# 2026-03-28 Q-004 Coverage Remediation Pass 24

## Scope

- Continue strict `Q-004` closure work after Pass 23.
- Fully close the breadcrumb-hook hotspot in:
  - `frontend/admin/src/lib/hooks/useBreadcrumbs.ts`
- Re-verify closure through targeted hook tests and full frontend validation.

## Changes

### Frontend

- Refined the hook implementation in:
  - `frontend/admin/src/lib/hooks/useBreadcrumbs.ts`
- Removed redundant parent-injection logic that was dead under the current route model and added closure-grade tests in:
  - `frontend/admin/src/lib/hooks/useBreadcrumbs.test.tsx`
- Newly verified behavior includes:
  - root-path empty breadcrumb output
  - single-segment terminal breadcrumb output
  - nested breadcrumb output for known child routes
  - skipping unknown route segments while retaining known ancestors

### Backend

- No backend code changes were required in this pass.

## Verified Commands

```powershell
cd D:\project\frontend\admin
npm.cmd run test:run -- src/lib/hooks/useBreadcrumbs.test.tsx
npm.cmd run lint
npm.cmd run build
npm.cmd run test:coverage
```

## Results

### Frontend coverage

- Overall:
  - statements `93.84%`
  - branches `82.29%`
  - functions `91.21%`
  - lines `94.01%`
- Target area:
  - `src/lib/hooks/useBreadcrumbs.ts`: statements `100%`, branches `100%`, functions `100%`, lines `100%`

### Validation outcomes

- Targeted hook validation passed:
  - `1` passing test file
  - `4` passing tests
- Full frontend coverage run now completes with:
  - `53` passing test files
  - `247` passing tests
- The required sequential frontend validation path passed:
  - `test:run -- src/lib/hooks/useBreadcrumbs.test.tsx`
  - `lint`
  - `build`
  - `test:coverage`

## Validation Notes

- The successful frontend coverage run still emits post-summary jsdom `AggregateError` network-noise lines.
  - The command exits with code `0`.
  - This remains a real validation-hygiene issue and cannot be hidden or described as a fully clean run.

## Real Conclusion

- `src/lib/hooks/useBreadcrumbs.ts` is no longer an open `Q-004` gap.
- `Q-004` still cannot be honestly declared closed.
- After this pass, the remaining higher-value frontend gaps narrow further to:
  - `src/app/providers/ThemeProvider.tsx`
  - the post-summary jsdom `AggregateError` coverage-noise hygiene issue
