Issue with NextResponse.rewrite(). It redirects instead of rewrites

Support
, ,
1

Hi,

I have a problem with the rewrite() method of the NextResponse function inside middleware.
It works perfectly, but on the index page, it actually redirects to /en for some reason. The website is - https://preview.edgeless.systems

Here is the middleware.ts content:

import { i18n } from "@/i18n.config";
import { match as matchLocale } from "@formatjs/intl-localematcher";
import Negotiator from "negotiator";
import type { NextRequest } from "next/server";
import { NextResponse } from "next/server";

function getLocale(request: NextRequest): string | undefined {
  const negotiatorHeaders: Record<string, string> = {};
  request.headers.forEach((value, key) => (negotiatorHeaders[key] = value));

  const locales = i18n.locales;
  const languages = new Negotiator({ headers: negotiatorHeaders }).languages();

  const locale = matchLocale(languages, locales, i18n.defaultLocale);

  return locale;
}

export function middleware(request: NextRequest) {
  const pathname = request.nextUrl.pathname;
  const pathnameIsMissingLocale = i18n.locales.every(
    (locale) =>
      !pathname.startsWith(`/${locale}/`) && pathname !== `/${locale}`,
  );

  console.log("===================================");

  console.log("Pathname:", pathname);

  // Redirect if there is no locale
  if (pathnameIsMissingLocale) {
    const locale = getLocale(request);

    if (locale === i18n.defaultLocale) {
      const url = new URL(
        `/${locale}${pathname.startsWith("/") ? "" : "/"}${pathname}`,
        request.url,
      );

      console.log("URL: " + url.toString());

      return NextResponse.rewrite(url);
    }
  }
}

export const config = {
  matcher: [`/((?!_next|svg|meta|api|slice-simulator|sitemap.xml|icon.svg).*)`],
};

Edge Functions Logs:

Apr 21, 02:28:50 PM: 01HW0A2V info   [___netlify-edge-handler-src-middleware] ===================================
Apr 21, 02:28:50 PM: 01HW0A2V info   [___netlify-edge-handler-src-middleware] Pathname: /
Apr 21, 02:28:50 PM: 01HW0A2V info   [___netlify-edge-handler-src-middleware] Locale: en
Apr 21, 02:28:50 PM: 01HW0A2V info   [___netlify-edge-handler-src-middleware] Languages: [ "uk", "en" ]
Apr 21, 02:28:50 PM: 01HW0A2V info   [___netlify-edge-handler-src-middleware] Locales: [ "en", "de" ]
Apr 21, 02:28:50 PM: 01HW0A2V info   [___netlify-edge-handler-src-middleware] Default Locale: en
Apr 21, 02:28:50 PM: 01HW0A2V info   [___netlify-edge-handler-src-middleware] Is defaultLocale
Apr 21, 02:28:50 PM: 01HW0A2V info   [___netlify-edge-handler-src-middleware] URL: https://preview.edgeless.systems/en/
Apr 21, 02:28:50 PM: 01HW0A2V info   [___netlify-edge-handler-src-middleware] ===================================
Apr 21, 02:28:50 PM: 01HW0A2V info   [___netlify-edge-handler-src-middleware] Pathname: /en   <- REDIRECTED
Apr 21, 02:28:51 PM: 01HW0A2W info   [___netlify-edge-handler-src-middleware] ===================================

Please note, it happens with the index page only. There are no redirects anywhere in the project.
No problem locally and on Vercel. It happens only on Netlify.

Stack used:

Next.js 14.1
Next.js Runtime - v5.1.2

Content of autogenerated netlify.toml: 
[[redirects]]
from = "/_next/image"
to = "/.netlify/images?url=:url&w=:width&q=:quality"
status = 200

  [redirects.query]
  url = ":url"
  w = ":width"
  q = ":quality"

[[redirects]]
from = "/_ipx/*"
to = "/.netlify/images?url=:url&w=:width&q=:quality"
status = 200

  [redirects.query]
  url = ":url"
  w = ":width"
  q = ":quality"

[context]

  [context.production]

  [context.main]
2

That redirect seems to be coming from your code for the / page and not the middleware. As far as I can see, the middleware is working as expected and for the same request, this function: Function details | Functions | Logs | edgeless3-preview | Netlify also gets invoked (as expected due to rewrite()). The 308 comes from there.

These are the logs produced for a single request:

Netlify Edge Functions:

   ┌─message───────────────────────────────────┐
1. │ ===================================       │
2. │ Pathname: /                               │
3. │ Locale: en                                │
4. │ Languages: [ "en" ]                       │
5. │ Locales: [ "en", "de" ]                   │
6. │ Default Locale: en                        │
7. │ Is defaultLocale                          │
8. │ URL: https://preview.edgeless.systems/en/ │
   └───────────────────────────────────────────┘

---

Netlify Functions:

   ┌─message────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
1. │ REPORT RequestId: 33fb0aa5-a5a1-491f-8624-1ce2edfdd5c2     Duration: 104.72 ms     Billed Duration: 105 ms Memory Size: 1024 MB    Max Memory Used: 157 MB     │
   └────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

I also tried this in a minimal setup: hrishikesh-k/f-116856 (github.com), but going to the about URL: 662512f36e15edb636fb4784–f-116856.netlify.app/about/ loads the dashboard page without any redirect.

Mind sharing your repo so we can investigate further?

3

that’s weird as the problem happens with the index page only. I don’t have redirect rules anywhere in the project. I am not sure I can share the repo, but here is a zip with the code - WeTransfer - Send Large Files & Share Photos Online - Up to 2GB Free

The reasons I think this is Netlify issues are:

  1. No problem locally;
  2. No problem on Vercel - https://edgeless-systems-vbkq-gykvmx1xk-vladyslav-ls-projects.vercel.app
  3. Netlify just released a new Next.js Runtime;

However, thanks for your help, and I will be glad if there is an issue with my code :slight_smile:

4

Any updates @hrishikesh ? :slight_smile:

5

You’re right, I was able to reproduce this issue with your repo. Will check further and update.

7

I’ve escalated this to the devs. Thank you for sharing the code.

8

Okay, thanks for letting me know.
Will you be able to notify me once the issue is fixed?

9

Hi, I’ve subscribed to the issue. We will follow up here with an update from the devs when we have it. (:

10

This should be fixed in v5.2.2 of Next.js Runtime.

11

it works. Thanks a lot!