# 2026-03-28 Q-004 Coverage Remediation Pass 20

## Scope

- Continue strict `Q-004` closure work after Pass 19.
- Fully close the remaining high-risk storage hotspot in:
  - `frontend/admin/src/lib/storage/token-storage.ts`
- Re-verify closure through targeted storage tests and full frontend validation.

## Changes

### Frontend

- Added dedicated storage coverage in:
  - `frontend/admin/src/lib/storage/token-storage.test.ts`
- Newly covered behavior includes:
  - in-memory refresh token read/write
  - blank and `undefined` normalization to `null`
  - explicit token clearing
  - presence checks for the in-memory token
  - session presence cookie detection
  - the no-`document` fallback branch

### 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/storage/token-storage.test.ts
npm.cmd run lint
npm.cmd run build
npm.cmd run test:coverage
```

## Results

### Frontend coverage

- Overall:
  - statements `92.32%`
  - branches `79.63%`
  - functions `89.70%`
  - lines `92.49%`
- Target area:
  - `src/lib/storage/token-storage.ts`: statements `100%`, branches `100%`, functions `100%`, lines `100%`

### Validation outcomes

- Full frontend coverage run now completes with:
  - `50` passing test files
  - `229` passing tests
- The required sequential frontend validation path passed:
  - `test:run -- src/lib/storage/token-storage.test.ts`
  - `lint`
  - `build`
  - `test:coverage`

## Validation Notes

- The successful frontend coverage run still emits one post-summary jsdom `AggregateError` network-noise line.
  - It does not fail the command.
  - It remains a real validation-hygiene issue and cannot be hidden.

## Real Conclusion

- `src/lib/storage/token-storage.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/lib/errors/AppError.ts`
  - `src/pages/admin/ImportExportPage/ImportExportPage.tsx`
  - `src/pages/NotFoundPage/NotFoundPage.tsx`
  - the post-summary jsdom `AggregateError` coverage-noise hygiene issue
