Mark connect as deprecated #2264
Description
What is the new or updated feature that you are suggesting?
We're doing early collaboration with the React team on the design and behavior of the upcoming "concurrent stores" API. Loosely put, it's meant to be a concurrent compatible replacement for useSyncExternalStore.
This would likely ship as React-Redux v10, and also require a newer minimum version of React (unless they ship a polyfill for backwards compat with older versions).
Per discussion in #2263 (comment) , I don't intend to spend any time upgrading connect to use the new API, which means that it would still be using useSyncExternalStore and have its limitations with concurrent behavior like transitions.
We've said for years that useSelector ought to be the default, and that while we're not removing connect, we also recommend against using it.
Given that, we ought to do the same thing we did for createStore, and officially mark connect as @deprecated. As with createStore, we still have no plans to remove connect, but we really don't think anyone should be writing new code that uses it directly.
As with createStore, I'd probably ship an aliased version that doesn't have the deprecation, for folks who reallly don't want those deprecated strikethroughs in their codebase (or get flagged by enterprise linting requirements).
Once again, to be very clear: I do not intend to remove connect any time in the near future! It's possible we might remove it someday, but I have no plans to actually do so, and if we ever do it'd be a few years / major versions down the road.
Given that connect has a bigger bundle size, much more complex TS usage, worse re-rendering performance due to the tiered update cascading in the commit phase, and presumably won't have upcoming concurrent compat like useSelector, there's no good reason for people to still use it. Even the auto-wrapping-with-React.memo behavior is irrelevant now that the React Compiler exists.
I'll probably ship this deprecation in a new minor release in the next few weeks when I have time to do the work, and update the docs to cover this. (I might even rip out the ancient connect-based tutorial page while I'm at it.)
Why should this feature be included?
Because connect is obsolete :)
What docs changes are needed to explain this?
Release notes, removing some connect references, etc.