(docs): update i18n-routing.md

[ehowey]

The recommended code for _middleware.ts does not work in prod, but does work locally. You need to use request.nextUrl.pathname to properly redirect from what I can tell. You also need to have a quick helper function to strip off the /default locale at the start of the pathname as we are providing /en as a fallback locale.

FWIW - I am pretty new to NextJS. Someone with more experience should probably review this suggestion before merging it. What I can tell you however is that the code as it is in _middleware.ts works locally but breaks in prod. To test this out use the code and navigate to https//www.mysite.com - it will work as expected on the root url, as this matches nextUrl.href. Now try navigating to https//www.mysite.com/about and you will be redirected to https://www.mysite.com/en/https://www.mysite.com/about.

Documentation / Examples

• Make sure the linting passes by running yarn lint

Closes: #33762

[ehowey]

I was having trouble finding the related issue unfortuntately but there is a long discussion of this - having read that I think probably the correct fix would be without the stripDefaultLocale function I have in my code.

Maybe just pointing out this error in the docs so someone else can toss the fix in there.

[ijjk]

Thanks for the PR!

[ehowey]

Thanks for the PR!

No problem - I am not sure how resilient that stripDefaultLocale function I put in there is. I wanna take another quick look at this and see if I have some cleaner code. I have been working with middleware quite a bit the last month!

[ijjk]

Instead of using a regex we could do str === '/default' ? '/' : str.startsWith('/default/') ? str.substr(8) : str which is similar to the locale cleaning we do in the client router here although the regex is alright besides the pathname edge case of /default-some-value instead of /default/some-value