prerender when using hooks.server.js

Describe the bug

I'm not sure if this is a bug or not but I was confused by it so maybe we need a docs update.

The issue is that even though +layout.js exports export const prerender = false the build step will invoke hooks.server.js with the URL. If there is logic in the hooks.server.js#handle() function that is not prerenderable, (e.g. accessing event.url.search) the build will fail.

I assumed that since the layout disabled prerendering for its page tree, handle() would not even be invoked.

I think it's pretty common to have non-prerenderable code in hooks.server.js. In my case, I check auth and then redirect to /login?next=PATH_AND_SEARCH_OF_ORIGINAL_URL which breaks prerender.

The workaround is to check building in hooks.server.js before doing anything non-prerenderable. This probably deserves a mention in the docs since handle() will be invoked even for non-prerenderable URLs.

Reproduction

https://stackblitz.com/edit/sveltejs-kit-template-default-dapyhy?file=src/hooks.server.js

Run npm run build

Logs

No response

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (2) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 16.14.2 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 7.17.0 - /usr/local/bin/npm
  npmPackages:
    @sveltejs/adapter-node: latest => 1.2.4 
    @sveltejs/kit: ^1.5.0 => 1.17.0 
    svelte: ^3.54.0 => 3.59.1 
    vite: ^4.3.0 => 4.3.7

Severity

serious, but I can work around it

Additional Information

No response

sveltejs / kit