refactor: ♻️ aggregate -> find~~ 로 변경, 필요한 데이터만 받도록 select 사용

- #406

Author: niamu01

app/src/follow/follow.service.ts

@@ -4,7 +4,9 @@ import { FilterQuery, Model, SortOrder } from 'mongoose';
 import { UserPreview } from 'src/common/models/common.user.model';
 import {
   QueryArgs,
+  QueryOneArgs,
   findAllAndLean,
+  findOneAndLean,
 } from 'src/database/mongoose/database.mongoose.query';
 import {
   CursorExtractor,
@@ -34,6 +36,12 @@ export class FollowService {
     private readonly paginationCursorService: PaginationCursorService,
   ) {}
 
+  async findOneAndLean(
+    queryOneArgs?: QueryOneArgs<follow>,
+  ): Promise<follow | null> {
+    return await findOneAndLean(this.followModel, queryOneArgs);
+  }
+
   async findAllAndLean(queryArgs?: QueryArgs<follow>): Promise<follow[]> {
     return await findAllAndLean(this.followModel, queryArgs);
   }
@@ -118,10 +126,12 @@ export class FollowService {
       aggregate.match(filter);
     }
 
-    const follower = await aggregate
-      .match({ followId: targetId })
-      .sort(followSort(sortOrder))
-      .limit(limit);
+    const follower: Pick<follow, 'userId'>[] = await this.findAllAndLean({
+      filter: { followId: targetId },
+      select: { _id: 0, userId: 1 },
+      sort: followSort(sortOrder),
+      limit,
+    });
 
     const followerUserPreview = await Promise.all(
       follower.map(async (follower) => {
@@ -156,10 +166,14 @@ export class FollowService {
       const [id, _login]: FollowListCursorField =
         this.paginationCursorService.toFields(after, fieldExtractor);
 
-      const [followAt] = await aggregate.match({
-        userId: id,
-        followId: targetId,
-      });
+      const followAt: Pick<follow, 'followAt'> | null =
+        await this.findOneAndLean({
+          filter: {
+            userId: id,
+            followId: targetId,
+          },
+          select: { _id: 0, followAt: 1 },
+        });
 
       if (!followAt) {
         return this.generateEmptyPage();
@@ -206,10 +220,12 @@ export class FollowService {
       aggregate.match(filter);
     }
 
-    const following = await aggregate
-      .match({ userId: targetId })
-      .sort(followSort(sortOrder))
-      .limit(limit);
+    const following: Pick<follow, 'followId'>[] = await this.findAllAndLean({
+      filter: { userId: targetId },
+      select: { _id: 0, followId: 1 },
+      sort: followSort(sortOrder),
+      limit,
+    });
 
     const followingUserPreview = await Promise.all(
       following.map(async (following) => {
@@ -244,10 +260,14 @@ export class FollowService {
       const [id, _login]: FollowListCursorField =
         this.paginationCursorService.toFields(after, fieldExtractor);
 
-      const [followAt] = await aggregate.match({
-        userId: targetId,
-        followId: id,
-      });
+      const followAt: Pick<follow, 'followAt'> | null =
+        await this.findOneAndLean({
+          filter: {
+            userId: targetId,
+            followId: id,
+          },
+          select: { _id: 0, followAt: 1 },
+        });
 
       if (!followAt) {
         return this.generateEmptyPage();