Unit tests are essential for increasing the test coverage of a backend application, ensuring its reliability, functionality, and robustness. Jest has become one of the most popular solutions when unit testing in Node, due to its intuitive API, zero-configuration philosophy, and flexible approach to code transpilation. In this guide, you will learn more about Jest, explore its features, and see it in action through a complete example. Become a Jest unit testing expert!

Node.js is a powerful runtime environment that allows you to handle asynchronous I/O operations efficiently using its event-driven architecture. Asynchronous operations in Node.js rely heavily on the event loop, and understanding how certain functions like process.nextTick() and setImmediate() interact with the event loop is essential for building fast, responsive applications.

When running tests, it's a great feeling to see dozens of green check marks indicating that a test suite is passing. It's especially gratifying after tackling a tricky bug or slogging through a tough feature. But those passing tests may be giving you a false sense of security. Often, bugs lurk in passing tests, undermining trust in the test suite and your application. Such tests can cause more harm than good, giving you a hearty pat on the back while hiding broken functionality.

Do you want the benefits of contract testing with much less effort? Are you convinced of the benefits of contract testing but think it’s just too difficult to roll out across your organization? You might worry that implementing Pact in your organization requires challenging changes to culture and process. In this article, I’ll show you a drastically simplified approach to contract testing that a single developer can bring online.

On October 29, 2024,* Node.js v22 officially transitioned into *Long Term Support (LTS) with the codename 'Jod'. For developers and organizations relying on the stability of Node.js for production environments, this transition marks a key milestone for Node.js 22.x, ensuring it will receive critical updates and security support for years to come. Let’s take a closer look at what this means, along with a refresher on the Node.js release lifecycle .

Testing is a critical aspect of software development, as it ensures your application works as intended and meets quality standards. In Node.js, testing is essential for the early detection of bugs in public endpoints. However, there are many challenges associated with testing in Node. External dependencies, asynchronous operations, and several possible input scenarios make writing tests a daunting task.

As a Node.js developer, you probably already know that testing code and maintaining its quality are essential aspects of software development, arguably just as important as writing code in the first place. Good tests raise confidence that changes won't cause problems, and the time invested eventually helps you ship faster.

When it comes to making HTTP requests in Node.js, developers are spoiled for choice: from the built-in and browser-familiar Fetch API to third-party libraries like Axios, Got, Superagent, Ky, and others. Navigating this diverse landscape can be a little daunting. This comprehensive guide aims to simplify your decision-making process by comparing the features and nuances of popular options, so you can select the ideal solution for your next project.

Jest and Vitest are two well-known JavaScript testing frameworks, each with its own strengths. Jest, created by Facebook, is especially popular for React applications. It provides a "zero-config" setup, built-in code coverage reporting, and snapshot testing, making it a complete solution for many JavaScript projects. Vitest, a newer framework in the Vite ecosystem, is known for its speed and lightweight design. Using Vite’s dev server, Vitest performs very well, especially in larger projects.

Error handling in Next.js is critical to providing a seamless experience to your users even when things go wrong. Without proper error management, users may get confused about what has happened and even leave your site. To avoid that, you must ensure that they receive informative feedback about errors and provide a way to recover from them. In this article, you'll see: Let's jump right in!