When to use this skill

Use this skill whenever the user wants to:

Write unit tests and integration tests with Jest
Set up Jest in a project
Use Jest matchers and assertions
Test asynchronous code
Mock functions, modules, and dependencies
Create snapshot tests
Configure Jest for different environments
Use Jest with TypeScript, React, Vue, or other frameworks
Run tests and generate coverage reports
Use Jest CLI commands
Set up test environments (jsdom, node)
Use Jest with Vite (via vite-jest, though Vitest is recommended for new Vite projects)

How to use this skill

This skill is organized to match the Jest official documentation structure (https://jestjs.io/docs/getting-started, https://jestjs.io/docs/api). When working with Jest: