Add check for last seen vnode in index.js

[JoviDeCroock]

Resolves #589

TODO: add a test

[changeset-bot]

🦋 Changeset detected

Latest commit: c01b20d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@prefresh/core	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[NiedziolkaMichal]

It fixes the problem with infinite loop, but fragment content might not be rendered correctly:

Screen.Recording.2025-10-03.at.15.31.43.mov

[JoviDeCroock]

@NiedziolkaMichal That one component going away isn't really a prefresh bug, nor a general one. It's an issue when no parent-elements are present for ever-changing component identities. i.e. if you have any normal DOM node in your tree. i.e. wrap Layout with <main> that issue won't happen. It's a relic of using a really minimal example 😅 we should look for a fix for that at some point, I'll look at the Preact side when I have some time to figure that out.

EDIT: nvm, this is actually fixed in latest Preact, I just tried it locally.

Recording.2025-10-03.155445.mp4

[NiedziolkaMichal]

That's great to hear, thanks a lot for a quick fix