remix-run/remix multipart-parser@1.1.0

multipart-parser v1.1.0

on GitHub

Minor Changes

• Add a @remix-run/multipart-parser/future entrypoint with a streaming multipart parser. Future APIs are not stable and may change in any release, but they are a good indication of where this package will land in its next major release. (#12030)

  parseMultipartRequest() and parseMultipartStream() from /future yield each MultipartPart as soon as its headers arrive, instead of after its content is buffered. Part content streams from the request body as you read it, so large files are never held in memory. Read each part once with part.body, await part.bytes(), await part.text(), or for await...of; content you skip is discarded when you continue to the next part. Breaking out of the loop early cancels the request body.

  import { parseMultipartRequest } from '@remix-run/multipart-parser/future'
  
  for await (let part of parseMultipartRequest(request)) {
    if (part.isFile) {
      await saveFile(part.filename, part.body)
    } else {
      console.log(part.name, await part.text())
    }
  }

  Because parts are yielded before their content is buffered, a large file is available to your code almost immediately, and memory stays flat no matter how big it is. Measured on Node.js 24.18 with an Apple M5 Pro, as the median of 7 runs that each use a fresh process, reading every part's content with parseMultipartRequest():

  Request	Total time (stable → future)	Time until the first file part is yielded	Peak memory growth
  1 × 100 MiB file	37.0 ms → 34.8 ms	36.9 ms → 0.2 ms	100 MiB → 44 MiB
  5 × 20 MiB files	37.8 ms → 35.1 ms	8.4 ms → 0.2 ms	59 MiB → 23 MiB
  10 fields and an 8 KiB file	0.43 ms → 0.47 ms	0.41 ms → 0.39 ms	No measurable change

  Compared to the stable entrypoint, /future drops the synchronous parseMultipart(), the MultipartParser class, and the /node entrypoint, and MultipartPart no longer has the arrayBuffer, bytes, content, isText, size, and text getters. The error classes are shared with the stable entrypoint, so instanceof checks work with either.

  If your app handles file uploads, please give @remix-run/multipart-parser/future a try and tell us how it goes in GitHub Discussions. We'd especially like to hear about anything that breaks, behaves unexpectedly, or feels awkward, since that feedback will shape the next major release.

Patch Changes

• Bumped @remix-run/* dependencies:
  • headers@1.0.1