feat: add post like and unlike

src/posts/posts.controller.ts

@@ -3,6 +3,7 @@ import {
   Controller,
   FileTypeValidator,
   Get,
+  Param,
   ParseFilePipe,
   Post,
   UploadedFile,
@@ -50,4 +51,14 @@ export class PostsController {
   findAll() {
     return this.postsService.findAll();
   }
+
+  @Post(':id/like')
+  like(@User() user: UserPayload, @Param('id') id: string) {
+    return this.postsService.like(+id, user.sub);
+  }
+
+  @Post(':id/unlike')
+  unlike(@User() user: UserPayload, @Param('id') id: string) {
+    return this.postsService.unlike(+id, user.sub);
+  }
 }

src/posts/posts.module.ts

@@ -1,11 +1,12 @@
 import { MikroOrmModule } from '@mikro-orm/nestjs';
 import { Module } from '@nestjs/common';
+import { User } from 'src/users/entities/user.entity';
 import { Post } from './entities/post.entity';
 import { PostsController } from './posts.controller';
 import { PostsService } from './posts.service';
 
 @Module({
-  imports: [MikroOrmModule.forFeature([Post])],
+  imports: [MikroOrmModule.forFeature([Post, User])],
   controllers: [PostsController],
   providers: [PostsService],
 })

src/posts/posts.service.ts

@@ -3,6 +3,7 @@ import { InjectRepository } from '@mikro-orm/nestjs';
 import { EntityManager } from '@mikro-orm/postgresql';
 import { Injectable } from '@nestjs/common';
 import { UserPayload } from 'src/auth/decorators/user.decorator';
+import { User } from 'src/users/entities/user.entity';
 import { CreatePostDto } from './dto/create-post.dto';
 import { Post } from './entities/post.entity';
 
@@ -11,6 +12,8 @@ export class PostsService {
   constructor(
     @InjectRepository(Post)
     private readonly postRepository: EntityRepository<Post>,
+    @InjectRepository(User)
+    private readonly userRepository: EntityRepository<User>,
     private readonly em: EntityManager,
   ) {}
 
@@ -31,4 +34,30 @@ export class PostsService {
   findAll() {
     return this.postRepository.findAll({ populate: ['author'] });
   }
+
+  async like(id: number, userId: number) {
+    const post = await this.postRepository.findOneOrFail(
+      { id },
+      { populate: ['likedBy'] },
+    );
+    const user = await this.userRepository.findOneOrFail({ id: userId });
+
+    if (!post.likedBy.contains(user)) post.likedBy.add(user);
+
+    await this.em.flush();
+    return post;
+  }
+
+  async unlike(id: number, userId: number) {
+    const post = await this.postRepository.findOneOrFail(
+      { id },
+      { populate: ['likedBy'] },
+    );
+    const user = await this.userRepository.findOneOrFail({ id: userId });
+
+    if (post.likedBy.contains(user)) post.likedBy.remove(user);
+
+    await this.em.flush();
+    return post;
+  }
 }