Reusing Reducer Logic As an application grows, common patterns in reducer logic will start to emerge. You may find several parts of your reducer

Implementing Undo History Building an Undo and Redo functionality into an app has traditionally required conscious effort from the developer

Beyond combineReducers The combineReducers utility included with Redux is very useful, but is deliberately limited to handle a

Prerequisite Reducer Concepts As described in Reducers, a Redux reducer function:

Isolating Redux Sub-Apps Consider the case of a “big” app (contained in a

Using Object Spread Operator Since one of the core tenets of Redux is to never mutate state, you'll often find yourself using

Reducing Boilerplate Redux is in part inspired by Flux, and the most

Writing Tests Because most of the Redux code you write are functions, and many of them are pure, they are easy to test without mocking.

Refactoring Reducer Logic Using Functional Decomposition and Reducer Composition It may be helpful to see examples of what the different types

Using combineReducers Core Concepts The most common state shape for a Redux app is a plain Javascript object