- Implement integration tests for scanner vendor routing, ensuring correct routing to Alpha Vantage and fallback to yfinance.
- Create comprehensive unit tests for TTM analysis, covering metrics computation and report formatting.
- Introduce fail-fast vendor routing tests to verify immediate failure for methods not in FALLBACK_ALLOWED.
- Develop extensive integration tests for the yfinance data layer, mocking external calls to validate functionality across various financial data retrieval methods.