vitest

Automate unit testing for JavaScript and TypeScript projects with Vitest.

Updated Apr 12, 2026

Search Tags:#typescript #vitest #testing #mocking #unit-tests #react-testing

Ready to run

npx skills add https://github.com/gil00pita/lanify --skill vitest-gil00pita

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: vitest
Source: https://github.com/gil00pita/lanify/tree/main/.agents/skills/vitest
Command: npx skills add https://github.com/gil00pita/lanify --skill vitest-gil00pita

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Vitest provides a fast, integrated testing framework for JavaScript and TypeScript apps, including unit tests, mocking, and coverage, with React testing support.

Core Features & Use Cases

Native TypeScript and ESM support with Vite-powered speed for quick feedback
Suite includes unit tests, mocks, spies, timers, and coverage reporting
Built-in patterns for React testing and testing-library integration to validate UI components

Quick Start

Install vitest as a dev dependency and run tests with the vitest command.

Frequently Asked Questions about vitest

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I write unit tests for TypeScript apps using Vitest?▼

To write unit tests for TypeScript apps, Vitest provides native TypeScript support and Vite-powered speed for quick feedback. It automates testing across diverse codebases by handling configuration, setup, and the test environment directly.

What is the best way to mock dependencies in JavaScript unit tests?▼

Mocking dependencies in JavaScript unit tests is handled through Vitest's built-in suite, which includes mocks, spies, and timers. This allows you to isolate modules and validate interactions without relying on external systems.

Can I test React components with Vitest and testing-library?▼

Yes, you can test React components using Vitest. It provides built-in patterns for React testing and integrates with testing-library to validate UI components effectively within your JavaScript or TypeScript projects.

Does Vitest support ESM and Vite-based test environments?▼

Vitest natively supports ESM and leverages a Vite-based test environment. This integration delivers blazing-fast feedback for JavaScript and TypeScript apps by reusing your existing Vite configuration.

How do I measure code coverage in a Vite project?▼

Measuring code coverage in a Vite project is done using Vitest's built-in coverage reporting. You can install Vitest as a dev dependency, run tests with the vitest command, and generate coverage metrics automatically.

Do I need a specific framework to run unit tests for JavaScript and TypeScript?▼

You do not need multiple frameworks; Vitest provides an integrated testing framework for both JavaScript and TypeScript apps. It supports unit tests, mocking, and coverage natively, satisfying setup requirements without extra dependencies.