Book Image

Learning Redux

By : Daniel Bugl
Book Image

Learning Redux

By: Daniel Bugl

Overview of this book

The book starts with a short introduction to the principles and the ecosystem of Redux, then moves on to show how to implement the basic elements of Redux and put them together. Afterward, you are going to learn how to integrate Redux with other frameworks, such as React and Angular. Along the way, you are going to develop a blog application. To practice developing growing applications with Redux, we are going to start from nothing and keep adding features to our application throughout the book. You are going to learn how to integrate and use Redux DevTools to debug applications, and access external APIs with Redux. You are also going to get acquainted with writing tests for all elements of a Redux application. Furthermore, we are going to cover important concepts in web development, such as routing, user authentication, and communication with a backend server After explaining how to use Redux and how powerful its ecosystem can be, the book teaches you how to make your own abstractions on top of Redux, such as higher-order reducers and middleware. By the end of the book, you are going to be able to develop and maintain Redux applications with ease. In addition to learning about Redux, you are going be familiar with its ecosystem, and learn a lot about JavaScript itself, including best practices and patterns.
Table of Contents (13 chapters)

Making functions pure

Before we learn how to make generic abstractions for our reducers, we will take a closer look at pure functions. We have already learned a bit about them in the previous chapters. Pure functions have no side effects; they always return the same output, given the same input. The following is what makes Redux so predictable:

  • Reducers take the current state and an action and return the new state
  • All reducers are pure functions
  • Given the same input, pure functions return the same output
  • As a result, given the same state and action, reducers will always return the same new state

When writing abstractions on top of our reducers, we need to make sure that they are also pure functions, otherwise we will lose the benefits of Redux and introduce unpredictable behavior.

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