express-middleware.js

import express from 'express';
import formidable from '../src/index.js';

const app = express();

// middlewares that populates req.fields and req.body
const formMiddleWare = (req, res, next) => {
    const form = formidable({});

    form.parse(req, (err, fields, files) => {
      if (err) {
        next(err);
        return;
      }
      req.fields = fields;
      req.files = files;
      next();
    });
};

app.get('/', (req, res) => {
  res.send(`
    <h2>With <code>"express"</code> npm package</h2>
    <form action="/api/upload" enctype="multipart/form-data" method="post">
      <div>Text field title: <input type="text" name="title" /></div>
      <div>File: <input type="file" name="someExpressFiles" multiple="multiple"></div>
      <input type="submit" value="Upload">
    </form>
  `);
});

// use middleware
app.post('/api/upload', formMiddleWare, (req, res, next) => {
    res.json({ 
        fields: req.fields,
        files: req.files,
    });
});

app.listen(3000, () => {
  console.log('Server listening on http://localhost:3000 ...');
});