restate VS redux-xstate-poc

One quality about state machines that I find overlooked is debuggability. Limiting state updates to transitions makes it so easy to debug weird edge cases and race conditions. This upside is perhaps more relevant on the backend though where state is more long-lived, which is why I've been experimenting with a project for building backends with state machines: https://github.com/fabianlindfors/restate.

Very doable, but not the most ideal syntax, since `createSlice` is focused on "here's an action / thing that happened, here's the reducer that handles that".

On the flip side, you can also use XState state machines as Redux reducers. A state machine is, after all, a function that takes a current state value + some event, and returns a new state.... exactly the same as a reducer function!

David and I have been saying for a while that we'd like to have a more official integration between XState and Redux. A while back, Matt Pocock put together an proof of concept for what a `createXStateSlice` might look like [1]. I actually sat down with David a couple weeks ago and we did some further design discussions about the possibility of using the `@xstate/fsm` package (a smaller version of XState's logic) as a starting point, and generating RTK actions based on that. No code yet, but it seems feasible.

[0] https://dev.to/davidkpiano/redux-is-half-of-a-pattern-1-2-1h...

[1] https://github.com/mattpocock/redux-xstate-poc

Fun fact: one of the XState devs did a proof-of-concept showing how to use XState state machines as Redux reducers and integrate the side effects handling as a middleware:

https://github.com/mattpocock/redux-xstate-poc

We'd like to work together to turn that into a more official integration sometime soon.

One of the XState devs recently posted https://github.com/mattpocock/redux-xstate-poc , an example of how you can integrate XState into a Redux app for use as a Redux slice reducer + side effects middleware