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.