fix(routing): call middleware when rendering 404.astro (#12034)

.changeset/clever-vans-flash.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes an issue where the middleware wasn't called when a project uses `404.astro`.

packages/astro/src/vite-plugin-astro-server/route.ts

@@ -1,6 +1,7 @@
 import type http from 'node:http';
 import type { ComponentInstance, ManifestData, RouteData } from '../@types/astro.js';
 import {
+	DEFAULT_404_COMPONENT,
 	REROUTE_DIRECTIVE_HEADER,
 	REWRITE_DIRECTIVE_HEADER_KEY,
 	clientLocalsSymbol,
@@ -192,13 +193,16 @@ export async function handleRoute({
 
 	mod = preloadedComponent;
 
-	const isPrerendered404 = matchedRoute.route.route === '/404' && matchedRoute.route.prerender;
+	const isDefaultPrerendered404 =
+		matchedRoute.route.route === '/404' &&
+		matchedRoute.route.prerender &&
+		matchedRoute.route.component === DEFAULT_404_COMPONENT;
 
 	renderContext = RenderContext.create({
 		locals,
 		pipeline,
 		pathname,
-		middleware: isPrerendered404 ? undefined : middleware,
+		middleware: isDefaultPrerendered404 ? undefined : middleware,
 		request,
 		routeData: route,
 	});

packages/astro/test/i18n-routing-manual.test.js

@@ -53,9 +53,9 @@ describe('Dev server manual routing', () => {
 		assert.equal(text.includes('Hola.'), true);
 	});
 
-	it('should not redirect prerendered 404 routes in dev', async () => {
+	it('should call the middleware for 404.astro pages', async () => {
 		const response = await fixture.fetch('/redirect-me');
-		assert.equal(response.status, 404);
+		assert.equal(response.status, 200);
 	});
 });