testing-patterns

Test coverage enforcement uses pytest, vitest, and Pester with strict thresholds set to 90% or higher. Run pytest --cov --cov-fail-under=90 for backend, vitest run --coverage --coverage.thresholds.lines=90 for frontend, and Invoke-Pester with CodeCoverageOutputFileThreshold 90 for infrastructure code to gate releases on quality metrics.

Idempotency testing ensures operations produce the same result when repeated; rollback testing verifies state recovery after failures. These patterns, enforced by this Skill, prevent data corruption and enable safe deployments by confirming code can be safely re-executed or reverted without side effects.

Correlation ID isolation testing tags requests with unique identifiers to track them across backend, frontend, and infrastructure components. This pattern ensures tests remain independent, enables debugging of distributed failures, and supports CAB-ready governance by providing full request traceability.

Yes. The Skill codifies testing patterns for these three ecosystems and applies coverage gates and mandatory test types retroactively. Integrate pytest, vitest, and Pester into your CI pipeline, set thresholds to 90%, and structure tests as unit, integration, and end-to-end layers matching EUCORA's architecture.

The testing pyramid layers isolate concerns: unit tests verify individual functions without dependencies, integration tests confirm components work together, and end-to-end tests validate complete user workflows. This Skill enforces all three levels across your stack to ensure CAB-ready code quality.

All three layers are mandatory under EUCORA standards this Skill enforces. The 90% coverage gate across unit, integration, and end-to-end tests cannot be met by skipping layers; the structured pyramid ensures gaps in any tier block deployment, prioritizing quality over schedule pressure.