Testing React With Jest

The Big Mac index is a purchasing power parity index published by The Economist. Jest fetch testing is a tech task so frustrating that it almost made me quit the industry.

Snapshot tests are a common way to write lightweight component tests. When a snapshot test runs for the first time, it stores its output (e.g. rendered component’s HTML structure) in a snapshot output file.

If you are using Snapshot Tests with Jest for your components, there are a few pitfalls you have to be aware of.

Recently I have been expanding the codebase for my website and blog in order to have a more robust web presence. Part of this of course includes unit testing the source code using Jest.

In this React testing tutorial, we will introduce Enzyme in our Jest testing environment.

Jest got introduced by Facebook for testing JavaScript and especially React applications. It’s one of the most popular ways to test React components nowadays. Since it comes with its own test runner, you can simply call Jest from the command line to run all your tests.

I write tests because I want to be confident about two things: 1) That I didn’t break any existing code. (Existing tests to the rescue). 2)That my new code works as intended.

While it is important to have a well-tested API, solid test coverage is a must for any React application. Tests increase confidence in the code and helps prevent shipping bugs to users. That’s why we’re going to focus on testing in this post, specifically for React applications. By the end, you’ll be up and running with tests using Jest and Enzyme.

Today we are happy to announce the next major release of Jest - version 24! It's been 4 months since the last minor release, and 8 months since Jest 23, so this upgrade is a big one, with something for everyone!

Test your first React component using Jest and `react-testing-library`

When I started out writing tests for my React application, it took me some tries before I figured out how to set up my testing environment using Jest & Enzyme.

In this part, we'll finish the UI by adding the number and operator keys before we dive in to adding the basic calculator functionality.

In this post, we'll develop a React app using Test-Driven Development (TDD) with Jest and Enzyme.

Testing React components may be challenging for beginners as well as experienced developers who have already worked with tests. It may be interesting to compare your own approaches with the ones we use in our project. In order to cover the codebase, you have to know which components must be tested and which code exactly in the component should be covered.

Learn how to test React components using Jest and Enzyme

Reactjs is a UI library by facebook while Storybookjs is a testing tool for components by representing different states of the component and Jest is another cool unit testing tool by the creators of reactjs for javascript including reactjs.

In this post, we'll get a deeper understanding of testing components in React by writing more practical and realistic tests.

In this article, I will take you through everything that you need to know to write tests for your React components. I'll also cover some of the best practices and techniques while we're at it.

In this post I’d like to demystify some of these async patterns and highlight the traps that are hidden inside.

In this part we’ll cover some simple examples on how to test React components.

Learn how to install and setup Jest and Enzyme for testing React.

In this tutorial, we’ll see how to write tests for a React app using Jest and Puppeteer. Testing is an important part of modern web application development, it helps to check if the code you wrote is acceptable and works as accepted. It’s a way of catching bugs in your code before you go “live”.

How to use Puppeteer and Jest to perform End-to-End Testing on your React App

A React tutorial on how to setup and use React component tests with testing frameworks such as Mocha, Chai, Sinon, Enzyme and Jest.

I started to consider testing with Jest and Puppeteer right after the library came out. Puppeteer has quite an interesting API.

Recently, I joined Jest as a collaborator to help triage the issue tracker, and I’ve noticed a lot of questions about how mocking in Jest works, so I thought I would put together a guide explaining it.

In this post we’ll look at how to configure Visual Studio Code to debug React Components and Jest Unit Tests inside a web application that was created by create-react-app.

Writing unit & end-to-end tests to ship your mobile app with confidence.

Testing is a double-edged sword. On one hand, having a solid test suite makes code easier to refactor, and gives confidence that it works the way it should. On the other hand, tests must be written and maintained. They have a cost, like any other code.

Learn how to test React applications with the Jest JavaScript testing framework.

In this video, I answer the question, what is Jest?

In this video we'll cover how to test React components that contain asynchronous code using mocks in Jest. We'll refactor our component to make it more easily testable and mockable, allowing the test to run without making an actual AJAX request.

In this series, we'll cover the skills needed to understand the how and why of JavaScript testing.

In this video we talk about how to test components in React within create-react-app, how to configure Jest with Enzyme and Sinon, how to test with snapshots, simulate clicks, and interact with DOM elements through Enzyme.

In this post we’ll look at how to configure Visual Studio Code to debug React Components and Jest Unit Tests inside a web application that was created by create-react-app.

Dave Ceddia talks about using Jest's snapshot testing to verify your APIs are working as expected.

Jest has become one of the coolest things in testing JavaScript and React. In recent months, the Jest team has made huge strides with the testing framework and it's a pretty amazing tool.