Configure Vitest with fork/thread pool isolation, mock lifecycle, fake timers, coverage gates, and CI-friendly concurrency. Use for unit and component tests in Vite/Next projects; diagnose parallel flakiness from shared module state.
Install
npx skills add alivirgo/Major-AI-Skills --skill vitestnpx skills add alivirgo/Major-AI-Skills --skill vitest -a claude-code -gnpx skills add alivirgo/Major-AI-Skills --skill vitest -a codex -ggemini skills install https://github.com/alivirgo/Major-AI-Skills.git --path skills/vitestgh skill install alivirgo/Major-AI-Skills vitestgit clone --depth 1 https://github.com/alivirgo/Major-AI-Skills /tmp/alivirgo__Major-AI-Skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/alivirgo__Major-AI-Skills/skills/vitest ~/.claude/skills/vitest # Claude Code
cp -R /tmp/alivirgo__Major-AI-Skills/skills/vitest ~/.agents/skills/vitest # Codex, Cursor, Gemini CLI, Copilot, OpenCode