Configuring Vitest 4

This skill teaches correct Vitest 4.x configuration patterns, focusing on the breaking changes introduced in version 4.0.

Core Concepts

Vitest 4.0 introduced major configuration changes:

1. Pool Architecture: Consolidated pool configuration with maxWorkers
2. Coverage: Requires explicit include patterns
3. Multi-Project: Uses projects array instead of workspace
4. Dependencies: Moved under server.deps namespace

Quick Reference

Worker Configuration

import { defineConfig } from 'vitest/config';