polyfill-bundler

<!-- Include this in your HTML to use the self-hosted polyfill service --> <script src="https://polyfill.your.domain/polyfill.js?features=AbortController,Array.from,Promise.prototype.finally"></script> // Example of how to start a very basic (not production-ready) Node.js server // that could theoretically serve polyfills, assuming polyfill-bundler provides // an API to generate them. (Note: The exact API for 'polyfill-bundler' as a library // to generate bundles programmatically is not directly exposed in the README snippet; // this is a conceptual server illustrating the client-side usage.) const http = require('http'); const url = require('url'); // In a real application, 'polyfill-bundler' would be used here to generate the bundle. // For this example, we'll simulate a response. function generatePolyfillBundle(features) { console.log(`Generating polyfill for features: ${features.join(', ')}`); // In a real scenario, this would use the polyfill-bundler logic // to detect user-agent and generate a minified, targeted polyfill string. // For demonstration, a simple placeholder. let bundle = ''; if (features.includes('AbortController')) bundle += '/* AbortController polyfill */\nself.AbortController = self.AbortController || function AbortController() { this.signal = { aborted: false }; };\n'; if (features.includes('Array.from')) bundle += '/* Array.from polyfill */\nif (!Array.from) { Array.from = (iterable) => [...iterable]; }\n'; if (features.includes('Promise.prototype.finally')) bundle += '/* Promise.finally polyfill */\nif (!Promise.prototype.finally) { Promise.prototype.finally = function(cb) { const P = this.constructor || Promise; return this.then(val => P.resolve(cb()).then(() => val), err => P.resolve(cb()).then(() => { throw err; })); }; }\n'; return bundle; } const server = http.createServer((req, res) => { const parsedUrl = url.parse(req.url, true); if (parsedUrl.pathname === '/polyfill.js') { const featuresParam = parsedUrl.query.features; const features = featuresParam ? featuresParam.split(',') : []; const polyfillCode = generatePolyfillBundle(features); res.writeHead(200, { 'Content-Type': 'application/javascript' }); res.end(polyfillCode); } else { res.writeHead(404, { 'Content-Type': 'text/plain' }); res.end('Not Found'); } }); const PORT = process.env.PORT ?? 3000; server.listen(PORT, () => { console.log(`Polyfill service running at http://localhost:${PORT}`); console.log('Access via: http://localhost:3000/polyfill.js?features=AbortController,Array.from'); });