cookies.delete() throws "response has been generated" error in +layout.server.ts

[Nintron27]

I have a logout route that in the load function deletes an account token cookie and redirects back to the root /. However, every once in a while my layout throws the following error:

Error: Cannot use `cookies.set(...)` after the response has been generated

This is because (to my knowledge what's happening) is:

1. The /logout load deletes the cookie and redirects to /
2. The layout then tries to ALSO delete the cookie (when / is loading), because it's still set sometimes (not sure why, but I see it clearly when I console log the cookies.get on the account token. (The reason that the layout ALSO tries to delete the cookie is the layout will fetch the customer information associated with the cookie, and if null is returned than the cookie expired so layout will delete it.)

Deleting a cookie though shouldn't have this happen? It seems somehow it's almost like the cookies.delete in the layout.server.ts is running after the return statement, despite the fact that it very much isn't after that statement, or in any sort of Promise.

I couldn't reproduce this yet outside of my own codebase, which I can't share (so I didn't file a bug report), but it's basically this system here. (Go to /login, then /logout)

[matmoxam]

This sounds similar to this issue that also is difficult to reproduce. The load function on +layout.server and +page.server.ts seems to be called on a client side fetch for some reason during dev mode: https://stackoverflow.com/questions/78206769/layout-svelte-ts-and-page-server-ts-are-executed-twice-after-a-fetch-is-done