https://frontendmasters.com/courses/intermediate-react-v2/redux-devtools/

Redux Devtools

You can install it for Chrome and Firefox.

It shows the Action, the State, Diff, etc. You can even scrub the timeline of changes to help you debug your code.

Transactional programming

This is called Transactional programming. You can replay the transactions and even skip some of them.

Unit test generation

There's even a test button that will create a unit test code for you (jest, mocha, tape, ava).