test: add unit tests for comment liking and enriched comment data

- Added tests for comment liking (`like` and `unlike` methods).
- Improved `findAllByContentId` tests to cover enriched comment data (likes count, isLiked, and user avatar URL resolution).
- Mocked new dependencies (`CommentLikesRepository` and `S3Service`) in `CommentsService` unit tests.

backend/src/comments/comments.service.spec.ts

@@ -1,6 +1,8 @@
 import { ForbiddenException, NotFoundException } from "@nestjs/common";
 import { Test, TestingModule } from "@nestjs/testing";
+import { S3Service } from "../s3/s3.service";
 import { CommentsService } from "./comments.service";
+import { CommentLikesRepository } from "./repositories/comment-likes.repository";
 import { CommentsRepository } from "./repositories/comments.repository";
 
 describe("CommentsService", () => {
@@ -14,11 +16,25 @@ describe("CommentsService", () => {
 		delete: jest.fn(),
 	};
 
+	const mockCommentLikesRepository = {
+		addLike: jest.fn(),
+		removeLike: jest.fn(),
+		countByCommentId: jest.fn(),
+		isLikedByUser: jest.fn(),
+	};
+
+	const mockS3Service = {
+		getPublicUrl: jest.fn(),
+	};
+
 	beforeEach(async () => {
+		jest.clearAllMocks();
 		const module: TestingModule = await Test.createTestingModule({
 			providers: [
 				CommentsService,
 				{ provide: CommentsRepository, useValue: mockCommentsRepository },
+				{ provide: CommentLikesRepository, useValue: mockCommentLikesRepository },
+				{ provide: S3Service, useValue: mockS3Service },
 			],
 		}).compile();
 
@@ -34,7 +50,7 @@ describe("CommentsService", () => {
 		it("should create a comment", async () => {
 			const userId = "user1";
 			const contentId = "content1";
-			const dto = { text: "Nice meme" };
+			const dto = { text: "Nice meme", parentId: undefined };
 			mockCommentsRepository.create.mockResolvedValue({ id: "c1", ...dto });
 
 			const result = await service.create(userId, contentId, dto);
@@ -43,16 +59,25 @@ describe("CommentsService", () => {
 				userId,
 				contentId,
 				text: dto.text,
+				parentId: undefined,
 			});
 		});
 	});
 
 	describe("findAllByContentId", () => {
 		it("should return comments for a content", async () => {
-			mockCommentsRepository.findAllByContentId.mockResolvedValue([{ id: "c1" }]);
+			mockCommentsRepository.findAllByContentId.mockResolvedValue([
-			const result = await service.findAllByContentId("content1");
+				{ id: "c1", user: { avatarUrl: "path" } },
+			]);
+			mockCommentLikesRepository.countByCommentId.mockResolvedValue(5);
+			mockCommentLikesRepository.isLikedByUser.mockResolvedValue(true);
+			mockS3Service.getPublicUrl.mockReturnValue("url");
+
+			const result = await service.findAllByContentId("content1", "u1");
 			expect(result).toHaveLength(1);
-			expect(repository.findAllByContentId).toHaveBeenCalledWith("content1");
+			expect(result[0].likesCount).toBe(5);
+			expect(result[0].isLiked).toBe(true);
+			expect(result[0].user.avatarUrl).toBe("url");
 		});
 	});
 
@@ -81,4 +106,23 @@ describe("CommentsService", () => {
 			);
 		});
 	});
+
+	describe("like", () => {
+		it("should add like", async () => {
+			mockCommentsRepository.findOne.mockResolvedValue({ id: "c1" });
+			await service.like("u1", "c1");
+			expect(mockCommentLikesRepository.addLike).toHaveBeenCalledWith("c1", "u1");
+		});
+	});
+
+	describe("unlike", () => {
+		it("should remove like", async () => {
+			mockCommentsRepository.findOne.mockResolvedValue({ id: "c1" });
+			await service.unlike("u1", "c1");
+			expect(mockCommentLikesRepository.removeLike).toHaveBeenCalledWith(
+				"c1",
+				"u1",
+			);
+		});
+	});
 });