When to Apply: Reference when writing Ruby/Rails tests with RSpec, using FactoryBot for test data, or mocking HTTP requests with WebMock/VCR. Triggers on "RSpec", "expect().to eq()", "describe do", "Ruby test".
Playbook Deep Dive (11 sections): §1 Project Setup & Configuration · §2 Model & Service Tests · §3 Shared Examples & Contexts · §4 FactoryBot & Test Data · §5 HTTP Mocking with WebMock & VCR · §6 Request & Controller Tests (Rails) · §7 Time-Based Testing · §8 Custom Matchers · §9 CI/CD Integration · §10 Debugging Table · §11 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.