afterNavigate is called for destroyed route if transitions are present

[Rich-Harris]

Describe the bug

An afterNavigate callback should only run if the component in question is still active. If a page has an afterNavigate callback and also contains transitions, then the page's effects (including the one responsible for afterNavigate) are not destroyed until after transitions have finished, but the afterNavigate callback will run as soon as the navigation completes.

The result is that the callback might error, since it could refer to data that no longer exists.

To be honest I'm not sure what the correct behaviour is here — obviously we don't want to run the afterNavigate callbacks if we've already navigated away, but that can only happen if effect teardown runs before transitions complete. Which maybe is the correct thing to do, in which case this is a Svelte bug?

Unfortunately I don't have any time to spend on this right now, so will come back to it later

Reproduction

https://github.com/Rich-Harris/kit-after-navigate-timing

Logs

No response

System Info

latest

Severity

annoyance

Additional Information

No response