refactor: ♻️ unionType -> throw Exception

- #406

Author: niamu01

app/src/follow/follow.resolver.ts

@@ -1,12 +1,12 @@
-import { UseFilters, UseGuards } from '@nestjs/common';
+import { NotFoundException, UseFilters, UseGuards } from '@nestjs/common';
 import { Args, Mutation, Query, Resolver, Subscription } from '@nestjs/graphql';
 import { PubSub } from 'graphql-subscriptions';
 import { MyUserId } from 'src/auth/myContext';
 import { StatAuthGuard } from 'src/auth/statAuthGuard';
 import { HttpExceptionFilter } from 'src/http-exception.filter';
 import { FollowListPaginatedArgs } from './dto/follow.dto.getFollowList';
 import { FollowService } from './follow.service';
-import { FollowListPaginated, FollowResult } from './model/follow.model';
+import { FollowListPaginated, FollowSuccess } from './model/follow.model';
 
 const pubSub = new PubSub();
 
@@ -15,44 +15,46 @@ const pubSub = new PubSub();
 export class FollowResolver {
   constructor(private readonly followService: FollowService) {}
 
-  @Subscription((_returns) => FollowResult, {
-    name: 'followUpdated',
-    filter: (payload, _variables) => {
-      return payload.followUpdated.message === 'OK';
-    },
-  })
+  @Subscription((_returns) => FollowSuccess, { name: 'followUpdated' })
   followUpdated() {
     return pubSub.asyncIterator('followUpdated');
   }
 
   @UseGuards(StatAuthGuard)
-  @Mutation((_returns) => FollowResult)
+  @Mutation((_returns) => FollowSuccess)
   async followUser(
     @MyUserId() userId: number,
     @Args('target') target: string,
-  ): Promise<typeof FollowResult> {
-    const followResult = await this.followService.followUser(userId, target);
+  ): Promise<FollowSuccess> {
+    try {
+      const followResult = await this.followService.followUser(userId, target);
 
-    if (followResult.message === 'OK') {
       await pubSub.publish('followUpdated', { followUpdated: followResult });
-    }
 
-    return followResult;
+      return followResult;
+    } catch (e) {
+      throw new NotFoundException();
+    }
   }
 
   @UseGuards(StatAuthGuard)
-  @Mutation((_returns) => FollowResult)
+  @Mutation((_returns) => FollowSuccess)
   async unfollowUser(
     @MyUserId() userId: number,
     @Args('target') target: string,
-  ): Promise<typeof FollowResult> {
-    const followResult = await this.followService.unfollowUser(userId, target);
+  ): Promise<FollowSuccess> {
+    try {
+      const followResult = await this.followService.unfollowUser(
+        userId,
+        target,
+      );
 
-    if (followResult.message === 'OK') {
       await pubSub.publish('followUpdated', { followUpdated: followResult });
-    }
 
-    return followResult;
+      return followResult;
+    } catch (e) {
+      throw new NotFoundException();
+    }
   }
 
   @UseGuards(StatAuthGuard)

app/src/follow/follow.service.ts

@@ -8,10 +8,6 @@ import {
   findAllAndLean,
   findOneAndLean,
 } from 'src/database/mongoose/database.mongoose.query';
-import {
-  CursorExtractor,
-  FieldExtractor,
-} from 'src/pagination/cursor/pagination.cursor.service';
 import { PaginationIndexService } from 'src/pagination/index/pagination.index.service';
 import { CursusUserService } from '../api/cursusUser/cursusUser.service';
 import { follow } from './db/follow.database.schema';
@@ -22,7 +18,7 @@ import {
 import type {
   FollowList,
   FollowListPaginated,
-  FollowResult,
+  FollowSuccess,
 } from './model/follow.model';
 
 type FollowListCursorField = [number, string];
@@ -56,10 +52,7 @@ export class FollowService {
     return id;
   }
 
-  async followUser(
-    userId: number,
-    target: string,
-  ): Promise<typeof FollowResult> {
+  async followUser(userId: number, target: string): Promise<FollowSuccess> {
     const following = await this.cursusUserService.getuserIdByLogin(target);
 
     const alreadyFollow = await this.followModel.findOne(
@@ -71,7 +64,7 @@ export class FollowService {
     );
 
     if (!following || userId === following || alreadyFollow) {
-      return { message: 'fail' };
+      throw new NotFoundException();
     }
 
     const result = await this.followModel.create({
@@ -81,20 +74,16 @@ export class FollowService {
     });
 
     return {
-      message: 'OK',
       userId: result.userId,
       followId: result.followId,
     };
   }
 
-  async unfollowUser(
-    userId: number,
-    target: string,
-  ): Promise<typeof FollowResult> {
+  async unfollowUser(userId: number, target: string): Promise<FollowSuccess> {
     const following = await this.cursusUserService.getuserIdByLogin(target);
 
     if (!following || userId === following) {
-      return { message: 'fail' };
+      throw new NotFoundException();
     }
 
     const deletedCount = await this.followModel
@@ -106,13 +95,12 @@ export class FollowService {
 
     if (deletedCount === 1) {
       return {
-        message: 'OK',
         userId: userId,
         followId: following,
       };
     }
 
-    return { message: 'fail' };
+    throw new NotFoundException();
   }
 
   async followerList(

app/src/follow/model/follow.model.ts

@@ -1,4 +1,4 @@
-import { Field, ObjectType, createUnionType } from '@nestjs/graphql';
+import { Field, ObjectType } from '@nestjs/graphql';
 import { UserPreview } from 'src/common/models/common.user.model';
 import { IndexPaginated } from 'src/pagination/index/models/pagination.index.model';
 
@@ -23,33 +23,11 @@ export class FollowListWithCount {
   count: number;
 }
 
-@ObjectType()
-export class FollowFail {
-  @Field()
-  message: 'fail';
-}
-
 @ObjectType()
 export class FollowSuccess {
-  @Field()
-  message: 'OK';
-
   @Field()
   userId: number;
 
   @Field()
   followId: number;
 }
-
-export const FollowResult = createUnionType({
-  name: 'FollowResult',
-  types: () => [FollowSuccess, FollowFail] as const,
-  resolveType(value) {
-    switch (value.message) {
-      case 'OK':
-        return FollowSuccess;
-      case 'fail':
-        return FollowFail;
-    }
-  },
-});

app/src/schema.gql

@@ -71,6 +71,11 @@ type FollowListPaginated {
   pageNumber: Int!
 }
 
+type FollowSuccess {
+  userId: Int!
+  followId: Int!
+}
+
 type LinkableAccount {
   platform: String!
   id: String!
@@ -656,8 +661,8 @@ type Mutation {
   refreshToken(refreshToken: String!): LoginSuccess!
   logout: Int!
   deleteAccount: Int!
-  followUser(target: String!): FollowResult!
-  unfollowUser(target: String!): FollowResult!
+  followUser(target: String!): FollowSuccess!
+  unfollowUser(target: String!): FollowSuccess!
 }
 
 union LoginResult = LoginSuccess | LoginNotLinked
@@ -671,18 +676,6 @@ input GoogleLoginInput {
   credential: String!
 }
 
-union FollowResult = FollowSuccess | FollowFail
-
-type FollowSuccess {
-  message: String!
-  userId: Int!
-  followId: Int!
-}
-
-type FollowFail {
-  message: String!
-}
-
 type Subscription {
-  followUpdated: FollowResult!
+  followUpdated: FollowSuccess!
 }