fix(middleware): do not import user middleware if not preset (#9057)

13 files changed, 123 insertions, 10 deletions

diff --git a/.changeset/chilled-swans-appear.md b/.changeset/chilled-swans-appear.md
new file mode 100644
index 000000000..af7b37da6
--- /dev/null
+++ b/.changeset/chilled-swans-appear.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Correctly infer the presence of an user middleware
diff --git a/packages/astro/src/core/middleware/vite-plugin.ts b/packages/astro/src/core/middleware/vite-plugin.ts
index 790c76129..044713491 100644
--- a/packages/astro/src/core/middleware/vite-plugin.ts
+++ b/packages/astro/src/core/middleware/vite-plugin.ts
@@ -15,6 +15,7 @@ export function vitePluginMiddleware({ settings }: { settings: AstroSettings }):
 	let resolvedMiddlewareId: string | undefined = undefined;
 	const hasIntegrationMiddleware =
 		settings.middlewares.pre.length > 0 || settings.middlewares.post.length > 0;
+	let userMiddlewareIsPresent = false;
 
 	return {
 		name: '@astro/plugin-middleware',
@@ -29,6 +30,7 @@ export function vitePluginMiddleware({ settings }: { settings: AstroSettings }):
 				const middlewareId = await this.resolve(
 					`${decodeURI(settings.config.srcDir.pathname)}${MIDDLEWARE_PATH_SEGMENT_NAME}`
 				);
+				userMiddlewareIsPresent = !!middlewareId;
 				if (middlewareId) {
 					resolvedMiddlewareId = middlewareId.id;
 					return MIDDLEWARE_MODULE_ID;
@@ -61,13 +63,17 @@ export function vitePluginMiddleware({ settings }: { settings: AstroSettings }):
 				const postMiddleware = createMiddlewareImports(settings.middlewares.post, 'post');
 
 				const source = `
-import { onRequest as userOnRequest } from '${resolvedMiddlewareId}';
+				${
+					userMiddlewareIsPresent
+						? `import { onRequest as userOnRequest } from '${resolvedMiddlewareId}';`
+						: ''
+				}
 import { sequence } from 'astro:middleware';
 ${preMiddleware.importsCode}${postMiddleware.importsCode}
 
 export const onRequest = sequence(
 	${preMiddleware.sequenceCode}${preMiddleware.sequenceCode ? ',' : ''}
-	userOnRequest${postMiddleware.sequenceCode ? ',' : ''}
+	${userMiddlewareIsPresent ? `userOnRequest${postMiddleware.sequenceCode ? ',' : ''}` : ''}
 	${postMiddleware.sequenceCode}
 );
 `.trim();
diff --git a/packages/astro/test/fixtures/middleware space/integration-middleware-post.js b/packages/astro/test/fixtures/middleware space/integration-middleware-post.js
index 4cc63c6b7..a4e0c90ad 100644
--- a/packages/astro/test/fixtures/middleware space/integration-middleware-post.js
+++ b/packages/astro/test/fixtures/middleware space/integration-middleware-post.js
@@ -1,11 +1,11 @@
-import { sequence, defineMiddleware } from 'astro:middleware';
+import { defineMiddleware } from 'astro:middleware';
 
 export const onRequest = defineMiddleware((context, next) => {
-	if(context.url.pathname === '/integration-post') {
+	if (context.url.pathname === '/integration-post') {
 		return new Response(JSON.stringify({ post: 'works' }), {
 			headers: {
-				'content-type': 'application/json'
-			}
+				'content-type': 'application/json',
+			},
 		});
 	}
 
diff --git a/packages/astro/test/fixtures/middleware space/integration-middleware-pre.js b/packages/astro/test/fixtures/middleware space/integration-middleware-pre.js
index 3bf484b2b..1ebf28066 100644
--- a/packages/astro/test/fixtures/middleware space/integration-middleware-pre.js
+++ b/packages/astro/test/fixtures/middleware space/integration-middleware-pre.js
@@ -1,11 +1,11 @@
-import { sequence, defineMiddleware } from 'astro:middleware';
+import { defineMiddleware } from 'astro:middleware';
 
 export const onRequest = defineMiddleware((context, next) => {
-	if(context.url.pathname === '/integration-pre') {
+	if (context.url.pathname === '/integration-pre') {
 		return new Response(JSON.stringify({ pre: 'works' }), {
 			headers: {
-				'content-type': 'application/json'
-			}
+				'content-type': 'application/json',
+			},
 		});
 	}
 
diff --git a/packages/astro/test/fixtures/middleware-no-user-middleware/astro.config.mjs b/packages/astro/test/fixtures/middleware-no-user-middleware/astro.config.mjs
new file mode 100644
index 000000000..ffae133be
--- /dev/null
+++ b/packages/astro/test/fixtures/middleware-no-user-middleware/astro.config.mjs
@@ -0,0 +1,23 @@
+import {defineConfig} from "astro/config";
+import {fileURLToPath} from "node:url";
+
+export default defineConfig({
+	integrations: [
+		{
+			name: 'my-middleware',
+			hooks: {
+				'astro:config:setup':({ addMiddleware }) => {
+					addMiddleware({
+						entrypoint: fileURLToPath(new URL('./integration-middleware-pre.js', import.meta.url)),
+						order: 'pre'
+					});
+
+					addMiddleware({
+						entrypoint: fileURLToPath(new URL('./integration-middleware-post.js', import.meta.url)),
+						order: 'post'
+					});
+				}
+			}
+		}
+	]
+});
diff --git a/packages/astro/test/fixtures/middleware-no-user-middleware/integration-middleware-post.js b/packages/astro/test/fixtures/middleware-no-user-middleware/integration-middleware-post.js
new file mode 100644
index 000000000..18c8969c3
--- /dev/null
+++ b/packages/astro/test/fixtures/middleware-no-user-middleware/integration-middleware-post.js
@@ -0,0 +1,13 @@
+import { defineMiddleware } from 'astro:middleware';
+
+export const onRequest = defineMiddleware((context, next) => {
+	if (context.url.pathname === '/post') {
+		return new Response(JSON.stringify({ post: 'works' }), {
+			headers: {
+				'content-type': 'application/json',
+			},
+		});
+	}
+
+	return next();
+});
diff --git a/packages/astro/test/fixtures/middleware-no-user-middleware/integration-middleware-pre.js b/packages/astro/test/fixtures/middleware-no-user-middleware/integration-middleware-pre.js
new file mode 100644
index 000000000..07bb16b46
--- /dev/null
+++ b/packages/astro/test/fixtures/middleware-no-user-middleware/integration-middleware-pre.js
@@ -0,0 +1,13 @@
+import { defineMiddleware } from 'astro:middleware';
+
+export const onRequest = defineMiddleware((context, next) => {
+	if (context.url.pathname === '/pre') {
+		return new Response(JSON.stringify({ pre: 'works' }), {
+			headers: {
+				'content-type': 'application/json',
+			},
+		});
+	}
+
+	return next();
+});
diff --git a/packages/astro/test/fixtures/middleware-no-user-middleware/package.json b/packages/astro/test/fixtures/middleware-no-user-middleware/package.json
new file mode 100644
index 000000000..9a2a378ed
--- /dev/null
+++ b/packages/astro/test/fixtures/middleware-no-user-middleware/package.json
@@ -0,0 +1,8 @@
+{
+  "name": "@test/middleware-no-user-middlewaqre",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "astro": "workspace:*"
+  }
+}
diff --git a/packages/astro/test/fixtures/middleware-no-user-middleware/src/pages/index.astro b/packages/astro/test/fixtures/middleware-no-user-middleware/src/pages/index.astro
new file mode 100644
index 000000000..822b15cd3
--- /dev/null
+++ b/packages/astro/test/fixtures/middleware-no-user-middleware/src/pages/index.astro
@@ -0,0 +1,14 @@
+---
+const data = Astro.locals;
+---
+
+<html>
+<head>
+    <title>Testing</title>
+</head>
+<body>
+
+<span>Index</span>
+<p>{data?.name}</p>
+</body>
+</html>
diff --git a/packages/astro/test/fixtures/middleware-no-user-middleware/src/pages/post.astro b/packages/astro/test/fixtures/middleware-no-user-middleware/src/pages/post.astro
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/packages/astro/test/fixtures/middleware-no-user-middleware/src/pages/post.astro
diff --git a/packages/astro/test/fixtures/middleware-no-user-middleware/src/pages/pre.astro b/packages/astro/test/fixtures/middleware-no-user-middleware/src/pages/pre.astro
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/packages/astro/test/fixtures/middleware-no-user-middleware/src/pages/pre.astro
diff --git a/packages/astro/test/middleware.test.js b/packages/astro/test/middleware.test.js
index a9487950e..8332dfe41 100644
--- a/packages/astro/test/middleware.test.js
+++ b/packages/astro/test/middleware.test.js
@@ -99,6 +99,31 @@ describe('Middleware in DEV mode', () => {
 			expect(json.post).to.equal('works');
 		});
 	});
+
+	describe('Integration hooks with no user middleware', () => {
+		before(async () => {
+			fixture = await loadFixture({
+				root: './fixtures/middleware-no-user-middleware/',
+			});
+			devServer = await fixture.startDevServer();
+		});
+
+		after(async () => {
+			await devServer.stop();
+		});
+
+		it('Integration middleware marked as "pre" runs', async () => {
+			let res = await fixture.fetch('/pre');
+			let json = await res.json();
+			expect(json.pre).to.equal('works');
+		});
+
+		it('Integration middleware marked as "post" runs', async () => {
+			let res = await fixture.fetch('/post');
+			let json = await res.json();
+			expect(json.post).to.equal('works');
+		});
+	});
 });
 
 describe('Middleware in PROD mode, SSG', () => {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 322d1a4f7..d7ee1b767 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2957,6 +2957,12 @@ importers:
         specifier: workspace:*
         version: link:../../..
 
+  packages/astro/test/fixtures/middleware-no-user-middleware:
+    dependencies:
+      astro:
+        specifier: workspace:*
+        version: link:../../..
+
   packages/astro/test/fixtures/middleware-ssg:
     dependencies:
       astro: