File Uploads

Uploading files with Express usually requires wrestling with multer middleware on a route-by-route basis. bro.js makes it a one-liner.

Zero-Boilerplate Uploads

Simply add upload: true to your route configuration. The framework will automatically parse multipart/form-data requests and inject the file objects right into your context.

import { defineRoute } from 'bro-framework';
 
export default defineRoute({
  upload: true, // That's literally it for any-file uploads.
  handler: async ({ files, body }) => {
    // files is an array of uploaded file objects (buffered in memory)
    const uploadedImages = files.filter(f => f.mimetype.startsWith('image/'));
    
    return {
      message: `Successfully received ${uploadedImages.length} images!`,
      meta: body // You still get access to other form fields
    };
  }
});

Granular Upload Configurations

For production systems, you should be extremely specific about what files you accept. bro.js supports granular object configurations:

Single File Uploads

When expecting exactly one file under a specific field name, use upload: { single: 'fieldName' }. The file is injected as ctx.file (singular).

export default defineRoute({
  upload: {
    single: 'avatar',
    limits: { fileSize: 5 * 1024 * 1024 } // Override default 10MB limit to 5MB
  },
  handler: async ({ file }) => {
    return { filename: file.originalname, size: file.size };
  }
});

Multiple Fields & Custom Limits

You can restrict uploads to specific fields and counts using upload: { fields: [] }. The files are injected as ctx.files, which acts as a dictionary keyed by field name.

export default defineRoute({
  upload: {
    fields: [
      { name: 'avatar', maxCount: 1 },
      { name: 'gallery', maxCount: 4 }
    ],
    // You can also provide custom multer storage or fileFilter
    // storage: customStorageEngine,
    // fileFilter: customFileFilter
  },
  handler: async ({ files }) => {
    return {
      avatar: files['avatar']?.[0]?.originalname,
      galleryCount: files['gallery']?.length || 0
    };
  }
});

Built-In Safety Limits

[!TIP] Production Best Practices By default, multer buffers files entirely in RAM. For heavy traffic or large file uploads, it is strongly advised to configure disk storage via the storage configuration option. Additionally, remember to set proxy-level limits (like client_max_body_size in Nginx) to drop oversized payloads before they even reach Node.js.

By default, bro.js protects your server with strict resource limits. These apply globally unless overridden in bro.config.js or directly at the route level:

• fileSize: 10 MB (10 * 1024 * 1024 bytes)
• files: 5 (Max number of files per request)
• fields: 20 (Max number of non-file fields)
• parts: 25 (Max multipart fields + files)
• fieldSize: 1 MB (Max size for non-file text fields)