplayName("getPostsByKeywordAndCategory는 게시글을 페이징 조회할 수 있다")
+	public void getPostsByKeywordAndCategory_Success() {
+		// given
+		String keyword = "제목";
+		Category category = Category.DEPT_INFO;
+		int page = 0;
+		int size = 10;
+
+		// when
+		PostSummaryPageResponse posts = postService.getPostsByKeywordAndCategory(
+			PageRequest.of(page, size), keyword, category
+		);
+
+		// then
+		assertEquals(2, posts.contents().size());
+	}
+
+	@Test
+	@DisplayName("togglePostPinStatus는 게시글의 고정 상태를 변경할 수 있다")
+	public void togglePostPinStatus_Success() {
+		// given
+		Long postId = 1L;
+		PostDetailResponse before = postService.getPostById(postId);
+
+		// when
+		postService.togglePostPinStatus(postId);
+
+		// then
+		PostDetailResponse after = postService.getPostById(postId);
+		assertNotEquals(before.isPinned(), after.isPinned());
+	}
+
+	@Test
+	@DisplayName("deletePost 이후 게시글을 조회할 수 없다")
+	public void deletePost_Throws_PostNotFoundException() {
+		// given
+		Long postId = 1L;
+
+		// when
+		postService.deletePost(postId);
+
+		// then
+		assertThatThrownBy(
+			() -> postService.getPostById(postId)
+		).isInstanceOf(PostNotFoundException.class);
+	}
+}

aics-api/src/testFixtures/java/post/presentation/PostControllerTest.java

@@ -0,0 +1,4 @@
+package post.presentation;
+
+public class PostControllerTest {
+}

aics-domain/src/testFixtures/java/mock/FakePostRepository.java

@@ -0,0 +1,87 @@
+package mock;
+
+import kgu.developers.common.response.PageableResponse;
+import kgu.developers.common.response.PaginatedListResponse;
+import kgu.developers.domain.post.domain.Category;
+import kgu.developers.domain.post.domain.Post;
+import kgu.developers.domain.post.domain.PostRepository;
+import org.springframework.data.domain.Pageable;
+
+import java.time.LocalDateTime;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Optional;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.stream.Collectors;
+
+public class FakePostRepository implements PostRepository {
+	private final List<Post> data = Collections.synchronizedList(new ArrayList<>());
+	private final AtomicLong autoGeneratedId = new AtomicLong(0);
+
+	@Override
+	public Post save(Post post) {
+		if (post == null) {
+			throw new IllegalArgumentException("게시글은 null일 수 없습니다.");
+		}
+		if (post.getTitle() == null || post.getContent() == null) {
+			throw new IllegalArgumentException("제목과 내용은 필수 입력값입니다.");
+		}
+
+		Post newPost = Post.builder()
+			.id(autoGeneratedId.incrementAndGet())
+			.title(post.getTitle())
+			.content(post.getContent())
+			.views(post.getViews())
+			.category(post.getCategory())
+			.author(post.getAuthor())
+			.isPinned(post.isPinned())
+			.comments(new ArrayList<>(post.getComments()))
+			.file(post.getFile())
+			.build();
+
+		TestEntityUtils.setCreatedAt(newPost, LocalDateTime.now());
+
+		data.add(newPost);
+		return newPost;
+	}
+
+	@Override
+	public PaginatedListResponse<Post> findAllByTitleContainingAndCategoryOrderByCreatedAtDesc(
+		String keyword, Category category, Pageable pageable
+	) {
+		List<Post> filteredPosts = data.stream()
+			.filter(
+				post -> post.getTitle().contains(keyword) && post.getCategory().equals(category)
+			)
+			.sorted(Comparator.comparing(Post::getCreatedAt).reversed())
+			.collect(Collectors.toList());
+
+		int start = (int) pageable.getOffset();
+		int end = Math.min(start + pageable.getPageSize(), filteredPosts.size());
+
+		List<Post> paginatedPosts = start > filteredPosts.size() ?
+			Collections.emptyList() :
+			filteredPosts.subList(start, end);
+
+		List<Long> ids = paginatedPosts.stream()
+			.map(Post::getId)
+			.toList();
+
+		return PaginatedListResponse.of(paginatedPosts, PageableResponse.of(pageable, ids));
+	}
+
+	@Override
+	public Optional<Post> findById(Long postId) {
+		return data.stream()
+			.filter(post -> post.getId().equals(postId))
+			.findAny();
+	}
+
+	@Override
+	public void deleteAllByDeletedAtBefore(int retentionDays) {
+		LocalDateTime threshold = LocalDateTime.now().minusDays(retentionDays);
+		data.removeIf(post -> post.getDeletedAt() != null && post.getDeletedAt().isBefore(threshold));
+	}
+}

aics-domain/src/testFixtures/java/mock/TestEntityUtils.java

@@ -0,0 +1,23 @@
+package mock;
+
+import kgu.developers.common.domain.BaseTimeEntity;
+
+import java.lang.reflect.Field;
+import java.time.LocalDateTime;
+
+public class TestEntityUtils {
+	public static void setCreatedAt(BaseTimeEntity entity, LocalDateTime createdAt) {
+		if (entity == null || createdAt == null) {
+			throw new IllegalArgumentException("entity와 createdAt은 null이 될 수 없습니다.");
+		}
+
+		try {
+			Field field = BaseTimeEntity.class.getDeclaredField("createdAt");
+			field.setAccessible(true);
+			field.set(entity, createdAt);
+		} catch (NoSuchFieldException | IllegalAccessException e) {
+			throw new RuntimeException("TestEntityUtils에서 createdAt 설정 실패", e);
+		}
+	}
+}
+

aics-domain/src/testFixtures/java/post/application/PostServiceTest.java

@@ -0,0 +1,4 @@
+package post.application;
+
+public class PostServiceTest {
+}