feat: add the dislike functionality

package.json

@@ -33,7 +33,6 @@
     "postinstall": "npm install --platform=linux --arch=x64 sharp"
   },
   "dependencies": {
-
     "@google/generative-ai": "^0.22.0",
     "@nestjs/axios": "^4.0.0",
     "@nestjs/bull": "^11.0.2",
@@ -47,7 +46,6 @@
     "@nestjs/swagger": "^11.0.5",
     "@nestjs/typeorm": "^11.0.0",
     "@types/nodemailer": "^6.4.17",
-
     "@types/speakeasy": "^2.0.10",
     "@vitalets/google-translate-api": "^9.2.1",
     "aws-sdk": "^2.1692.0",

src/modules/comments/comments.controller.ts

@@ -26,6 +26,15 @@ export class CommentsController {
     return await this.commentsService.getAComment(id);
   }
 
+  @ApiOperation({ summary: 'Dislike a comment' })
+  @ApiResponse({ status: 200, description: 'Dislike updated successfully' })
+  @ApiResponse({ status: 404, description: 'Comment not found' })
+  @Post(':id/dislike')
+  async dislikeComment(@Param('id') id: string, @Request() req) {
+    const { userId } = req.user;
+    return await this.commentsService.dislikeComment(id, userId);
+  }
+
   @ApiOperation({ summary: 'Delete a comment' })
   @ApiResponse({ status: 200, description: 'The comment has been deleted successfully.' })
   @Delete(':id/delete')

src/modules/comments/comments.service.ts

@@ -74,4 +74,24 @@ export class CommentsService {
       data: { comment },
     };
   }
+
+  async dislikeComment(commentId: string, userId: string): Promise<{ message: string; dislikeCount: number }> {
+    const comment = await this.commentRepository
+      .createQueryBuilder('comment')
+      .where('comment.id = :commentId', { commentId })
+      .getOne();
+
+    if (!comment) {
+      throw new CustomHttpException('Comment not found', HttpStatus.NOT_FOUND);
+    }
+
+    comment.dislikes = Math.max(0, comment.dislikes + 1); // Ensure it doesn't go negative
+
+    await this.commentRepository.save(comment);
+
+    return {
+      message: 'Dislike updated successfully',
+      dislikeCount: comment.dislikes,
+    };
+  }
 }

src/modules/comments/dtos/dislike-comment.dto

@@ -0,0 +1,9 @@
+import { ApiProperty } from '@nestjs/swagger';
+import { IsNotEmpty, IsUUID } from 'class-validator';
+
+export class DislikeCommentDto {
+  @ApiProperty({ description: 'Comment ID to dislike' })
+  @IsNotEmpty()
+  @IsUUID()
+  commentId: string;
+}

src/modules/comments/entities/comments.entity.ts

@@ -19,4 +19,7 @@ export class Comment extends AbstractBaseEntity {
 
   @Column({ nullable: true })
   model_type: string;
+
+  @Column({ type: 'int', default: 0 }) // Add dislikes column
+  dislikes: number;
 }

src/modules/comments/tests/comments.service.spec.ts

@@ -8,11 +8,17 @@ import { User } from '../../user/entities/user.entity';
 import { CustomHttpException } from '@shared/helpers/custom-http-filter';
 import { HttpStatus } from '@nestjs/common';
 
+const mockQueryBuilder = {
+  where: jest.fn().mockReturnThis(),
+  getOne: jest.fn(),
+};
+
 const mockCommentRepository = () => ({
   create: jest.fn(),
   save: jest.fn(),
   findOne: jest.fn(),
   delete: jest.fn(),
+  createQueryBuilder: jest.fn(() => mockQueryBuilder),
 });
 
 const mockUserRepository = () => ({
@@ -131,4 +137,35 @@ describe('CommentsService', () => {
       });
     });
   });
+
+  describe('CommentsService - dislikeComment', () => {
+    it('should throw CustomHttpException if comment is not found', async () => {
+      commentRepository.findOne.mockResolvedValue(null);
+
+      await expect(service.dislikeComment('comment-id', 'user-id')).rejects.toThrow(CustomHttpException);
+      await expect(service.dislikeComment('comment-id', 'user-id')).rejects.toMatchObject({
+        message: 'Comment not found',
+        status: HttpStatus.NOT_FOUND,
+      });
+    });
+
+    it('should increase the dislike count successfully', async () => {
+      const mockComment = { id: 'comment-id', dislikes: 2 };
+
+      // Mock `getOne()` from `createQueryBuilder`
+      mockQueryBuilder.getOne.mockResolvedValue(mockComment);
+      commentRepository.createQueryBuilder.mockReturnValue(mockQueryBuilder);
+
+      commentRepository.save.mockResolvedValue({ ...mockComment, dislikes: 3 });
+
+      const result = await service.dislikeComment('comment-id', 'user-id');
+
+      expect(result).toEqual({
+        message: 'Dislike updated successfully',
+        dislikeCount: 3,
+      });
+
+      expect(commentRepository.save).toHaveBeenCalledWith({ ...mockComment, dislikes: 3 });
+    });
+  });
 });

src/modules/products/tests/mocks/comment.mock.ts

@@ -9,6 +9,7 @@ export const mockComment: Comment = {
   model_type: 'Product',
   user: mockUser,
   product: productMock,
+  dislikes: 0,
   created_at: new Date(),
   updated_at: new Date(),
 };