File Upload con Express

npm install express express-fileupload dotenv

// models/Server.js (fragmento)
import fileUpload from 'express-fileupload';

middlewares() {
  this.app.use(express.json());

  this.app.use(fileUpload({
    limits: { fileSize: 5_000_000 }, // 5 MB en bytes
    abortOnLimit: true,
    responseOnLimit: 'El archivo supera el límite de 5 MB'
  }));

  // Servir archivos subidos como estáticos
  const uploadsDir = path.join(__dirname, '../uploads');
  this.app.use('/uploads', express.static(uploadsDir));
}

models/
  Server.js
controllers/
  uploads.controller.js
services/
  uploads.service.js
routes/
  uploads.routes.js
middlewares/
  requestInfo.js
  errorHandler.js
  notFound.js
utils/
  ApiError.js
  apiResponse.js
uploads/              ← generada automáticamente si no existe
public/
  index.html          ← formulario HTML para probar la subida

// services/uploads.service.js
import fs   from 'fs';
import path from 'path';
import { fileURLToPath } from 'url';
import { ApiError } from '../utils/ApiError.js';

const __dirname   = path.dirname(fileURLToPath(import.meta.url));
const uploadsDir  = path.join(path.dirname(__dirname), 'uploads');

// Crear la carpeta si no existe
if (!fs.existsSync(uploadsDir)) {
  fs.mkdirSync(uploadsDir, { recursive: true });
}

const ALLOWED_EXTENSIONS = ['.pdf', '.doc', '.txt', '.xls', '.xlsx',
                             '.jpg', '.jpeg', '.png', '.gif'];

export const uploadFileService = async (file) => {
  if (!file) throw new ApiError(400, 'No se recibió ningún archivo');

  const ext = path.extname(file.name).toLowerCase();
  if (!ALLOWED_EXTENSIONS.includes(ext)) {
    throw new ApiError(400, `Extensión no permitida. Permitidas: ${ALLOWED_EXTENSIONS.join(', ')}`);
  }

  // Nombre único: timestamp + sufijo aleatorio + nombre original
  const timestamp    = Date.now();
  const randomSuffix = Math.random().toString(36).slice(2, 9);
  const storedName   = `${timestamp}-${randomSuffix}-${file.name}`;
  const destPath     = path.join(uploadsDir, storedName);

  await file.mv(destPath); // mueve el archivo desde memoria al disco

  return {
    id:           timestamp,
    filename:     file.name,
    storedName,
    size:         file.size,
    mimetype:     file.mimetype,
    uploadedAt:   new Date().toISOString(),
    url:          `/uploads/${storedName}`
  };
};

export const listFilesService = () => {
  const files = fs.readdirSync(uploadsDir);
  return files.map(name => ({
    name,
    size: fs.statSync(path.join(uploadsDir, name)).size,
    url:  `/uploads/${name}`
  }));
};

export const deleteFileService = (filename) => {
  const filePath = path.join(uploadsDir, filename);
  if (!fs.existsSync(filePath)) {
    throw new ApiError(404, `Archivo "${filename}" no encontrado`);
  }
  fs.unlinkSync(filePath);
  return { deleted: filename };
};

// controllers/uploads.controller.js
import path             from 'path';
import { uploadFileService, listFilesService, deleteFileService } from '../services/uploads.service.js';
import { sendResponse } from '../utils/apiResponse.js';
import { ApiError }     from '../utils/ApiError.js';

export const uploadFileController = async (req, res, next) => {
  try {
    if (!req.files || Object.keys(req.files).length === 0) {
      throw new ApiError(400, 'No se envió ningún archivo');
    }
    const file   = req.files.file; // campo "file" del formulario
    const result = await uploadFileService(file);
    sendResponse(res, 201, result, 'Archivo subido correctamente');
  } catch (e) { next(e); }
};

export const listFilesController = async (req, res, next) => {
  try {
    const files = listFilesService();
    sendResponse(res, 200, files, 'Archivos listados correctamente');
  } catch (e) { next(e); }
};

export const deleteFileController = async (req, res, next) => {
  try {
    const filename = path.basename(req.params.filename); // sanitización
    const result   = await deleteFileService(filename);
    sendResponse(res, 200, result, 'Archivo eliminado correctamente');
  } catch (e) { next(e); }
};

// routes/uploads.routes.js
import { Router } from 'express';
import { uploadFileController, listFilesController, deleteFileController } from '../controllers/uploads.controller.js';

const router = Router();

router.post('/',             uploadFileController);  // sube un archivo
router.get('/',              listFilesController);   // lista los archivos
router.delete('/:filename',  deleteFileController);  // elimina un archivo

export default router;

// models/Server.js (routes)
routes() {
  this.app.use('/api/v1/uploads', uploadsRoutes);
  this.app.use(notFoundMiddleware);
  this.app.use(errorHandlerMiddleware);
}

<!-- public/index.html -->
<form action="/api/v1/uploads" method="POST" enctype="multipart/form-data">
  <input type="file" name="file" />
  <button type="submit">Subir archivo</button>
</form>