# Incident Post-Mortem: Developer Agent Not Testing UI Code After Fixes

**Date:** 2025-01-27
**Severity:** P1 (High - Affects Quality Gate)
**Author:** Forensic Engineer
**Story ID:** N/A (System-wide issue)

## Executive Summary

Developer agent does not automatically test UI code after fixes, despite rules requiring Playwright verification. Root cause: workflow treats testing as separate phase, missing automatic trigger mechanism for frontend code changes.

## Timeline of Events

| Time (UTC) | Event | Actor | Impact |
|------------|-------|-------|--------|
| System Design | Workflow defined: Developer → PR Reviewer → Tester | Architecture | Testing isolated to Phase 6 |
| Rule Creation | `implementation.md` line 48: "Frontend: You **MUST** use Playwright MCP" | Rules | Rule exists but not enforced in fix workflow |
| Current State | Developer fixes UI code, no automatic testing | Developer Agent | UI changes not verified before PR |

## Root Cause

**The Single Change:** Workflow architecture separates testing into Phase 6 (Verification), requiring manual phase progression. Developer agent lacks automatic trigger for UI testing after fixes.

### 5 Whys Analysis

1. **Why** doesn't developer test UI after fixes?
   - Testing is defined as separate phase (Phase 6: Verification), not part of developer's fix workflow.

2. **Why** is testing a separate phase?
   - Workflow design follows sequential SDLC: Implementation → Review → Verification.

3. **Why** doesn't developer agent trigger testing automatically?
   - No detection logic for frontend code changes.
   - No automatic call to `execute_frontend_tests()` or `check_testing_capabilities()` after fixes.

4. **Why** isn't the Playwright rule enforced in fix workflow?
   - Rule exists in "Verification" section (line 44-53) for initial implementation.
   - "Verification After Fixes" section (line 288-294) only says "Run tests" without UI-specific instruction.

5. **Why** (ROOT CAUSE): Workflow assumes manual phase progression. Developer agent completes fixes, expects Tester phase to handle verification. No automatic quality gate for UI changes.

## Contributing Factors

| Category | Factor | How It Contributed |
|----------|--------|-------------------|
| **Method** | Sequential workflow design | Testing isolated to separate phase, not integrated into fix cycle |
| **Method** | Missing frontend detection | No logic to identify UI code changes and trigger appropriate testing |
| **Method** | Incomplete rule enforcement | Playwright rule exists but not referenced in "after fixes" workflow |
| **Machine** | No automatic test trigger | `execute_frontend_tests()` tool exists but not called automatically |
| **Measurement** | No capability check in fix flow | `check_testing_capabilities()` only runs on Tester agent activation |

## Impact Assessment

- **Quality Risk:** High - UI changes not verified before PR submission
- **Regression Risk:** Medium - UI bugs may reach PR review phase
- **Developer Experience:** Low - Manual testing required or bugs discovered later
- **Workflow Efficiency:** Medium - Additional cycle if bugs found in Tester phase

## Evidence

### Code References

**Workflow Structure:**
```254:255:src/sef_agents/constants.py
    "developer": "pr_reviewer",
    "pr_reviewer": ["tester", "security_owner"],  # Parallel
```

**Developer Rule (Initial Implementation):**
```48:52:src/sef_agents/rules/development/implementation.md
-   **Frontend**: You **MUST** use Playwright MCP to verify the UI.
    -   Navigate to the local dev server (e.g., `http://localhost:3000`).
    -   Interact with your specific change.
    -   Capture a screenshot.
    -   Generate `sef-reports/qa_lead/ui_test_report.md`.
```

**Developer Rule (After Fixes):**
```288:294:src/sef_agents/rules/development/implementation.md
### 4. Verification After Fixes
After fixing all issues:
- ✅ Run linter (must pass: 0 errors, 0 warnings)
- ✅ Run type checker (must pass)
- ✅ Run tests (must pass)
- ✅ Verify no regressions introduced
- ✅ Confirm all review comments addressed
```

**Missing:** No explicit UI testing instruction in "Verification After Fixes" section.

## Preventative Actions

| # | Action | Owner | Priority | Due Date | Ticket |
|---|--------|-------|----------|----------|--------|
| 1 | Add frontend detection logic to developer agent | Developer | P0 | - | - |
| 2 | Update "Verification After Fixes" to explicitly require Playwright for UI code | Rules | P0 | - | - |
| 3 | Add automatic `check_testing_capabilities()` call after UI fixes | Developer | P1 | - | - |
| 4 | Add automatic `execute_frontend_tests()` trigger for frontend changes | Developer | P1 | - | - |
| 5 | Create workflow hook: detect frontend keywords → trigger UI testing | Workflow | P1 | - | - |

## Recommended Fixes

### Fix 1: Update Developer Rules (Immediate)

**File:** `src/sef_agents/rules/development/implementation.md`

**Change:** Update "Verification After Fixes" section (line 288-294) to include:

```markdown
### 4. Verification After Fixes
After fixing all issues:
- ✅ Run linter (must pass: 0 errors, 0 warnings)
- ✅ Run type checker (must pass)
- ✅ Run tests (must pass)
- ✅ **For UI/Frontend changes**: Run `check_testing_capabilities()` and `execute_frontend_tests(story_id)` if Playwright available
- ✅ Verify no regressions introduced
- ✅ Confirm all review comments addressed
```

### Fix 2: Add Frontend Detection (High Priority)

**File:** `src/sef_agents/rules/development/implementation.md`

**Add:** New section after "Verification After Fixes":

```markdown
### 5. Frontend Code Detection (MANDATORY)
After fixing issues, check if changes involve frontend code:
- Scan changed files for frontend keywords: `ui`, `component`, `page`, `button`, `form`, `react`, `vue`, `angular`, `frontend`, `css`, `styling`
- If frontend code detected:
  1. Run `check_testing_capabilities(story_id)` to verify Playwright availability
  2. If available: Run `execute_frontend_tests(story_id)`
  3. If unavailable: Document manual testing steps in `sef-reports/qa_lead/ui_test_report.md`
  4. Log to TECH_DEBT.md if E2E deferred
```

### Fix 3: Workflow Integration (Medium Priority)

**Consider:** Adding automatic test trigger in workflow state machine when developer marks artifact complete for frontend stories.

## Lessons Learned

1. **Rule Location Matters:** Rules in "Verification" section don't automatically apply to "fix" workflows.
2. **Workflow Gaps:** Sequential phases create blind spots between agent transitions.
3. **Tool Availability:** Tools exist (`execute_frontend_tests`) but aren't automatically invoked.
4. **Detection Logic:** Frontend keyword detection should trigger different verification paths.

## Appendix

- **Workflow Definition:** `src/sef_agents/constants.py:248-262`
- **Developer Rules:** `src/sef_agents/rules/development/implementation.md`
- **Testing Tools:** `src/sef_agents/tools/browser/test_executor.py`
- **Frontend Keywords:** `src/sef_agents/constants.py:265-284`
