is there a way to know if the request was triggered by a preload in a hook?

[PierBover]

I have an error hook that checks if there's been an auth error in which case the user is redirected to the login page:

import {goto} from '$app/navigation';
// custom error
import {NotAuthentincatedError} from '$lib';

export async function handleError({error}) {
	if (error instanceof NotAuthentincatedError) {
		goto('/login');
		return;
	}

	// etc
}

This works great except that links with the data-sveltekit-preload-data option will also trigger this hook. This is fine but it's a bit weird in terms of UX that a user hovers a link and ends up in a login page.

Ideally I would like to know if the request was triggered by a preload so that this logic can be ignored... is there a way to accomplish this?

[Antoine-lb]

I think the header Sec-Fetch-Mode: navigate is what you are looking for