vitest

Run Jest-compatible unit tests for Vite projects with ESM, TypeScript, and JSX support.

2.5k|134|Updated Mar 28, 2026
One-click install
npx skills add https://github.com/compozy/compozy --skill vitest-compozy
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: vitest
Source: https://github.com/compozy/compozy/tree/main/.agents/skills/vitest
Command: npx skills add https://github.com/compozy/compozy --skill vitest-compozy

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

Vitest provides fast, Jest-compatible unit testing for Vite projects, enabling rapid feedback during development.

Core Features & Use Cases

  • Jest-compatible API with native ESM, TypeScript, and JSX support.
  • Vite-native transformation with smart watch mode for selective re-runs.
  • Built-in coverage, multi-threaded workers, and snapshot/mocking utilities.

Quick Start

Create a test file and run the vitest CLI to execute the tests.

Frequently Asked Questions about vitest

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

FAQPage Schema
How do I run unit tests for a Vite project using a Jest-compatible API?

You can run unit tests for a Vite project by creating a test file and executing the vitest CLI, which provides a Jest-compatible API with native ESM, TypeScript, and JSX support for rapid feedback.

Does Vitest work with native ESM and TypeScript out of the box?

Yes, Vitest works with native ESM and TypeScript out of the box by leveraging Vite-native transformation, allowing you to write tests without heavy configuration setup.

What is the best way to get built-in code coverage in Vite testing?

The best way to get built-in code coverage in Vite testing is using Vitest, which includes coverage tools alongside snapshot and mocking utilities natively without requiring additional heavy setup.

Can I use smart watch mode to selectively re-run Vite unit tests?

Yes, you can use smart watch mode to selectively re-run Vite unit tests, as Vitest integrates Vite-native transformation to monitor changes and execute only the affected test files.

How does Vitest handle parallel execution for testing?

Vitest handles parallel execution for testing by utilizing multi-threaded workers, running multiple test files concurrently to provide fast feedback during development.

Do I need Jest to set up multi-project configurations with Vitest?

No, you do not need Jest to set up multi-project configurations, as Vitest supports optional multi-project configurations natively without heavy setup while maintaining Jest-compatible syntax.