fetch passed to load function in +page.server.js implements CORS

[Theo-Steiner]

Describe the bug

Even though it will only ever run on the server, the fetch implementation that is passed to load in +page.server.js is checking for CORS, behaving as if it were called in a browser.

I assume this might be an oversight from when +page.server routes were first introduced, since obviously you'd very much want this behavior in non-server page.js load function, but it doesn't really make any sense in the new environment.

I hope I didn't overlook an issue where this was discussed already and kept for technical reasons, but even then we'd probably want this documented.

Reproduction

https://stackblitz.com/edit/sveltejs-kit-template-default-52u2qj?file=src%2Froutes%2F%2Blayout.svelte,src%2Froutes%2F%2Bpage.svelte,src%2Froutes%2F%2Bpage.server.js&terminal=dev

Logs

No response

System Info

stackblitz

Severity

annoyance

The global fetch correctly doesn't implement CORS, so one can simply use that. However it is a bit confusing getting a CORS error from a request you make on the server.

Additional Information

No response

[pheuter]

Some discussion here for additional context: https://discord.com/channels/457912077277855764/1035096174014771231/1035096174014771231