Book Image

React Design Patterns and Best Practices. - Second Edition

Book Image

React Design Patterns and Best Practices. - Second Edition

Overview of this book

React is an adaptable JavaScript library for building complex UIs from small, detached bits called components. This book is designed to take you through the most valuable design patterns in React, helping you learn how to apply design patterns and best practices in real-life situations. You’ll get started by understanding the internals of React, in addition to covering Babel 7 and Create React App 2.0, which will help you write clean and maintainable code. To build on your skills, you will focus on concepts such as class components, stateless components, and pure components. You'll learn about new React features, such as the context API and React Hooks that will enable you to build components, which will be reusable across your applications. The book will then provide insights into the techniques of styling React components and optimizing them to make applications faster and more responsive. In the concluding chapters, you’ll discover ways to write tests more effectively and learn how to contribute to React and its ecosystem. By the end of this book, you will be equipped with the skills you need to tackle any developmental setbacks when working with React. You’ll be able to make your applications more flexible, efficient, and easy to maintain, thereby giving your workflow a boost when it comes to speed, without reducing quality.
Table of Contents (19 chapters)
Free Chapter
1
Section 1: Hello React!
4
Section 2: How React works
9
Section 3: Performance, Improvements and Production!

Painless JavaScript testing with Jest

The most important way to learn how to test React components in the right way is by writing some code, and that is what we are going to do in this section.

The React documentation says that at Facebook they use Jest to test their components. However, React does not force you to use a particular test framework, and you can use your favorite one without any problems.

To see Jest in action, we are going to create a project from scratch, installing all the dependencies and writing a component with some tests. It'll be fun!

The first thing to do is to move into a new folder and run the following:

  npm init

Once package.json is created, we can start installing the dependencies, with the first one being the jest package itself:

  npm install --save-dev jest

To tell npm that we want to use the jest command to run the tests, we have to add the...