When to Apply: Reference when testing Vite-based projects, preferring Vitest over Jest for ESM support, using vi.mock for module mocking, or leveraging in-source testing. Triggers on "Vitest", "vi.mock", "vi.fn", "Vite test", "vitest config".
Playbook Deep Dive (10 sections): §1 Production Configuration · §2 Mocking Patterns · §3 React Testing Library Integration · §4 Snapshot & Inline Snapshots · §5 Table-Driven & Parameterized Tests · §6 In-Source Testing · §7 API / Integration Testing · §8 CI/CD Integration · §9 Debugging Table · §10 Best Practices
The agent loads from 2 on-demand reference files (advanced-patterns.md, playbook.md) containing detailed implementation guides, cloud integration patterns, debugging tables, and language-specific best practices.