Phase 3 Delta Comparison Engine Plan¶
Strategy (WHY)¶
QA teams need side-by-side comparison of two runs (reliability + performance) with deterministic regression/improvement labels — especially for load and multi-stage cycles.
Implementation (HOW — use these as source of truth)¶
| Layer | Detail |
|---|---|
| Metric semantics | Delta Comparison Policy |
| Core service | testo_core/services/delta_service.py |
| CLI | Command Reference § testo diff / testo summary |
| API | GET /api/v1/analytics/delta |
| React | frontend/src/features/compare/ |
Do not duplicate the direction table here — it lives in Delta Comparison Policy.
Release gate¶
Release Checklist - Phase 3 Delta Engine
Context & Links: Delta Comparison Policy, Architecture Overview, Product Roadmap § Phase 3: Enterprise UI & Analytics