Enhanced Multer File Uploader

A simplified, enhanced wrapper around Multer for Node.js. This package provides easy configuration for file uploads with built-in validation, size limits, and flexible file naming strategies.

Features

• 🚀 Zero Config Defaults: Works out of the box with sensible defaults (5MB limit, image validation).
• 📂 Auto Directory Creation: Automatically creates the upload directory if it doesn't exist.
• 🛡️ Easy Validation: Simple array-based file type validation (extensions or mimetypes).
• 📏 Size Limits: Set file size limits in MB directly.
• 📝 Naming Strategies: Choose between 'timestamp', 'random', or 'original' filenames.

Installation

npm install enhanced-multer-file-uploader

Usage

Basic Usage

By default, this will save files to an uploads folder, limit size to 5MB, and only allow images (jpeg, jpg, png, gif, webp).

import express from 'express';
import { enhancedMulter } from 'enhanced-multer-file-uploader';

const app = express();
const upload = enhancedMulter();

app.post('/upload', upload.single('file'), (req, res) => {
  res.json({ message: 'File uploaded successfully', file: req.file });
});

app.listen(3000, () => console.log('Server started on port 3000'));

Advanced Configuration

Customize destination, size limits, allowed types, and file naming.

import { enhancedMulter } from 'enhanced-multer-file-uploader';

const upload = enhancedMulter({
  destination: 'public/assets',     // Save files to 'public/assets'
  sizeLimitMB: 10,                  // 10MB limit
  allowedTypes: ['pdf', 'docx'],    // Only allow specific types
  filenameParam: 'random',          // Use random filenames
  fileLimit: 5                      // Limit number of files (for array/fields)
});

// Usage with multiple files
app.post('/upload-docs', upload.array('documents', 5), (req, res) => {
  res.json({ files: req.files });
});

API Reference

enhancedMulter(options)

Returns a configured Multer instance.

| Option | Type | Default | Description | |--------|------|---------|-------------| | destination | string | 'uploads' | Directory where files will be saved. Created automatically if missing. | | sizeLimitMB | number | 5 | Maximum file size in Megabytes. | | allowedTypes | string[] | Images | Array of allowed extensions (e.g., ['png']) or mimetypes. If omitted, defaults to standard image types. | | filenameParam | string | 'timestamp' | Naming strategy: 'timestamp' (default), 'original', or 'random'. | | fileLimit | number | undefined | Maximum number of files allowed (useful when using upload.array()). |

Naming Strategies (filenameParam)

• timestamp (Default): fieldname-timestamp-random.ext (e.g., avatar-1678901234-123456789.jpg)
• random: file-timestamp-random.ext (ignores fieldname, useful for privacy)
• original: originalName.ext (⚠️ Warning: can overwrite existing files with same name)

Error Handling

If a file type is rejected, Multer will pass an error to Express. You can catch it in an error handling middleware:

app.use((err, req, res, next) => {
  if (err instanceof multer.MulterError) {
    return res.status(400).json({ error: err.message });
  } else if (err) {
    return res.status(400).json({ error: err.message }); // "File type not allowed..."
  }
  next();
});

License

ISC