This repository was just a fun session live coding the Redux store from scratch. If you want to learn more about Redux, check out the official site as well as the amazing tutorial, Getting Started with Redux, from Dan Abramov.
The project uses yarn, but you should be fine if you're using npm. For tests, it uses jest. One other thing to note is that the project is using node 14.0.0. I opted for this so that ES modules could be used with out any compilation step.