Introduction

In this lesson, we discuss the basics of Reducers and their importance in Redux.

In computer science, the word reducer is commonly associated with a function that takes an array or object and converts it to a simpler structure. E.g, summing all the items in an array.

In Redux, the role of the reducer is somewhat different: reducers create a new state out of the old one, based on an action.

In essence, a reducer is a simple JavaScript function that receives two parameters (two objects—the previous state and an action) and returns an object (a modified copy of the first argument):

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Introduction to Redux

Basic Redux Implementation

Cloning a Redux Boilerplate

Complete Redux Project

Creating a Store

Decorating the Store

Actions and Action Creators

Redux Thunk

Redux-Actions Library

Reducers

Avoiding Mutations

Introduction to Middleware

Your First Middleware

Middleware

State Management

Keeping a Normalized State

Persistence State

Real-World State

Server Communication

Moving Code from Action Creators

Error Handling

Server Communication II

Transforming Data

Chaining Requests

Managing Side Effects

Messaging Patterns

WebSockets

WebSocket Authentication

Testing

Testing Action Creators

Async Action Creators

Testing Reducers

Testing Middleware

Testing Async Middleware

Integration Tests

Evolution Of Redux

Final Assessment

Introduction