Prerender routes json

[colecrouter]

Problem

Prerendered pages on adapter-cloudflare should not require a worker request. See issue for more info #7298

Solution

Prerender pages as /foo/index.html instead of /foo.html, then exclude /foo in _routes.json. This will bypass the worker entirely, and still serve the prerendered page.

I ran the test suite, and tested it on my site with vite dev and deployed to Cloudflare Pages. I got the feeling that the change to packages/kit/src/core/prerender/prerender.js would cause more friction that it seemed to.

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[colecrouter]

Y'know, I suppose it would break the prerender tests, wouldn't it? haha

[colecrouter]

Not sure about that last test. I can't seem to get goto() to react to anything.

[Rich-Harris]

Thanks you but we can't just change about.html to about/index.html willy-nilly. One means /about, the other means /about/.

I'm also not sure this approach scales very far. There's quote a low limit to the number of entries you can have in your _routes.json (100 for include and exclude combined, IIUC) which many sites would immediately exceed.

[colecrouter]

Thanks you but we can't just change about.html to about/index.html willy-nilly. One means /about, the other means /about/.

That's what I've been alluding to in #7298 . I've got it working to Cloudflare's spec using wrangler, and vite dev the behavior seems to function identically, but I don't know what the exact expected behavior to start with (if different). /about still resolves correctly, and /about/index.html still 404s (when I was testing). Although I can't speak to /about vs /about/, Chrome usually changes that automatically 😅

The one failed test says something is wrong, but I can't seem to get it to work no matter what I do (I'm not too familiar with playwright, unfortunately). Aside from that, it seems to work fine for me "in practice".

I'm also not sure this approach scales very far. There's quote a low limit to the number of entries you can have in your _routes.json

~100 prerendered pages? How about adding a cap, or a switch + warning if over 100 entries. Then the worst case would be what's currently happening.

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[colecrouter]

Instead of automatically excluding prerendered pages, I've put in an adapter option that lets you manually specify if you want to bypass. That seems a lot safer. The Vite exports for prerendered pages are working properly now, so any prerendered test errors seem to be resolved (on my computer).

[Rich-Harris]

I merged #8422, which adds all assets and prerendered pages (up to the 100-rule limit), so I'll close this — thanks.

In general I think the automated approach is preferable to manually specifying exclusions, though in the rare cases that it is necessary it could be done by modifying the _routes.json after it's been created.

[colecrouter]

Bit late, but just wanted to say thanks. I just took a look at last month's bill, and we're down 85% on billed requests 😊(just from prerendered pages, alone). HUGE; thanks @Rich-Harris!