From 44718567d8c495f30a8e9ec620db0ca1298c4fbb Mon Sep 17 00:00:00 2001
From: Richard Harris <richard.a.harris@gmail.com>
Date: Tue, 7 Mar 2023 09:55:34 -0500
Subject: [PATCH] return 308s instead of 301s when normalising paths - fixes
 #9350

---
 .changeset/dirty-pianos-try.md              |  5 +++++
 packages/kit/src/runtime/server/respond.js  |  2 +-
 packages/kit/test/apps/options/test/test.js | 13 ++++++++++++-
 3 files changed, 18 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/dirty-pianos-try.md

diff --git a/.changeset/dirty-pianos-try.md b/.changeset/dirty-pianos-try.md
new file mode 100644
index 000000000000..1a83f174870f
--- /dev/null
+++ b/.changeset/dirty-pianos-try.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+fix: use 308 responses for trailing slash redirects, instead of 301s
diff --git a/packages/kit/src/runtime/server/respond.js b/packages/kit/src/runtime/server/respond.js
index 0707898dff72..13d89588adca 100644
--- a/packages/kit/src/runtime/server/respond.js
+++ b/packages/kit/src/runtime/server/respond.js
@@ -213,7 +213,7 @@ export async function respond(request, options, manifest, state) {
 
 			if (normalized !== url.pathname && !state.prerendering?.fallback) {
 				return new Response(undefined, {
-					status: 301,
+					status: 308,
 					headers: {
 						'x-sveltekit-normalize': '1',
 						location:
diff --git a/packages/kit/test/apps/options/test/test.js b/packages/kit/test/apps/options/test/test.js
index d50125ae8c7b..4228c128c0d9 100644
--- a/packages/kit/test/apps/options/test/test.js
+++ b/packages/kit/test/apps/options/test/test.js
@@ -1,3 +1,4 @@
+import * as http from 'node:http';
 import { expect } from '@playwright/test';
 import { test } from '../../../utils.js';
 
@@ -172,7 +173,17 @@ test.describe('env', () => {
 });
 
 test.describe('trailingSlash', () => {
-	test('adds trailing slash', async ({ baseURL, page, clicknav }) => {
+	test.only('adds trailing slash', async ({ baseURL, page, clicknav }) => {
+		// we can't use Playwright's `request` here, because it resolves redirects
+		const status = await new Promise((fulfil, reject) => {
+			const request = http.get(`${baseURL}/path-base/slash`);
+			request.on('error', reject);
+			request.on('response', (response) => {
+				fulfil(response.statusCode);
+			});
+		});
+		expect(status).toBe(308);
+
 		await page.goto('/path-base/slash');
 
 		expect(page.url()).toBe(`${baseURL}/path-base/slash/`);