Jest is a JavaScript testing framework designed to ensure correctness of any JavaScript codebase. It allows you to write tests with an approachable, familiar and feature-rich API that gives you results …

Jul 12, 2025 · Jest is a JavaScript testing framework developed by Facebook, designed primarily for unit testing React applications. However, it can be used for testing any JavaScript codebase.

Feb 26, 2025 · Learn how to write effective tests with Jest. This guide covers Jest setup, test filtering, mocking, and coverage reporting to help you ensure your JavaScript code is fully tested, reliable, …

Apr 1, 2025 · In this Jest tutorial, we will learn about various Jest features, Jest matchers and how to use Jest framework for JavaScript Unit Testing.

You just successfully wrote your first test using Jest! This test used expect and toBe to test that two values were exactly identical. To learn about the other things that Jest can test, see Using Matchers.

Dec 13, 2025 · Supercharge your JavaScript code with confidence! This guided Code Lab will walk you through the essentials of unit testing using Jest.

Posted on May 20, 2025 • Edited on May 22, 2025. Jest is a fast, delightful JavaScript testing framework created at Meta. It can run out‑of‑the‑box, but real‑world projects (React, TypeScript, CSS modules, …

This tutorial covers everything you need to know about using Jest to test JavaScript, a simple and powerful testing framework. Whether you're a beginner or have some experience, this guide will help …

There are two ways to have Jest global APIs typed for test files written in TypeScript. You can use type definitions which ships with Jest and will update each time you update Jest.

Jan 22, 2026 · A product by Meta, Jest features extensive testing capabilities for JavaScript applications and those built with JavaScript frameworks. Let’s explore the Jest framework, its features, and how …