Visit /js/app.js to see minified output.
Check the console for debug messages if `debug: true`.
');\n});\n\napp.listen(port, () => {\n console.log(`Server listening at http://localhost:${port}`);\n console.log(`Source JS: ${javascriptSourceDir}`);\n console.log(`Minified JS (expected): ${path.join(publicJsDestDir, 'app.js')}`);\n console.log('You might need to clear browser cache for changes to appear if `force: false`.');\n});","lang":"javascript","description":"This quickstart sets up a basic Express application that uses `express-uglify-middleware` to dynamically minify a source JavaScript file into a public directory, serving it via a '/js' prefix. It demonstrates the configuration options and a simple Express server setup."},"warnings":[{"fix":"Do not use this package in modern Node.js environments. For current projects, utilize build tools like Webpack or Vite with Terser for JavaScript minification.","message":"This package is designed for Node.js environments `>= 0.8.0` and is incompatible with modern Node.js versions (e.g., Node.js 12+). Running it on recent Node.js versions will likely result in runtime errors due to API changes and deprecated modules.","severity":"breaking","affected_versions":">=1.0.0"},{"fix":"Avoid using this middleware for modern JavaScript. Modern projects should use build tools with up-to-date minifiers like Terser that support the latest ECMAScript features.","message":"The package likely uses an extremely old version of UglifyJS, which does not support modern JavaScript syntax (ES2015+). Attempting to minify ES6+ code will result in `SyntaxError`s or incorrect minification.","severity":"breaking","affected_versions":">=1.0.0"},{"fix":"This package is not compatible with modern Express applications. Consider a different approach for asset management that integrates with current Express practices.","message":"This middleware was built for older Express versions (likely 3.x or 4.x). While basic `app.use` might still function, deep incompatibilities with Express 5.x or newer middleware patterns are highly probable, leading to unexpected behavior or errors.","severity":"breaking","affected_versions":">=1.0.0"},{"fix":"Adopt a build-time asset compilation workflow (e.g., Webpack, Rollup, Vite) to minify JavaScript before deployment. Serve pre-minified assets as static files, potentially via a CDN, for optimal performance and scalability.","message":"The pattern of dynamic, on-the-fly minification in a production environment is generally considered an anti-pattern. It adds latency to requests, consumes server resources for each un-cached request, and complicates caching strategies. Modern best practices involve pre-building and minifying assets at deploy time.","severity":"deprecated","affected_versions":">=1.0.0"},{"fix":"Ensure `force: false` (or omit it for the default `false`) in production environments to enable caching of minified files and avoid redundant processing.","message":"The `force: true` option (as shown in the example) will re-minify files on every request, which is highly inefficient and detrimental to performance in production. While useful for development, it must be set to `false` or removed for production deployments.","severity":"gotcha","affected_versions":">=1.0.0"}],"env_vars":null,"last_verified":"2026-04-23T00:00:00.000Z","next_check":"2026-07-22T00:00:00.000Z","problems":[{"fix":"Ensure `uglify-js` is installed locally: `npm install uglify-js`.","cause":"The `uglify-js` package, a peer dependency, was not installed or is inaccessible.","error":"Error: Cannot find module 'uglify-js'"},{"fix":"This package cannot minify modern JavaScript. You must either transpile your code to ES5 before passing it to this middleware or, preferably, migrate to a modern build pipeline with an up-to-date minifier like Terser.","cause":"The version of UglifyJS used by this middleware does not support ES6 (ECMAScript 2015) or newer syntax.","error":"SyntaxError: Unexpected token: keyword 'const'"},{"fix":"Verify that `express` is correctly installed and imported, and that you are working with an Express `Application` instance. However, this package is fundamentally incompatible with modern Express versions.","cause":"This error typically indicates an issue with how Express is being initialized or an incompatibility with an extremely old (pre-2.x) or corrupted Express installation.","error":"TypeError: app.use is not a function"},{"fix":"This middleware is for server-side processing with Express. It generates static assets that are then served to the browser. Do not attempt to bundle or run `express-uglify-middleware` client-side.","cause":"This package is a Node.js server-side middleware and cannot be run directly in a browser environment.","error":"ReferenceError: require is not defined (in browser)"}],"ecosystem":"npm","meta_description":null,"install_score":null,"install_tag":null,"quickstart_score":null,"quickstart_tag":null}