fix: handle requests for double slash in dev (#12733)

ascorbic · ematipico · web-flow · commit bbf1d8894e6c · 2025-01-16T12:40:49.000Z
* fix: handle requests for double slash in dev

* Handle base

* Oops

* Snapshots

* Move redirect out of routing

---------

Co-authored-by: Emanuele Stoppa &lt;my.burning@gmail.com&gt;
diff --git a/.changeset/twenty-cherries-switch.md b/.changeset/twenty-cherries-switch.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes a bug that caused the dev server to return an error if requesting "//"
diff --git a/packages/astro/src/core/routing/3xx.ts b/packages/astro/src/core/routing/3xx.ts
@@ -1,5 +1,5 @@
 export type RedirectTemplate = {
-	from: string;
+	from?: string;
 	location: string | URL;
 	status: number;
 };
@@ -14,6 +14,6 @@ export function redirectTemplate({ status, location, from }: RedirectTemplate) {
 <meta name="robots" content="noindex">
 <link rel="canonical" href="${location}">
 <body>
-	<a href="${location}">Redirecting from <code>${from}</code> to <code>${location}</code></a>
+	<a href="${location}">Redirecting ${from ? `from <code>${from}</code> ` : ''}to <code>${location}</code></a>
 </body>`;
 }
diff --git a/packages/astro/src/vite-plugin-astro-server/base.ts b/packages/astro/src/vite-plugin-astro-server/base.ts
@@ -7,7 +7,9 @@ import { appendForwardSlash } from '@astrojs/internal-helpers/path';
 import { bold } from 'kleur/colors';
 import type { Logger } from '../core/logger/core.js';
 import notFoundTemplate, { subpathNotUsedTemplate } from '../template/4xx.js';
-import { writeHtmlResponse } from './response.js';
+import { writeHtmlResponse, writeRedirectResponse } from './response.js';
+
+const manySlashes = /\/{2,}$/;
 
 export function baseMiddleware(
 	settings: AstroSettings,
@@ -21,7 +23,10 @@ export function baseMiddleware(
 
 	return function devBaseMiddleware(req, res, next) {
 		const url = req.url!;
-
+		if (manySlashes.test(url)) {
+			const destination = url.replace(manySlashes, '/');
+			return writeRedirectResponse(res, 301, destination);
+		}
 		let pathname: string;
 		try {
 			pathname = decodeURI(new URL(url, 'http://localhost').pathname);
diff --git a/packages/astro/src/vite-plugin-astro-server/response.ts b/packages/astro/src/vite-plugin-astro-server/response.ts
@@ -7,6 +7,7 @@ import { Readable } from 'node:stream';
 import { getSetCookiesFromResponse } from '../core/cookies/index.js';
 import { getViteErrorPayload } from '../core/errors/dev/index.js';
 import notFoundTemplate from '../template/4xx.js';
+import { redirectTemplate } from '../core/routing/3xx.js';
 
 export async function handle404Response(
 	origin: string,
@@ -53,6 +54,17 @@ export function writeHtmlResponse(res: http.ServerResponse, statusCode: number,
 	res.end();
 }
 
+export function writeRedirectResponse(res: http.ServerResponse, statusCode: number, location: string) {
+	const html = redirectTemplate({ status: statusCode, location });
+	res.writeHead(statusCode, {
+		Location: location,
+		'Content-Type': 'text/html',
+		'Content-Length': Buffer.byteLength(html, 'utf-8'),
+	});
+	res.write(html);
+	res.end();
+}
+
 export async function writeWebResponse(res: http.ServerResponse, webResponse: Response) {
 	const { status, headers, body, statusText } = webResponse;
 
diff --git a/packages/astro/test/dev-routing.test.js b/packages/astro/test/dev-routing.test.js
@@ -48,6 +48,19 @@ describe('Development Routing', () => {
 			assert.equal(response.status, 200);
 		});
 
+		it('redirects when loading double slash', async () => {
+			const response = await fixture.fetch('//', { redirect: 'manual' });
+			assert.equal(response.status, 301);
+			assert.equal(response.headers.get('Location'), '/');
+		});
+
+		it('redirects when loading multiple slashes', async () => {
+			const response = await fixture.fetch('/////', { redirect: 'manual' });
+			assert.equal(response.status, 301);
+			assert.equal(response.headers.get('Location'), '/');
+		});
+
+
 		it('404 when loading invalid dynamic route', async () => {
 			const response = await fixture.fetch('/2');
 			assert.equal(response.status, 404);
