next.js

0f332055 - fix: Standalone node http server starts accepting requests before next handler is ready (#49548)

fix: Standalone node http server starts accepting requests before next handler is ready (#49548) ### Fixing a bug Fixes #49536 Fixes #49338 ### What? Starting on next.js 13.4.0, the `server.js` file created by the standalone output is incorrect because it does not wait until the Next handler is ready before node http server starts accepting requests. Initial requests will produce the following error: ``` TypeError: handler is not a function at Server.<anonymous> (/tmp/app/server.js:29:11) at Server.emit (node:events:513:28) at parserOnIncoming (node:_http_server:998:12) at HTTPParser.parserOnHeadersComplete (node:_http_common:128:17) ``` ### Why? The creation of the next server takes roughly 800ms on a basic hello world app which causes the initial requests to fail because the `handler` variable is not initialized. ### Solution This changes the order of code so that Next Server is initialized before the Node HTTP server and awaits until the promise is completed to kick off the HTTP server. ### Alternative code ```js let handler; const server = http.createServer(async (req, res) => { try { await waitUntilHandlerIsReady(); // <---- wait here await handler(req, res); } catch (err) { console.error("Failed to call handler", err); res.statusCode = 500; res.end("Internal Server Error"); } }); async function waitUntilHandlerIsReady() { if (!handler) { await new Promise((resolve) => setTimeout(resolve, 200)); await waitUntilHandlerIsReady(); } } ``` --------- Co-authored-by: Tim Neutkens <tim@timneutkens.nl> Co-authored-by: JJ Kasper <jj@jjsweb.site>