NestJS File Upload (Multer)

import {
  Controller,
  Post,
  UploadedFile,
  UseInterceptors,
} from "@nestjs/common";
import { FileInterceptor } from "@nestjs/platform-express";
import { diskStorage } from "multer";
import { extname } from "node:path";

@Controller("upload")
export class UploadController {
  @Post("avatar")
  @UseInterceptors(
    FileInterceptor("file", {
      storage: diskStorage({
        destination: "./uploads",
        filename: (req, file, cb) => {
          const unique = Date.now() + "-" + Math.round(Math.random() * 1e9);
          cb(null, unique + extname(file.originalname));
        },
      }),
      limits: { fileSize: 5 * 1024 * 1024 }, // 5MB
    }),
  )
  uploadAvatar(
    @UploadedFile() file: Express.Multer.File,
  ) {
    return { message: "Upload সফল", file };
  }
}

import { FilesInterceptor, FileFieldsInterceptor } from "@nestjs/platform-express";

@Post("gallery")
@UseInterceptors(
  FilesInterceptor("files", 10), // ঘরে 10 files
)
uploadGallery(@UploadedFiles() files: Express.Multer.File[]) {
  return { count: files.length };
}

@Post("profile")
@UseInterceptors(
  FileFieldsInterceptor([
    { name: "avatar", maxCount: 1 },
    { name: "cover", maxCount: 1 },
  ]),
)
uploadProfile(@UploadedFiles() files: { avatar: File[]; cover: File[] }) {
  return files;
}

import { BadRequestException } from "@nestjs/common";

const fileFilter = (req: any, file: any, cb: any) => {
  const allowedTypes = ["image/jpeg", "image/png", "image/webp"];

  if (!allowedTypes.includes(file.mimetype)) {
    return cb(new BadRequestException("শুধু image allowed"), false);
  }
  cb(null, true);
};

// Multer options-এ
{
  storage: diskStorage({ ... }),
  fileFilter,
  limits: { fileSize: 5 * 1024 * 1024 },
}

import { NestFactory } from "@nestjs/core";
import { AppModule } from "./app.module";
import { join } from "node:path";

async function bootstrap() {
  const app = await NestFactory.create(AppModule);

  // static serve
  app.useStaticAssets(join(process.cwd(), "uploads"));

  await app.listen(3000);
}
bootstrap();