From f5cc2b0ace364069085406cf520fffaef4176726 Mon Sep 17 00:00:00 2001
From: dataCenter430 <161712630+dataCenter430@users.noreply.github.com>
Date: Mon, 16 Mar 2026 21:47:28 +0100
Subject: [PATCH] fix(dev): register base middleware when using non-runnable
 SSR (#15947)

---
 .../src/vite-plugin-astro-server/plugin.ts    | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/packages/astro/src/vite-plugin-astro-server/plugin.ts b/packages/astro/src/vite-plugin-astro-server/plugin.ts
index 89ff91b5a53e..706e8924500e 100644
--- a/packages/astro/src/vite-plugin-astro-server/plugin.ts
+++ b/packages/astro/src/vite-plugin-astro-server/plugin.ts
@@ -61,11 +61,6 @@ export default function createVitePluginAstroServer({
 				? (prerenderEnvironment as RunnableDevEnvironment)
 				: undefined;
 
-			// TODO: let this handle non-runnable environments that don't intercept requests
-			if (!runnableSsrEnvironment && !runnablePrerenderEnvironment) {
-				return;
-			}
-
 			async function createHandler(environment: RunnableDevEnvironment) {
 				const loader = createViteLoader(viteServer, environment);
 				const { default: createAstroServerApp } =
@@ -117,20 +112,18 @@ export default function createVitePluginAstroServer({
 				}
 			}
 
-			process.on('unhandledRejection', handleUnhandledRejection);
-			viteServer.httpServer?.on('close', () => {
-				process.off('unhandledRejection', handleUnhandledRejection);
-			});
+			if (ssrHandler || prerenderHandler) {
+				process.on('unhandledRejection', handleUnhandledRejection);
+				viteServer.httpServer?.on('close', () => {
+					process.off('unhandledRejection', handleUnhandledRejection);
+				});
+			}
 
 			return () => {
 				const shouldHandlePrerenderInCore = Boolean(
 					(viteServer as any)[devPrerenderMiddlewareSymbol],
 				);
 
-				if (!ssrHandler && !(prerenderHandler && shouldHandlePrerenderInCore)) {
-					return;
-				}
-
 				// Push this middleware to the front of the stack so that it can intercept responses.
 				// fix(#6067): always inject this to ensure zombie base handling is killed after restarts
 				viteServer.middlewares.stack.unshift({