Registry / web-framework / rspack-dev-middleware

rspack-dev-middleware

library0.4.0jsnpmunverified

A Koa 2 middleware for Rspack development and hot reloading. Current stable version 0.4.0, released under Apache-2.0 license with weekly releases. Supports ESM-only with TypeScript types. Key differentiators: designed specifically for Koa 2, integrates with memfs for in-memory file systems, and provides built-in hot reloading without Webpack dependencies. Requires Node.js >=18 and peer deps @rspack/core >=1.0.7 and koa >=2.0.0. Tree-shakable with no side effects.

web-framework devops

npm install rspack-dev-middleware

github ↗package ↗

INSTALL

IMPORT

SIG · RSPACK-DEV-MIDDLEW

rspack-dev-middleware

web-frameworkjavascriptv0.4.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

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

server

✓ import { server } from 'rspack-dev-middleware'

✗ const server = require('rspack-dev-middleware').server

ESM-only package; named export `server` is the default middleware function.

default

✓ import dev from 'rspack-dev-middleware'

✗ const dev = require('rspack-dev-middleware')

Package has a default export that is identical to the named `server` export.

type imports

✓ import type { Middleware } from 'rspack-dev-middleware'

✗ import { Middleware } from 'rspack-dev-middleware'

Middleware type is available for TypeScript users as a type export.

Sets up a Koa server with Rspack dev middleware, using memfs for in-memory file output and hot reloading.

import Koa from 'koa'; import rspack from '@rspack/core'; import { Volume, createFsFromVolume } from 'memfs'; import { server as dev } from 'rspack-dev-middleware'; const compiler = rspack({ mode: 'development', entry: './src/index.tsx', output: { path: '/dist' }, }); const app = new Koa(); const fs = createFsFromVolume(new Volume()); app.use(await dev(compiler, { fs, headers: { 'Cache-Control': 'no-cache' } })); app.listen(3000);

Debug

Known issues

breakingPackage is ESM-only and cannot be required via CommonJS require().

fix

Use import syntax or dynamic import().

affects: >=0.0.0

deprecatedOption `writeToDisk` is removed; use `fs` to customize output instead.

fix

Pass a custom `fs` object (e.g., memfs) to middleware options.

affects: >=0.3.0

gotchaPassing an array of compilers is not supported; use a single compiler instance.

fix

Wrap multiple compilers in a multi-compiler if needed, but note that rspack-dev-middleware only accepts a single compiler.

affects: >=0.0.0

gotchaMiddleware must be awaited; `app.use(dev(...))` without await may cause errors.

fix

Use `app.use(await dev(compiler, options))`.

affects: >=0.0.0

Errors

Common errors & fixes

ERR_REQUIRE_ESM: require() of ES Module not supported

Using CommonJS require() on an ESM-only package.

fix

Change to dynamic import or set type: 'module' in package.json.

TypeError: compiler is not an object

Passing an array of compilers instead of a single compiler instance.

fix

Pass a single compiler object, e.g., `rspack({...})`.

Error: Cannot find module 'koa'

Missing peer dependency koa.

fix

Install koa: npm install koa.

Upgrade

Version history

0.4.0latest on npm

Audit

Dependencies

@rspack/corerequiredPeer dependency for Rspack compiler instance

koarequiredPeer dependency for Koa 2 middleware framework

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/nuintun/rspack-dev-middleware ↗

packagehttps://www.npmjs.com/package/rspack-dev-middleware ↗