Is Redux startTransition compatible these days?

[einarq]

While trying to upgrade to React Router v7 I've started seeing some weird behavior in my tests (using createBrowserRouter).

I'm using loaders to initiate calls to queries as early as possible, as shown here:
TkDodo/blog-comments#84 (reply in thread)

I'm also using the loaders to dispatch some actions as early as possible, but I'm wondering if the conversion to "startTransition" under the hood in React Router is causing some timing issues for me.

Maybe the store isn't updated yet in some cases when the loader is triggered upon navigation?
I'm testing if using flushSync instead will solve it, but that feels like a potential de-optimization compared to v6.
remix-run/react-router#12855 (comment)

[markerikson]

I haven't actually tried investigating, but my understanding is that only React state is startTransition compatible, and nothing using useSyncExternalStore can be.

[einarq]

So I guess its fair to say that any apps using RR 7, and also using loaders to do early initiating of RTKQ and state, will not necessarily be compatible.

I havent been able to pinpoint anything yet, just seeing very odd failures in the test battery.

Might have to finally give replay a try :)

[einarq]

I guess this might potentially have an impact?

https://react.dev/blog/2025/04/23/react-labs-view-transitions-activity-and-more#concurrent-stores

[markerikson]

hopefully so, yes :) whenever that finally becomes a reality.