How to Create a Jest Snapshot Test in React

Learn how to create a Jest Snapshot test in React. Jest is built initially by Facebook to test React components. Now, even some Angular applications moved to Jest. When writing snapshot tests for a React component, you first need to have code in a working state. Jest, a testing framework, will compare the snapshot to the rendered output for the test.

Testing is crucial to maintaining any application!

Testing is a crucial pillar when it comes to building an application. Knowing how to code is important and knowing how to test what you have coded efficiently is crucial. Do you wonder why? Nowadays, computer science is used almost in every domain. Building an application needs many teams and collaborations, a lot of phases (developing phase, integration, production …etc.) a lot of resources. Thus a lot of money. Today, if you are looking for a developer post, you’ll notice that they’ll also ask you about your testing tools and skills.

Testing is the only way to be sure that we don’t break what we’ve built so far and, at the same time, the only way to make sure that the whole app is strong enough to be spread out to the world or its real users.

Enough blabla, let’s dive in following this plan:

• What’s Jest?
• Jest Test Example
• How to write a Jest snapshot Test?
• Takeouts

testing javascript react

Article covers: How native is react native?, React Native vs (Ionic, Cordova), Similarities and difference between React Native and Native App Development.

In this video I'll show you how to test react hooks using react-hooks-testing-library

Testing is complicated. I’ve certainly never been good at it. For the longest time, I’ve only been focused on basic function input-output unit tests. Why? Because they were easy — you didn’t need to render HTML, you didn’t need to query DOM elements, you didn’t need to interact with said DOM elements. But of course, React component testing is a necessity for any mature codebase. And it finally came time for me to sit down and figure it out. A window into React component testing. Interaction Testing with React Testing Library

When you want to test some of your React components using Jest unit testing, there are a few extra steps that should be taken to ensure proper testing is completed. I would suggest reading part one to the series here before continuing on so that you get the basic knowledge and learn how to set things up before moving forward with this article.

Test Driven Development (TDD) with React Test Renderer: Find out how to use React Test Renderer to test React components