feat: 첨부파일 관리하는 파일시스템 서비스 및 모듈 생성

BE/src/file/file.module.ts

@@ -0,0 +1,8 @@
+import { FileService } from './file.service';
+import { Module } from '@nestjs/common';
+
+@Module({
+  providers: [FileService],
+  exports: [FileService],
+})
+export class FileModule {}

BE/src/file/file.service.ts

@@ -0,0 +1,35 @@
+import { BadRequestException, Injectable } from '@nestjs/common';
+import { unlink, writeFile } from 'fs/promises';
+import { v4 as uuidv4 } from 'uuid';
+
+@Injectable()
+export class FileService {
+  private readonly basePath = 'static/';
+
+  constructor() {}
+
+  private generateFilename(originalname: string) {
+    const extension = originalname.split('.').pop();
+    const uniqueId = uuidv4();
+    return `${uniqueId}.${extension}`;
+  }
+
+  async upload(path: string, file: Express.Multer.File) {
+    const filePath =
+      this.basePath + path + this.generateFilename(file.originalname);
+    await writeFile(filePath, file.buffer);
+
+    return {
+      imageUrl: filePath,
+      path: filePath,
+    };
+  }
+
+  async getImageUrl(key: string): Promise<string> {
+    return this.basePath + key;
+  }
+
+  async delete(path: string) {
+    await unlink(this.basePath + path);
+  }
+}