Registry / http-networking / it-multipart

it-multipart

library3.0.14jsnpmunverified

it-multipart is a JavaScript library designed to parse HTTP multipart messages using async iterables. It provides a robust and modern approach to handling streaming data from HTTP requests, particularly useful for file uploads or complex form data. Currently at version 3.0.14, it is part of the broader `it` (InterPlanetary Stream) ecosystem, which emphasizes composable, stream-based utilities. The project demonstrates active maintenance, with frequent updates to various `it-*` packages within its monorepo, suggesting a stable and evolving codebase. Its key differentiator lies in its deep integration with JavaScript's async iterable protocol, making it highly efficient for non-blocking I/O operations and suitable for both Node.js server environments and potentially browser-side stream processing where async iterables are supported. It ships with TypeScript types, ensuring a better developer experience for TypeScript users.

http-networking web-framework serialization data

npm install it-multipart

github ↗package ↗

INSTALL

IMPORT

SIG · IT-MULTIPART

it-multipart

http-networkingjavascriptv3.0.14

Install

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Import

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Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

multipart

✓ import multipart from 'it-multipart'

✗ import { multipart } from 'it-multipart'

The primary `multipart` function is a default export.

multipart (CommonJS)

✓ const multipart = require('it-multipart')

✗ const { multipart } = require('it-multipart')

While primarily an ESM-first library, recent updates in the 'it' monorepo (for related packages like 'it-to-buffer') indicate efforts to support CommonJS `require()` syntax for default exports. Verify compatibility in your specific environment if encountering issues.

Part

✓ import type { Part } from 'it-multipart'

Import the `Part` type for explicit type annotations when working with parsed multipart segments in TypeScript.

This code demonstrates how to create an HTTP server that listens for POST requests with a 'multipart/form-data' content type, parses the incoming multipart message using `it-multipart`, and logs the headers and content of each part.

import http from 'http' import multipart from 'it-multipart' const server = http.createServer(async (req, res) => { if (req.method === 'POST' && req.headers['content-type']) { try { const boundary = req.headers['content-type'].split('boundary=')[1] if (!boundary) { res.writeHead(400, { 'Content-Type': 'text/plain' }) res.end('Missing boundary in Content-Type header') return } for await (const part of multipart(req, boundary)) { console.log(`Received part with headers:`, part.headers) let partContent = '' // nb. part.body must be consumed before the next part is emitted for await (const chunk of part.body) { partContent += chunk.toString() } console.log(`Part name: ${part.name}, Content:`, partContent) } console.log('Finished parsing multipart message.') res.writeHead(200, { 'Content-Type': 'text/plain' }) res.end('Multipart message parsed successfully.') } catch (error) { console.error('Error parsing multipart message:', error) res.writeHead(500, { 'Content-Type': 'text/plain' }) res.end('Error parsing multipart message: ' + error.message) } } else { res.writeHead(404, { 'Content-Type': 'text/plain' }) res.end('Not Found or Unsupported Method') } }) server.listen(5001, () => { console.log('Server listening on port 5001') }) // Example usage with curl: // curl -X POST -H "Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW" -F "field1=value1" -F "file1=@./package.json" http://localhost:5001

Debug

Known issues

gotchaWhen iterating over multipart parts, the `part.body` async iterable for the current part MUST be fully consumed before the next part can be emitted by the `multipart` parser. Failing to consume `part.body` will lead to stalls or incomplete parsing.

fix

Ensure a `for await...of` loop or a similar consumption mechanism processes `part.body` completely for each `part` before the outer loop proceeds to the next `part`.

affects: >=1.0.0

breakingThe `multipart` function now expects the `boundary` string to be passed as a second argument, or inferred from the `req.headers['content-type']`. In previous versions, the boundary might have been automatically extracted or handled differently. Explicitly extracting and passing the boundary ensures correct parsing.

fix

When using `multipart(req)`, ensure `req.headers['content-type']` is available and contains the boundary, or extract it manually and pass it as `multipart(req, boundary)`.

affects: >=3.0.0

gotchaThe `it-multipart` library is built around async iterables. Directly attempting to use it with older Node.js stream APIs (e.g., piping to traditional `Writable` streams) without proper adaptation (e.g., using `it-pipe` or manually iterating) can lead to unexpected behavior or errors.

fix

Embrace the async iterable pattern. Use `for await...of` loops to consume streams or leverage utilities from the `it-pipe` package for more complex stream compositions between async iterables.

affects: >=1.0.0

Errors

Common errors & fixes

TypeError: multipart is not a function or not iterable

Attempting to use `require` with `it-multipart` in a strict ESM context, or an incorrect named import.

fix

Ensure you are using `import multipart from 'it-multipart'` in ESM modules. If using CommonJS, verify the environment's support for importing ESM default exports, or use `const multipart = require('it-multipart')` and test its functionality.

Error: stream has ended or has no more data

Attempting to read from `part.body` after it has been fully consumed or if the upstream stream has closed prematurely, possibly due to not consuming `part.body` for a previous part.

fix

Confirm that `part.body` is fully consumed for each part within its loop, and that the upstream HTTP request stream is correctly handled and not closed before all parts are processed.

Upgrade

Version history

3.0.14latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

8 hits · last 30 days

node

Resources

githubhttps://github.com/achingbrain/it ↗

packagehttps://www.npmjs.com/package/it-multipart ↗