test: Leaderboard 조회 API 서비스, 리포지토리 계층 단위 테스트 추가

Author: ooheunda

src/repositories/__test__/leaderboard.repo.test.ts

@@ -0,0 +1,271 @@
+import { DBError } from '@/exception';
+import { LeaderboardRepository } from '@/repositories/leaderboard.repository';
+import { Pool, QueryResult } from 'pg';
+
+jest.mock('pg');
+
+const mockPool: {
+  query: jest.Mock<Promise<QueryResult<Record<string, unknown>>>, unknown[]>;
+} = {
+  query: jest.fn(),
+};
+
+describe('LeaderboardRepository', () => {
+  let repo: LeaderboardRepository;
+
+  beforeEach(() => {
+    repo = new LeaderboardRepository(mockPool as unknown as Pool);
+  });
+
+  describe('getLeaderboard', () => {
+    it('type이 post인 경우 post 데이터를 반환해야 한다.', async () => {
+      const mockResult = [
+        {
+          id: 2,
+          title: 'test2',
+          slug: 'test2',
+          total_views: 200,
+          total_likes: 100,
+          view_diff: 20,
+          like_diff: 10,
+          released_at: '2025-01-02',
+        },
+        {
+          id: 1,
+          title: 'test',
+          slug: 'test',
+          total_views: 100,
+          total_likes: 50,
+          view_diff: 10,
+          like_diff: 5,
+          released_at: '2025-01-01',
+        },
+      ];
+
+      mockPool.query.mockResolvedValue({
+        rows: mockResult,
+        rowCount: mockResult.length,
+      } as unknown as QueryResult);
+
+      const result = await repo.getLeaderboard('post', 'viewCount', 30, 10);
+
+      expect(result).toEqual(mockResult);
+      expect(mockPool.query).toHaveBeenCalledWith(expect.stringContaining('FROM posts_post p'), expect.anything());
+    });
+
+    it('type이 user인 경우 user 데이터를 반환해야 한다.', async () => {
+      const mockResult = [
+        {
+          id: 1,
+          email: 'test@test.com',
+          total_views: 100,
+          total_likes: 50,
+          total_posts: 1,
+          view_diff: 20,
+          like_diff: 10,
+          post_diff: 1,
+        },
+        {
+          id: 2,
+          email: 'test2@test.com',
+          total_views: 200,
+          total_likes: 100,
+          total_posts: 2,
+          view_diff: 10,
+          like_diff: 5,
+          post_diff: 1,
+        },
+      ];
+
+      mockPool.query.mockResolvedValue({
+        rows: mockResult,
+        rowCount: mockResult.length,
+      } as unknown as QueryResult);
+
+      const result = await repo.getLeaderboard('user', 'viewCount', 30, 10);
+
+      expect(mockPool.query).toHaveBeenCalledWith(expect.stringContaining('FROM users_user u'), expect.anything());
+      expect(result).toEqual(mockResult);
+    });
+
+    it('sort가 조회수인 경우 정렬 순서를 보장해야 한다.', async () => {
+      const mockResult = [
+        { view_diff: 20, like_diff: 5, post_diff: 1 },
+        { view_diff: 10, like_diff: 10, post_diff: 2 },
+      ];
+
+      mockPool.query.mockResolvedValue({
+        rows: mockResult,
+        rowCount: mockResult.length,
+      } as unknown as QueryResult);
+
+      const result = await repo.getLeaderboard('user', 'viewCount', 30, 10);
+
+      expect(result).toEqual(mockResult);
+      expect(result[0].view_diff).toBeGreaterThan(result[1].view_diff);
+    });
+
+    it('sort가 좋아요 수인 경우 정렬 순서를 보장해야 한다.', async () => {
+      const mockResult = [
+        { view_diff: 10, like_diff: 10, post_diff: 1 },
+        { view_diff: 20, like_diff: 5, post_diff: 1 },
+      ];
+
+      mockPool.query.mockResolvedValue({
+        rows: mockResult,
+        rowCount: mockResult.length,
+      } as unknown as QueryResult);
+
+      const result = await repo.getLeaderboard('user', 'likeCount', 30, 10);
+
+      expect(result).toEqual(mockResult);
+      expect(result[0].like_diff).toBeGreaterThan(result[1].like_diff);
+    });
+
+    it('sort가 게시물 수인 경우 정렬 순서를 보장해야 한다.', async () => {
+      const mockResult = [
+        { view_diff: 10, like_diff: 10, post_diff: 4 },
+        { view_diff: 20, like_diff: 5, post_diff: 1 },
+      ];
+
+      mockPool.query.mockResolvedValue({
+        rows: mockResult,
+        rowCount: mockResult.length,
+      } as unknown as QueryResult);
+
+      const result = await repo.getLeaderboard('user', 'postCount', 30, 10);
+
+      expect(result).toEqual(mockResult);
+      expect(result[0].post_diff).toBeGreaterThan(result[1].post_diff);
+    });
+
+    it('limit 만큼의 데이터만 반환해야 한다', async () => {
+      const mockData = [
+        { id: 1, title: 'test' },
+        { id: 2, title: 'test2' },
+        { id: 3, title: 'test3' },
+        { id: 4, title: 'test4' },
+        { id: 5, title: 'test5' },
+      ];
+      const mockLimit = 5;
+
+      mockPool.query.mockResolvedValue({
+        rows: mockData,
+        rowCount: mockData.length,
+      } as unknown as QueryResult);
+
+      const result = await repo.getLeaderboard('post', 'viewCount', 30, mockLimit);
+
+      expect(result).toEqual(mockData);
+      expect(result.length).toEqual(mockLimit);
+
+      expect(mockPool.query).toHaveBeenCalledWith(
+        expect.stringContaining('LIMIT $2'),
+        expect.arrayContaining([30, mockLimit]),
+      );
+    });
+
+    it('type이 post이고 sort가 게시물 수인 경우 조회수를 기준으로 정렬해야 한다.', async () => {
+      const mockResult = [
+        { total_views: 200, total_likes: 5, view_diff: 20, like_diff: 0 },
+        { total_views: 100, total_likes: 50, view_diff: 10, like_diff: 5 },
+      ];
+
+      mockPool.query.mockResolvedValue({
+        rows: mockResult,
+        rowCount: mockResult.length,
+      } as unknown as QueryResult);
+
+      const result = await repo.getLeaderboard('post', 'postCount', 30, 10);
+
+      expect(result).toEqual(mockResult);
+      expect(mockPool.query).toHaveBeenCalledWith(
+        expect.stringContaining('ORDER BY view_diff DESC'),
+        expect.anything(),
+      );
+      expect(result[0].view_diff).toBeGreaterThan(result[1].view_diff);
+    });
+
+    it('user 타입에는 GROUP BY 절이 포함되어야 한다', async () => {
+      mockPool.query.mockResolvedValue({
+        rows: [],
+        rowCount: 0,
+      } as unknown as QueryResult);
+
+      await repo.getLeaderboard('user', 'viewCount', 30, 10);
+
+      expect(mockPool.query).toHaveBeenCalledWith(expect.stringContaining('GROUP BY u.id'), expect.anything());
+    });
+
+    it('post 타입에는 GROUP BY 절이 포함되지 않아야 한다', async () => {
+      mockPool.query.mockResolvedValue({
+        rows: [],
+        rowCount: 0,
+      } as unknown as QueryResult);
+
+      await repo.getLeaderboard('post', 'viewCount', 30, 10);
+
+      expect(mockPool.query).toHaveBeenCalledWith(expect.not.stringContaining('GROUP BY'), expect.anything());
+    });
+
+    it('dateRange 파라미터가 쿼리에 올바르게 적용되어야 한다', async () => {
+      const mockResult = [{ id: 1 }];
+      const testDateRange = 30;
+
+      mockPool.query.mockResolvedValue({
+        rows: mockResult,
+        rowCount: mockResult.length,
+      } as unknown as QueryResult);
+
+      await repo.getLeaderboard('user', 'viewCount', testDateRange, 10);
+
+      expect(mockPool.query).toHaveBeenCalledWith(
+        expect.stringContaining('$1::int'),
+        expect.arrayContaining([testDateRange, expect.anything()]),
+      );
+    });
+
+    it('유효하지 않은 sort 값이 전달되면 기본값(view_diff)을 사용해야 한다', async () => {
+      const mockResult = [{ view_diff: 10 }];
+
+      mockPool.query.mockResolvedValue({
+        rows: mockResult,
+        rowCount: mockResult.length,
+      } as unknown as QueryResult);
+
+      await repo.getLeaderboard('user', 'invalidSort', 30, 10);
+
+      expect(mockPool.query).toHaveBeenCalledWith(expect.stringContaining('view_diff DESC'), expect.anything());
+    });
+
+    it('유효하지 않은 type 값이 전달되면 기본값(user)을 사용해야 한다', async () => {
+      const mockResult = [{ view_diff: 10 }];
+
+      mockPool.query.mockResolvedValue({
+        rows: mockResult,
+        rowCount: mockResult.length,
+      } as unknown as QueryResult);
+
+      const result = await repo.getLeaderboard('invalidType', 'viewCount', 30, 10);
+
+      expect(result).toEqual(mockResult);
+      expect(mockPool.query).toHaveBeenCalledWith(expect.stringContaining('FROM users_user u'), expect.anything());
+    });
+
+    it('데이터가 없는 경우 빈 배열을 반환해야 한다', async () => {
+      mockPool.query.mockResolvedValue({
+        rows: [],
+        rowCount: 0,
+      } as unknown as QueryResult);
+
+      const result = await repo.getLeaderboard('user', 'viewCount', 30, 10);
+
+      expect(result).toEqual([]);
+    });
+
+    it('에러 발생 시 DBError를 던져야 한다', async () => {
+      mockPool.query.mockRejectedValue(new Error('DB connection failed'));
+      await expect(repo.getLeaderboard('post', 'postCount', 30, 10)).rejects.toThrow(DBError);
+    });
+  });
+});