Jest

What is it?

Jest is an open-source JavaScript testing framework originally developed by Meta (Facebook). It is designed to work out of the box with minimal configuration and strong defaults for modern JavaScript projects.

What does it do?

Jest enables unit, integration, and snapshot testing for JavaScript and TypeScript code. It includes built-in assertions, test runners, code coverage, mocking, and parallel test execution.

Where is it used?

Jest is widely used in frontend applications (React, React Native, Vue), backend services (Node.js), and full-stack projects that require fast, reliable automated testing.

When & why it emerged

Jest was introduced in 2014 to simplify JavaScript testing and reduce configuration complexity. It emerged as an alternative to fragmented testing stacks by providing an all-in-one testing solution.

Why we use it at Internative

We use Jest to ensure code quality and reliability across frontend and backend systems. Its speed, clear error reporting, and seamless integration with modern frameworks support scalable and maintainable testing practices.