Vitest (Testing Framework)

Overview

Vitest is a blazing fast unit test framework powered by Vite. Native TypeScript support, ESM by default, Jest-compatible API, and instant watch mode.

Version: v2.x (2024-2025)
Requirements: Node ≥18

Key Benefit: Zero config for TypeScript, uses Vite's transform pipeline, 10-20x faster than Jest.

When to Use This Skill

✅ Use Vitest when:

• Testing TypeScript code (tRPC, Zod, utilities)
• Working with Vite-based projects
• Need fast watch mode during development
• Want native ESM support
• Testing React components (with @testing-library)