Regression Test Suite: Automated execution integrated into workflow

Summary

Establish a systematic regression testing approach integrated into the epic workflow, with automated execution on PRs and clear criteria for test coverage.

Problem

Current state:

• Regression testing mentioned but not enforced
• "All existing tests continue to pass" is the only check
• No baseline regression suite defined
• No automated regression execution
• Reactive approach (catch regressions after they occur)
• No regression metrics tracked

From QA analysis: Regression Testing scored 4.5/10 (Critical Gap)

Proposed Solution

1. Regression Impact Analysis in Planning

Add to /create-epic-plan:

### Regression Impact Analysis

Identify existing features at risk:

| Existing Feature | Risk | Affected Flows | Regression Tests |
|------------------|------|----------------|------------------|
| [feature] | [H/M/L] | [flows] | [existing tests] |

**Regression Test Plan:**
- [ ] Baseline: Run full suite before epic, capture results
- [ ] Per-ticket: Run affected tests on each PR
- [ ] Pre-completion: Full regression before epic closure

2. Regression Requirements in Implementation Plan

Add to /generate-implementation-plan:

#### Regression Tests Required
- **Existing tests to run:** [list test files/suites]
- **New regression tests to add:** [describe coverage gaps]
- **Critical paths to protect:** [list user flows]

3. Automated Execution Strategy

On PR creation:
  → Run affected regression tests (< 5 min)

On PR merge to main:
  → Run full regression suite (< 30 min)

Nightly:
  → Run extended regression suite
  → Generate coverage report

4. Regression Metrics in Retrospective

Add to /complete-sprint:

### Regression Testing Metrics
- **Suite Size:** [count]
- **Execution Time:** [minutes]
- **Pass Rate:** [%] (target: 100%)
- **Regressions Caught Pre-Production:** [count] ✓
- **Regressions Escaped:** [count] ✗ (target: 0)
- **Flaky Tests:** [count] (target: < 5%)

5. Regression Failure Protocol

• Failure detected → Block PR merge
• Triage: Real regression vs flaky test
• Real regression → Fix required before proceeding
• Flaky test → Stabilize and track

Acceptance Criteria

• Regression impact analysis added to epic planning
• Regression test requirements in implementation plans
• Clear criteria for which tests constitute regression suite
• Automated execution integrated into PR workflow
• Regression metrics tracked in sprint retrospective
• Failure protocol documented

Related

• Supports Quality Gates improvements
• Integrates with CI/CD pipeline