App router middleware rewrites not working with i18n enabled

[mparisot-antescofo]

Hello,

I'm trying to do rewrites through my middleware to App router pages cohabiting with page router pages

I made a repo reproducing the issue : https://github.com/mparisot-antescofo/netlify
with a separate branch to add i18n to it : mparisot-antescofo/netlify#4

On the main branch all is behaving as expected:
rewrite to app router page : https://antescofo-test-netlify-rewrites.netlify.app/rewrite-app
redirect to app router page : https://antescofo-test-netlify-rewrites.netlify.app/redirect-app
rewrite to page route page : https://antescofo-test-netlify-rewrites.netlify.app/rewrite-page
redirect to page router page : https://antescofo-test-netlify-rewrites.netlify.app/redirect-page

But on the branch https://deploy-preview-4--antescofo-test-netlify-rewrites.netlify.app which add the i18n config, the rewrite to app router page returns a 404 while all the others work as expected : https://deploy-preview-4--antescofo-test-netlify-rewrites.netlify.app/rewrite-app

I tried to disable the language detection or forcing the url.locale before the rewrite thinking it might be the issue but I have the same results

Note that I added an additional app subdirectory to be able to separate page and app routed pages in other places of my code

thank you

[serhalp]

Hi @mparisot-antescofo!

Though this isn't documented, I believe Next.js itself does not really support i18n when mixing App Router and Pages Router: vercel/next.js#57704 (comment). 😞

Hope that link helps.

[mparisot-antescofo]

I think it is a different issue and the one you linked was part of the reason I had to add a subdirectory to distinguish between app and page router pages

In my case everything works fine in dev and build mode if I run things locally, it only fails when I deploy to netlify

The page also works fine if I call it directly, it only returns a 404 when I try to create a rewrite in my middleware and deploy it on netlify hence why I suspect it is an issue on your side

For now I changed my rewrite into a redirect as a workaround even though I would prefer not to expose those urls to the user