Forwarded event fetch request having double headers in Nuxt/SEO module (triggered in server middleware)

[Xenossolitarius]

Environment

node 20
mac m3

Reproduction

Connected all the dots

Describe the bug

On the receiving API
Invalid URL

at new URL (node:internal/url:806:29)
at getRequestURL (/XXX/node_modules/.pnpm/h3@1.13.1/node_modules/h3/dist/index.mjs:337:10)
at Object.handler (server/middleware/01.auth.ts:8:1)
at /XXX/node_modules/.pnpm/h3@1.13.1/node_modules/h3/dist/index.mjs:1963:31
at async Object.callAsync (/XXX/node_modules/.pnpm/unctx@2.4.1/node_modules/unctx/dist/index.mjs:72:16)
at async toNodeHandle (/XXX/node_modules/.pnpm/h3@1.13.1/node_modules/h3/dist/index.mjs:2255:7)
at async ufetch (/XXX/node_modules/.pnpm/unenv@1.10.0/node_modules/unenv/runtime/fetch/index.mjs:9:17)
at async $fetchRaw2 (/XXX/node_modules/.pnpm/ofetch@1.4.1/node_modules/ofetch/dist/shared/ofetch.03887fc3.mjs:258:26)
at async $fetchRaw2 (/XXX/node_modules/.pnpm/ofetch@1.4.1/node_modules/ofetch/dist/shared/ofetch.03887fc3.mjs:311:14)
at async $fetch2 (/XXX/node_modules/.pnpm/ofetch@1.4.1/node_modules/ofetch/dist/shared/ofetch.03887fc3.mjs:316:15)

Breaks with

while using event as a fetchContainer

on

getRequestURL

where the vars are:

the double "localhost:3000, localhost:3000" shouldn't be there I guess

Also this error only happens in nuxt server middleware when getRequestURL is called

https://github.com/unjs/h3/pull/946/files

I believe the change above introduced such issue

Not really sure if this is the upstream issue but tnx again for taking a look!

Additional context

Logs

[harlan-zw]

On my end it looks like it's caused by a workaround I did for the bug fixed in: #946

I can remove my workaround but that will break earlier versions so probably better to merge them correctly.

[harlan-zw]

Actually I think this is a bug purely on the Sitemap module using defu to merge the headers now that I'm looking into the h3 source.

Will move discussion to nuxt-modules/sitemap#400

[Xenossolitarius]

Yea, sorry couldn't debug it properly. Goes too deep into some very internal logic there

[harlan-zw]

I'm not convinced of my above point either now actually, no idea 🤷

Will track in sitemap for now

[Xenossolitarius]

Ok, i'll try to debug it today and will report the results.

[harlan-zw]

This would likely fix it but I'm concerned it may introduce regressions nuxt-modules/sitemap#402

[Xenossolitarius]

I ve tracked the headers joined by defu and it's simple:

{
   Accept: "application/json",
   Host: "localhost:3000"
}

So i don't really see an issue here with this. I'll try to track whats happening on the h3 side

[Xenossolitarius]

@harlan-zw OK i think i've found what the issue is

Headers are both capitalized Host and lowercase host

As you can see the new h3 addition getProxyRequestHeaders return the lowercase localhost and yours event fetch init code adds the capitalized Host.

It's a giant side effect of the whole pipeline. Now not sure if sitemap module needs uppercase Host or should the h3 change the logic regarding the joining of headers for the host parameter.

Hope this helps

[Xenossolitarius]

Fixed downstream