1 files changed, 52 insertions, 0 deletions
diff --git a/packages/integrations/node/src/serve-app.ts b/packages/integrations/node/src/serve-app.ts
new file mode 100644
index 000000000..2934a01ab
--- /dev/null
+++ b/packages/integrations/node/src/serve-app.ts
@@ -0,0 +1,52 @@
+import { AsyncLocalStorage } from 'node:async_hooks';
+import { NodeApp } from 'astro/app/node';
+import type { RequestHandler } from './types.js';
+
+/**
+ * Creates a Node.js http listener for on-demand rendered pages, compatible with http.createServer and Connect middleware.
+ * If the next callback is provided, it will be called if the request does not have a matching route.
+ * Intended to be used in both standalone and middleware mode.
+ */
+export function createAppHandler(app: NodeApp): RequestHandler {
+	/**
+	 * Keep track of the current request path using AsyncLocalStorage.
+	 * Used to log unhandled rejections with a helpful message.
+	 */
+	const als = new AsyncLocalStorage<string>();
+	const logger = app.getAdapterLogger();
+	process.on('unhandledRejection', (reason) => {
+		const requestUrl = als.getStore();
+		logger.error(`Unhandled rejection while rendering ${requestUrl}`);
+		console.error(reason);
+	});
+
+	return async (req, res, next, locals) => {
+		let request: Request;
+		try {
+			request = NodeApp.createRequest(req);
+		} catch (err) {
+			logger.error(`Could not render ${req.url}`);
+			console.error(err);
+			res.statusCode = 500;
+			res.end('Internal Server Error');
+			return;
+		}
+
+		const routeData = app.match(request);
+		if (routeData) {
+			const response = await als.run(request.url, () =>
+				app.render(request, {
+					addCookieHeader: true,
+					locals,
+					routeData,
+				})
+			);
+			await NodeApp.writeResponse(response, res);
+		} else if (next) {
+			return next();
+		} else {
+			const response = await app.render(req);
+			await NodeApp.writeResponse(response, res);
+		}
+	};
+}