Redux vs MobX (Learn Both!)

Source code: https://github.com/ZeroCho/redux-vs-mobx/blob/master/5.react-redux-toolkit/store.js

In the redux-toolkit tutorial

The way to import getDefaultMiddleware has changed. You should use it as a function instead of an array. And you can write the middleware you want to add inside concat.

middleware : ( getDefaultMiddleware ) => getDefaultMiddleware ( ) . concat ( logger )