hono-file-upload: streaming file uploads for Hono

[Harshavardhan-Sondakar]

Hi everyone! 👋

I made a small middleware for handling file uploads in Hono: hono-file-upload.

Why

c.req.parseBody() loads the whole file into memory before your handler runs. That's fine for small files, but large uploads use a lot of memory, and you can't stop a bad upload early.

This middleware streams files while they arrive, so a big upload doesn't need a big amount of memory. Size limits are checked during the upload, so an oversized file is stopped right at the limit.

Example

import { Hono } from 'hono'
import { fileUpload } from 'hono-file-upload'

const app = new Hono()

app.post(
  '/avatar',
  fileUpload({
    limits: { fileSize: 2 * 1024 * 1024 }, // 2 MB
    allowedTypes: ['image/*'],
  }),
  (c) => {
    const photo = c.var.upload.file('avatar')
    return c.json({ name: photo?.filename, size: photo?.size })
  },
)

Saving to disk or S3 / Cloudflare R2 is one option away:

import { diskStorage } from 'hono-file-upload/disk'

fileUpload({ storage: diskStorage({ directory: './uploads' }) })

Features

• Streams files to memory, disk, or S3 / R2 / MinIO
• Limits for file size, number of files and fields
• Type checks with wildcards like image/*
• Deletes already saved files if a request fails halfway
• Typed c.var.upload based on the storage you use
• Works on Node.js, Bun, Deno and Cloudflare Workers

Links

• npm: https://www.npmjs.com/package/hono-file-upload
• GitHub: https://github.com/Harshavardhan-Sondakar/hono-file-upload

I'd really like feedback: bugs, missing features, or API ideas. Thanks! 🙏