On that note, our new Redux Toolkit package is written in TS, and designed to work great in TS apps with a minimal amount of type declarations needed. Really just declare the type of the action in the reducer, and get everything else for free. The new React-Redux hooks API is also a lot easier to use with TS as well.
I showed how to use both of those in the Redux Toolkit "Advanced Tutorial" docs page:
https://redux-toolkit.js.org/tutorials/advanced-tutorial
On a related note, I also recently put up a long blog post detailing my own journey learning and using TS, as both a lib maintainer and an app developer, with my takeaways on the pros and cons of using TS:
https://blog.isquaredsoftware.com/2019/11/blogged-answers-le...