lws-compress

3.1.0 verified Sat Apr 25 auth: no javascript

Response compression middleware for the lws (local-web-server) framework, enabling gzip compression for HTTP responses. Current stable version is 3.1.0, compatible with Node.js >=12.17. It adds --compress and --compress.threshold CLI options to lws, with a default compression threshold of 1024 bytes. Published under the lwsjs organization, this middleware is a lightweight, focused solution for local development servers, following the standard.js code style.

Common errors

error SyntaxError: Named export 'compress' not found. The requested module 'lws-compress' is a CommonJS module, which may not support all module.exports as named exports. ↓

cause Using named import { compress } from 'lws-compress' with ESM import syntax, but the package no longer provides that named export (since v3).

fix

Use default import: import compress from 'lws-compress'

error Error [ERR_REQUIRE_ESM]: require() of ES Module /path/to/node_modules/lws-compress/index.js from /path/to/project/app.js not supported. ↓

cause Attempting to use require() with an ESM-only package (v3+).

fix

Switch to ESM: use import or type: 'module' in package.json. Or use dynamic import: const compress = (await import('lws-compress')).default

error TypeError: compress is not a function ↓

cause Importing the module incorrectly, e.g., using named import when default import is required.

fix

Ensure you use default import: import compress from 'lws-compress' or const compress = require('lws-compress').default

Warnings

breaking v3 changed from CommonJS to ESM-only. This breaks require() calls in Node.js versions <12.17 or projects not using ESM. ↓

fix Use ESM imports (import compress from 'lws-compress') or upgrade to Node.js >=12.17 and set type: 'module' in package.json. For CJS, use dynamic import: const compress = (await import('lws-compress')).default.

breaking v3 removed the named export 'compress'. Previously both default and named exports were available. ↓

fix Use default import only: import compress from 'lws-compress'.

gotcha Compression threshold is in bytes, not kilobytes. Setting threshold to 1 applies compression to responses >=1 byte, effectively always compressing. ↓

fix Ensure threshold is specified in bytes (e.g., 1024 for 1KB).

gotcha The --compress option must be explicitly passed to enable compression. Without it, no compression occurs even if the middleware is in the stack. ↓

fix Use --compress (or -z) when launching lws, or pass compress: true in lws options.

gotcha Compression only applies to responses with content-type that are compressible (e.g., text/html, application/json). Binary files may be skipped. ↓

fix Check lws documentation for compressible content types or implement custom logic.

Install

npm install lws-compress

yarn add lws-compress

pnpm add lws-compress

Imports

compress

wrong

import { compress } from 'lws-compress'

correct

import compress from 'lws-compress'

Default export since v3.

compress

wrong

const { compress } = require('lws-compress')

correct

const compress = require('lws-compress')

CommonJS: default export, not named.

CompressMiddleware
```
import CompressMiddleware from 'lws-compress'
```
Alias for the default export; no named export exists.

Quickstart

Starts an lws server with response compression middleware, setting a custom compression threshold of 2048 bytes.

import lws from 'lws'
import compress from 'lws-compress'

const server = lws({
  port: 8080,
  stack: [compress],
  compress: {
    threshold: 2048
  }
})
console.log('Server running on http://localhost:8080')