Using Redux Toolkit

Seven files hold the Redux code of the to-do app so far: actions.js, todosReducer.js, filterReducer.js, loadReducer.js, rootReducer.js, fetchTodos.js and store.js. Each action type is written twice, once in its action creator and once in a case of a reducer. Every reducer copies arrays and objects by hand to avoid changing the old state. The thunk dispatches its three actions by hand, and a separate reducer turns them into a status.

Redux Toolkit, the @reduxjs/toolkit package, writes most of that code for you. It is the official, recommended way to write Redux