adopt-a-street/backend/__tests__/models/Comment.test.js

const Comment = require('../../models/Comment');

describe('Comment Model', () => {
  beforeEach(() => {
    jest.clearAllMocks();
    // Reset all mocks to ensure clean state
    global.mockCouchdbService.createDocument.mockReset();
    global.mockCouchdbService.findDocumentById.mockReset();
    global.mockCouchdbService.updateDocument.mockReset();
    global.mockCouchdbService.findByType.mockReset();
    global.mockCouchdbService.getById.mockReset();
    global.mockCouchdbService.find.mockReset();
    global.mockCouchdbService.findUserById.mockReset();
    global.mockCouchdbService.update.mockReset();
    global.mockCouchdbService.deleteDocument.mockReset();
  });

  describe('Schema Validation', () => {
    it('should create a valid comment', async () => {
      const commentData = {
        user: { userId: 'user_123' },
        post: { postId: 'post_123' },
        content: 'This is a great post!',
      };

      const mockUser = {
        _id: 'user_123',
        name: 'Test User',
        profilePicture: ''
      };

      const mockPost = {
        _id: 'post_123',
        content: 'Test post content',
        user: { userId: 'user_123' },
        commentsCount: 0
      };

      const mockCreated = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        user: {
          userId: 'user_123',
          name: 'Test User',
          profilePicture: ''
        },
        post: {
          postId: 'post_123',
          content: 'Test post content',
          userId: 'user_123'
        },
        content: 'This is a great post!',
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      global.mockCouchdbService.findUserById.mockResolvedValue(mockUser);
      global.mockCouchdbService.getById.mockResolvedValue(mockPost);
      global.mockCouchdbService.createDocument.mockResolvedValue(mockCreated);

      const comment = await Comment.create(commentData);

      expect(comment._id).toBeDefined();
      expect(comment.user.userId).toBe('user_123');
      expect(comment.post.postId).toBe('post_123');
      expect(comment.content).toBe('This is a great post!');
    });

    it('should require post field', async () => {
      const commentData = {
        author: 'user_123',
        content: 'Comment without post',
      };

      expect(() => new Comment(commentData)).toThrow();
    });

    it('should require author field', async () => {
      const commentData = {
        post: 'post_123',
        content: 'Comment without author',
      };

      expect(() => new Comment(commentData)).toThrow();
    });

    it('should require content field', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
      };

      expect(() => new Comment(commentData)).toThrow();
    });
  });

  describe('Content Validation', () => {
    it('should trim content', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: '  This comment has spaces  ',
      };

      const mockCreated = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        content: 'This comment has spaces',
        likes: [],
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);

      const comment = await Comment.create(commentData);

      expect(comment.content).toBe('This comment has spaces');
    });

    it('should allow long comments', async () => {
      const longContent = 'a'.repeat(1001); // Long comment

      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: longContent,
      };

      const mockCreated = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        likes: [],
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);

      const comment = await Comment.create(commentData);

      expect(comment.content).toBe(longContent);
    });

    it('should reject empty content after trimming', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: '   ', // Only spaces
      };

      expect(() => new Comment(commentData)).toThrow();
    });
  });

  describe('Likes', () => {
    it('should start with empty likes array', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: 'Comment with no likes',
      };

      const mockCreated = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        likes: [],
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);

      const comment = await Comment.create(commentData);

      expect(comment.likes).toEqual([]);
      expect(comment.likes).toHaveLength(0);
    });

    it('should allow adding likes', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: 'Comment to be liked',
        likes: ['user_456']
      };

      const mockCreated = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);

      const comment = await Comment.create(commentData);

      expect(comment.likes).toHaveLength(1);
      expect(comment.likes[0]).toBe('user_456');
    });

    it('should allow multiple likes', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: 'Popular comment',
        likes: ['user_456', 'user_789', 'user_101']
      };

      const mockCreated = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);

      const comment = await Comment.create(commentData);

      expect(comment.likes).toHaveLength(3);
      expect(comment.likes).toContain('user_456');
      expect(comment.likes).toContain('user_789');
      expect(comment.likes).toContain('user_101');
    });

    it('should allow adding likes after creation', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: 'Comment to be liked later',
      };

      const mockComment = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        likes: [],
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.findDocumentById.mockResolvedValue(mockComment);
      mockCouchdbService.updateDocument.mockResolvedValue({
        ...mockComment,
        likes: ['user_456'],
        _rev: '2-def'
      });

      const comment = await Comment.findById('comment_123');
      comment.likes.push('user_456');
      await comment.save();

      expect(comment.likes).toHaveLength(1);
      expect(comment.likes[0]).toBe('user_456');
    });
  });

  describe('Relationships', () => {
    it('should reference post ID', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: 'Comment on specific post',
      };

      const mockCreated = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        likes: [],
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);

      const comment = await Comment.create(commentData);

      expect(comment.post).toBe('post_123');
    });

    it('should reference author ID', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: 'Comment by specific user',
      };

      const mockCreated = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        likes: [],
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);

      const comment = await Comment.create(commentData);

      expect(comment.author).toBe('user_123');
    });
  });

  describe('Timestamps', () => {
    it('should automatically set createdAt and updatedAt', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: 'Timestamp test comment',
      };

      const mockCreated = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        likes: [],
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);

      const comment = await Comment.create(commentData);

      expect(comment.createdAt).toBeDefined();
      expect(comment.updatedAt).toBeDefined();
      expect(typeof comment.createdAt).toBe('string');
      expect(typeof comment.updatedAt).toBe('string');
    });

    it('should update updatedAt on modification', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: 'Update test comment',
      };

      const mockComment = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        likes: [],
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.findDocumentById.mockResolvedValue(mockComment);
      mockCouchdbService.updateDocument.mockResolvedValue({
        ...mockComment,
        content: 'Updated comment content',
        _rev: '2-def',
        updatedAt: '2023-01-01T00:00:01.000Z'
      });

      const comment = await Comment.findById('comment_123');
      const originalUpdatedAt = comment.updatedAt;

      comment.content = 'Updated comment content';
      await comment.save();

      expect(comment.updatedAt).not.toBe(originalUpdatedAt);
    });
  });

  describe('Content Edge Cases', () => {
    it('should handle special characters in content', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: 'This comment has émojis 🎉 and spëcial charactërs!',
      };

      const mockCreated = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        likes: [],
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);

      const comment = await Comment.create(commentData);

      expect(comment.content).toBe('This comment has émojis 🎉 and spëcial charactërs!');
    });

    it('should handle newlines in content', async () => {
      const commentData = {
        post: 'post_123',
        author: 'user_123',
        content: 'This comment\nhas\nmultiple\nlines',
      };

      const mockCreated = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        ...commentData,
        likes: [],
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.createDocument.mockResolvedValue(mockCreated);

      const comment = await Comment.create(commentData);

      expect(comment.content).toBe('This comment\nhas\nmultiple\nlines');
    });
  });

  describe('Static Methods', () => {
    it('should find comment by ID', async () => {
      const mockComment = {
        _id: 'comment_123',
        _rev: '1-abc',
        type: 'comment',
        post: 'post_123',
        author: 'user_123',
        content: 'Test comment',
        likes: [],
        createdAt: '2023-01-01T00:00:00.000Z',
        updatedAt: '2023-01-01T00:00:00.000Z'
      };

      mockCouchdbService.findDocumentById.mockResolvedValue(mockComment);

      const comment = await Comment.findById('comment_123');
      expect(comment).toBeDefined();
      expect(comment._id).toBe('comment_123');
      expect(comment.content).toBe('Test comment');
    });

    it('should return null when comment not found', async () => {
      mockCouchdbService.findDocumentById.mockResolvedValue(null);

      const comment = await Comment.findById('nonexistent');
      expect(comment).toBeNull();
    });
  });
});