Latest version of Next.js is breaking this

[justincy]

I don't know what has changed in the last two months since I've been in this repo, but something is preventing our little hacks from working. It's somehow able to see past our rewrites and is returning a 308 redirect. I should be able to search their codebase for 308 and figure out what's going on.

[justincy]

v9.5.0 introduced the change. It was probably the trailing slash API changes.

[justincy]

When I ask for the home page / it's returning a redirect, presumably because it knows that page doesn't exist (all pages are inside the dynamic [locale] dir). But we have a rewrite middleware in place so that it thinks a different page is being requested. So that rewrite must not be working anymore which means they must've changed the logic for how they figure out which URL is being requested.

[justincy]

Here are two PRs that are related to the trailing slash changes:

• Prepare custom routes loading for adding additional routes vercel/next.js#13857
• Normalize trailing slashes vercel/next.js#13333

[justincy]

How would Next.js know to forward to /en?

[justincy]

Here's what I'm seeing:

logger: GET nexttest.com/
rewrite: GET nexttest.com/en/
logger: GET nexttest.com/en
rewrite: GET nexttest.com/en/en

[justincy]

Removing the trailing slash from the / rewrite (so that we get /en instead of /en/) seemed to make a difference. I accomplished that by modifying this line:

nextjs-domain-locales/server.js

Line 26 in 82b2a28

req.url = `/${locale}${req.url}`;

To be:

    req.url = `/${locale}${req.url}`.replace(/\/$/, '');

That avoids the redirect but for some reason the page doesn't render. The server sends the HTML but it doesn't hydrate and render. 😮

[justincy]

The body has the style display: none and the links trigger reloads (instead of a SPA navigation) so it's clear that Next isn't running and hydrating the UI.

[justincy]

I bet there's some other data on the front-end that checks URLs and known locations to see if it ought to run. We trim the locale so the path won't match. We try to fix that by modifying the path in the NEXT_DATA but apparently that's not good enough anymore.

Should we keep trying or give up on hacking?

[justincy]

We're going to leave this for now and try a different strategy that doesn't use the dynamic [locale] directory.