feat(realworld-graphql): add favorite feature (#166)

lamngockhuong · khuongln-1346 · web-flow · commit 5860f288659b · 2025-05-19T18:44:59.000+07:00
Co-authored-by: Lam Ngoc Khuong &lt;lam.ngoc.khuong@sun-asterisk.com&gt;
diff --git a/apps/realworld-api/src/api/article/favorite/favorite.service.ts b/apps/realworld-api/src/api/article/favorite/favorite.service.ts
@@ -48,12 +48,19 @@ export class FavoriteService {
       userId,
     );
 
-    // Remove the user from the list of favorited users
-    article.favoritedBy = article.favoritedBy.filter(
-      (favoritedBy) => favoritedBy.id !== user.id,
+    // Check if the user has already favorited the article
+    const hasFavorited = article.favoritedBy.some(
+      (favoritedBy) => favoritedBy.id === user.id,
     );
 
-    await this.articleRepository.save(article);
+    if (hasFavorited) {
+      // Remove the user from the list of favorited users
+      article.favoritedBy = article.favoritedBy.filter(
+        (favoritedBy) => favoritedBy.id !== user.id,
+      );
+
+      await this.articleRepository.save(article);
+    }
 
     return {
       article: {
diff --git a/apps/realworld-graphql/src/modules/article/article.loader.ts b/apps/realworld-graphql/src/modules/article/article.loader.ts
@@ -23,8 +23,9 @@ export class ArticleDataLoader {
     if (!this.authorLoader) {
       this.authorLoader = new DataLoader<number, UserEntity>(
         async (authorIds: readonly number[]) => {
-          const authors = await this.userRepository.findBy({
-            id: In([...authorIds]),
+          const authors = await this.userRepository.find({
+            where: { id: In([...authorIds]) },
+            relations: ['followers'],
           });
           return authorIds.map((id) =>
             authors.find((author) => author.id === id),
diff --git a/apps/realworld-graphql/src/modules/article/article.module.ts b/apps/realworld-graphql/src/modules/article/article.module.ts
@@ -4,9 +4,13 @@ import { ArticleEntity, TagEntity, UserEntity } from '@repo/postgresql-typeorm';
 import { ArticleDataLoader } from './article.loader';
 import { ArticleResolver } from './article.resolver';
 import { ArticleService } from './article.service';
+import { FavoriteModule } from './favorite/favorite.module';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([ArticleEntity, TagEntity, UserEntity])],
+  imports: [
+    FavoriteModule,
+    TypeOrmModule.forFeature([ArticleEntity, TagEntity, UserEntity]),
+  ],
   providers: [ArticleResolver, ArticleService, ArticleDataLoader],
   exports: [ArticleService],
 })
diff --git a/apps/realworld-graphql/src/modules/article/article.resolver.ts b/apps/realworld-graphql/src/modules/article/article.resolver.ts
@@ -1,3 +1,4 @@
+import { Logger } from '@nestjs/common';
 import {
   Args,
   Info,
@@ -21,6 +22,7 @@ import { Article } from './model/article.model';
 
 @Resolver(() => Article)
 export class ArticleResolver {
+  private readonly logger = new Logger(ArticleResolver.name);
   constructor(
     private readonly articleService: ArticleService,
     private readonly dataLoader: ArticleDataLoader,
@@ -35,6 +37,7 @@ export class ArticleResolver {
     @Args() { slug }: SlugArgs,
     @Info() info: GraphQLResolveInfo,
   ): Promise<Article> {
+    this.logger.log('Getting article', slug);
     const requestedFields = getFieldNames(info);
 
     const shouldEagerLoad = ['author', 'favorited', 'favoritesCount'].every(
@@ -90,16 +93,19 @@ export class ArticleResolver {
   }
 
   @ResolveField(() => Profile)
-  async author(@Parent() article: Article): Promise<Profile> {
+  async author(
+    @CurrentUser('id') userId: number,
+    @Parent() article: Article,
+  ): Promise<Profile> {
     if (article.author) return article.author;
+    this.logger.log('Getting author for article', article.id);
     const author = await this.dataLoader
       .getAuthorLoader()
       .load(article.authorId);
     const profile = author.toDto(Profile);
     profile.following =
-      author?.following?.some(
-        (followee) => followee.followeeId === article?.author?.id,
-      ) || false;
+      author?.followers?.some((follower) => follower.followerId === userId) ||
+      false;
     return profile;
   }
 
@@ -109,6 +115,7 @@ export class ArticleResolver {
     @CurrentUser('id') userId: number,
   ) {
     if (article.favorited !== undefined) return article.favorited;
+    this.logger.log('Getting favorited for article', article.id);
     const { favorited } = await this.dataLoader
       .getFavoritesLoader(userId)
       .load(article.id);
@@ -121,6 +128,7 @@ export class ArticleResolver {
     @CurrentUser('id') userId: number,
   ) {
     if (article.favoritesCount !== undefined) return article.favoritesCount;
+    this.logger.log('Getting favorites count for article', article.id);
     const { count } = await this.dataLoader
       .getFavoritesLoader(userId)
       .load(article.id);
diff --git a/apps/realworld-graphql/src/modules/article/article.service.ts b/apps/realworld-graphql/src/modules/article/article.service.ts
@@ -99,7 +99,7 @@ export class ArticleService {
     if (shouldEagerLoad) {
       article = await this.articleRepository.findOne({
         where: { id: savedArticle.id },
-        relations: ['author', 'author.following', 'tags', 'favoritedBy'],
+        relations: ['author', 'author.followers', 'tags', 'favoritedBy'],
       });
     } else {
       article = await this.articleRepository.findOne({
@@ -116,8 +116,8 @@ export class ArticleService {
           username: article.author.username,
           bio: article.author.bio,
           image: article.author.image,
-          following: article.author.following.some(
-            (follow) => follow.followeeId === userId,
+          following: article.author.followers.some(
+            (follower) => follower.followerId === userId,
           ),
         },
         favorited: article.favoritedBy.some((user) => user.id === userId),
@@ -169,7 +169,7 @@ export class ArticleService {
     if (shouldEagerLoad) {
       newArticle = await this.articleRepository.findOne({
         where: { id: savedArticle.id },
-        relations: ['author', 'author.following', 'tags', 'favoritedBy'],
+        relations: ['author', 'author.followers', 'tags', 'favoritedBy'],
       });
     } else {
       newArticle = await this.articleRepository.findOne({
@@ -186,8 +186,8 @@ export class ArticleService {
           username: newArticle.author.username,
           bio: newArticle.author.bio,
           image: newArticle.author.image,
-          following: newArticle.author.following.some(
-            (follow) => follow.followeeId === userId,
+          following: newArticle.author.followers.some(
+            (follower) => follower.followerId === userId,
           ),
         },
         favorited: newArticle.favoritedBy.some((user) => user.id === userId),
diff --git a/apps/realworld-graphql/src/modules/article/favorite/favorite.module.ts b/apps/realworld-graphql/src/modules/article/favorite/favorite.module.ts
@@ -1,8 +1,11 @@
 import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { ArticleEntity, UserEntity } from '@repo/postgresql-typeorm';
+import { FavoriteResolver } from './favorite.resolver';
+import { FavoriteService } from './favorite.service';
 
 @Module({
-  imports: [],
-  controllers: [],
-  providers: [],
+  imports: [TypeOrmModule.forFeature([ArticleEntity, UserEntity])],
+  providers: [FavoriteResolver, FavoriteService],
 })
 export class FavoriteModule {}
diff --git a/apps/realworld-graphql/src/modules/article/favorite/favorite.resolver.ts b/apps/realworld-graphql/src/modules/article/favorite/favorite.resolver.ts
@@ -0,0 +1,47 @@
+import { Args, Info, Mutation, Resolver } from '@nestjs/graphql';
+import { CurrentUser } from '@repo/graphql/decorators/current-user.decorator';
+import { getFieldNames } from '@repo/graphql/utils/graphql-fields.util';
+import type { GraphQLResolveInfo } from 'graphql';
+import { Article } from '../model/article.model';
+import { FavoriteService } from './favorite.service';
+
+@Resolver(() => Article)
+export class FavoriteResolver {
+  constructor(private readonly favoriteService: FavoriteService) {}
+
+  @Mutation(() => Article, {
+    name: 'favoriteArticle',
+    description: 'Favorite an article',
+  })
+  async create(
+    @CurrentUser('id') userId: number,
+    @Args('slug') slug: string,
+    @Info() info: GraphQLResolveInfo,
+  ): Promise<Article> {
+    const requestedFields = getFieldNames(info);
+
+    const shouldEagerLoad = ['favorited', 'favoritesCount'].every((field) =>
+      requestedFields.includes(field),
+    );
+
+    return await this.favoriteService.create(slug, userId, shouldEagerLoad);
+  }
+
+  @Mutation(() => Article, {
+    name: 'unfavoriteArticle',
+    description: 'Unfavorite an article',
+  })
+  async delete(
+    @CurrentUser('id') userId: number,
+    @Args('slug') slug: string,
+    @Info() info: GraphQLResolveInfo,
+  ): Promise<Article> {
+    const requestedFields = getFieldNames(info);
+
+    const shouldEagerLoad = ['favorited', 'favoritesCount'].every((field) =>
+      requestedFields.includes(field),
+    );
+
+    return await this.favoriteService.delete(slug, userId, shouldEagerLoad);
+  }
+}
diff --git a/apps/realworld-graphql/src/modules/article/favorite/favorite.service.ts b/apps/realworld-graphql/src/modules/article/favorite/favorite.service.ts
@@ -0,0 +1,139 @@
+import { ErrorCode } from '@/constants/error-code.constant';
+import { Injectable, Logger } from '@nestjs/common';
+import { InjectRepository } from '@nestjs/typeorm';
+import { ValidationException } from '@repo/graphql/exceptions/validation.exception';
+import { ArticleEntity, UserEntity } from '@repo/postgresql-typeorm';
+import { Repository } from 'typeorm';
+import { Article } from '../model/article.model';
+@Injectable()
+export class FavoriteService {
+  private readonly logger = new Logger(FavoriteService.name);
+  constructor(
+    @InjectRepository(ArticleEntity)
+    private readonly articleRepository: Repository<ArticleEntity>,
+    @InjectRepository(UserEntity)
+    private readonly userRepository: Repository<UserEntity>,
+  ) {}
+
+  async create(
+    slug: string,
+    userId: number,
+    shouldEagerLoad: boolean,
+  ): Promise<Article> {
+    const { user, article } = await this.validateAndGetUserArticle(
+      slug,
+      userId,
+      shouldEagerLoad,
+    );
+
+    // Check if the user has already favorited the article
+    const hasFavorited = article.favoritedBy.some(
+      (favoritedBy) => favoritedBy.id === user.id,
+    );
+
+    if (!hasFavorited) {
+      article.favoritedBy.push(user);
+      await this.articleRepository.save(article);
+
+      // If you want to use the raw query, you can use the following code
+      // await this.dataSource
+      //   .createQueryBuilder()
+      //   .insert()
+      //   .into('user_favorites')
+      //   .values({
+      //     article_id: article.id,
+      //     user_id: user.id,
+      //   })
+      //   .execute();
+    }
+
+    return {
+      ...article.toDto(Article),
+      tagList: article?.tags?.map((tag) => tag.name).reverse() || [],
+      favorited: true,
+      favoritesCount: article.favoritedBy.length,
+      ...(shouldEagerLoad && {
+        author: {
+          username: article.author.username,
+          bio: article.author.bio,
+          image: article.author.image,
+          following: article.author.followers.some(
+            (follower) => follower.followerId === userId,
+          ),
+        },
+      }),
+    };
+  }
+
+  async delete(
+    slug: string,
+    userId: number,
+    shouldEagerLoad: boolean,
+  ): Promise<Article> {
+    this.logger.log('Deleting favorite for article', slug);
+    const { user, article } = await this.validateAndGetUserArticle(
+      slug,
+      userId,
+      shouldEagerLoad,
+    );
+
+    // Check if the user has already favorited the article
+    const hasFavorited = article.favoritedBy.some(
+      (favoritedBy) => favoritedBy.id === user.id,
+    );
+
+    if (hasFavorited) {
+      // Remove the user from the list of favorited users
+      article.favoritedBy = article.favoritedBy.filter(
+        (favoritedBy) => favoritedBy.id !== user.id,
+      );
+
+      await this.articleRepository.save(article);
+    }
+
+    return {
+      ...article.toDto(Article),
+      tagList: article?.tags?.map((tag) => tag.name).reverse() || [],
+      favorited: false,
+      favoritesCount: article.favoritedBy.length,
+      ...(shouldEagerLoad && {
+        author: {
+          username: article.author.username,
+          bio: article.author.bio,
+          image: article.author.image,
+          following: article.author.followers.some(
+            (follower) => follower.followerId === userId,
+          ),
+        },
+      }),
+    };
+  }
+
+  private async validateAndGetUserArticle(
+    slug: string,
+    userId: number,
+    shouldEagerLoad: boolean,
+  ): Promise<{ user: UserEntity; article: ArticleEntity }> {
+    const user = await this.userRepository.findOneOrFail({
+      where: { id: userId },
+    });
+    let article: ArticleEntity;
+    if (shouldEagerLoad) {
+      article = await this.articleRepository.findOne({
+        where: { slug },
+        relations: ['author', 'author.followers', 'tags', 'favoritedBy'],
+      });
+    } else {
+      article = await this.articleRepository.findOne({
+        where: { slug },
+        relations: ['tags', 'favoritedBy'],
+      });
+    }
+
+    if (!article) {
+      throw new ValidationException(ErrorCode.E201);
+    }
+
+    return { user, article };
+  }
+}
diff --git a/apps/realworld-graphql/src/schema.gql b/apps/realworld-graphql/src/schema.gql
@@ -57,6 +57,9 @@ type Mutation {
   createUser(input: CreateUserInput!): User!
   deleteArticle(slug: String!): Boolean!
 
+  """Favorite an article"""
+  favoriteArticle(slug: String!): Article!
+
   """Follow User"""
   followUser(
     """Username of the profile"""
@@ -66,6 +69,9 @@ type Mutation {
   """Sign in"""
   login(input: LoginInput!): User!
 
+  """Unfavorite an article"""
+  unfavoriteArticle(slug: String!): Article!
+
   """Unfollow User"""
   unfollowUser(
     """Username of the profile"""
diff --git a/tools/test/realworld-graphql.postman_collection.json b/tools/test/realworld-graphql.postman_collection.json
