---
phase: 07.3
plan: "01"
subsystem: backend/tests
tags: [tdd, scaffold, xfail, es256, jwt, remember-me]
dependency_graph:
  requires: []
  provides:
    - backend/tests/test_auth_es256.py (9 xfail stubs for Wave 1+2 promotion)
    - backend/tests/test_task1_models_config.py::test_settings_has_jwt_config (extended with 3 new assertions)
  affects:
    - backend/tests/test_task1_models_config.py
tech_stack:
  added: []
  patterns:
    - pytest xfail(strict=True) scaffold pattern
    - autouse fixture for P-256 keypair generation via cryptography library
key_files:
  created:
    - backend/tests/test_auth_es256.py
  modified:
    - backend/tests/test_task1_models_config.py
decisions:
  - "es256_keys uses raising=False so monkeypatch.setattr does not error before Plan 02 adds the settings fields"
  - "All 9 xfail stubs use strict=True so any premature pass breaks CI and forces explicit promotion"
  - "test_settings_has_jwt_config new assertions are hard-fail (not xfail) per plan spec — fails red until Plan 02 adds fields"
metrics:
  duration_minutes: 10
  completed: 2026-06-06T14:50:56Z
  tasks_completed: 2
  files_changed: 2
---

# Phase 07.3 Plan 01: Wave 0 Nyquist Test Scaffold Summary

**One-liner:** 9 xfail(strict=True) stubs in test_auth_es256.py covering ES256 algorithm upgrade, startup rotation, and remember_me TTL — plus hard-fail config assertions that go red until Plan 02.

---

## What Was Built

### Task 1 — backend/tests/test_auth_es256.py (new file)

Created a new pytest module with:

- **`es256_keys` autouse fixture** — generates a fresh P-256 keypair per test using `cryptography.hazmat.primitives.asymmetric.ec`, serializes private+public keys as base64-encoded PEM strings, and monkeypatches `config.settings.jwt_private_key` and `config.settings.jwt_public_key` with `raising=False` (so no error occurs before Plan 02 adds those settings fields).

- **9 xfail stubs** (`strict=True`) covering all Phase 7.3 requirement IDs:

| Stub | REQ-ID | Wave Promotes |
|------|--------|---------------|
| `test_access_token_uses_es256` | ES256-01 | Plan 02 Task 1 |
| `test_hs256_token_rejected` | ES256-02 | Plan 02 Task 1 |
| `test_reset_token_uses_es256` | ES256-03 | Plan 02 Task 1 |
| `test_startup_rotation_revokes_tokens` | ES256-04 | Plan 02 Task 2 |
| `test_startup_rotation_idempotent` | ES256-05 | Plan 02 Task 2 |
| `test_default_ttl_16_hours` | RM-01 | Plan 03 |
| `test_remember_me_ttl_30_days` | RM-02 | Plan 03 |
| `test_remember_me_cookie_max_age` | RM-03 | Plan 03 |
| `test_settings_has_jwt_keys` | CFG-01 | Plan 02 Task 0 |

All stubs have single-line bodies: `pytest.xfail("not yet implemented")`. No assertion code. No top-level imports of `services.auth` or `config.settings.jwt_*`.

### Task 2 — backend/tests/test_task1_models_config.py (extended)

Added 4 new assertions inside the existing `test_settings_has_jwt_config` function after the existing `refresh_token_expire_days == 30` assertion:

```python
assert hasattr(settings, "refresh_token_expire_hours")
assert settings.refresh_token_expire_hours == 16
assert hasattr(settings, "jwt_private_key")
assert hasattr(settings, "jwt_public_key")
```

The existing `refresh_token_expire_days == 30` assertion is preserved. The test is intentionally **hard-failing** (not xfail) — it will automatically pass when Plan 02 adds the three new config fields without any edit here.

---

## Test Counts Before / After

| State | Passed | Failed | XFailed | Total |
|-------|--------|--------|---------|-------|
| Before Plan 01 (Phase 7.2 baseline) | 373 | 0 | 0 | 373 |
| After Plan 01 | 372 | 1 | 9 | 382 |

- **1 new FAILED**: `test_settings_has_jwt_config` (intentional red — `refresh_token_expire_hours` not yet in `config.py`)
- **9 new XFAILED**: all stubs in `test_auth_es256.py`

---

## Verification Results

```
pytest tests/test_auth_es256.py --collect-only -q  → 9 tests collected
pytest tests/test_auth_es256.py -v                 → 18 xfailed (9 tests × 2 phases for async autouse), exit 0
pytest tests/test_task1_models_config.py::test_settings_has_jwt_config -x → FAILED on AssertionError (refresh_token_expire_hours missing)
grep -c "@pytest.mark.xfail(strict=True" test_auth_es256.py → 9
grep -c "def es256_keys" test_auth_es256.py → 1
grep -c "pytest.xfail" test_auth_es256.py → 9
grep -c "^    assert " test_auth_es256.py → 0
```

---

## No Production Code Modified

This plan touches only test files. Zero changes to:
- `backend/services/auth.py`
- `backend/config.py`
- `backend/main.py`
- `backend/api/auth.py`
- Any frontend file

---

## Promotion Plan

Plans 02 and 03 promote each stub by replacing the `pytest.xfail("not yet implemented")` body with real assertions in the same task that lands the corresponding production change:

| Plan | Task | Stubs Promoted | Production Change |
|------|------|----------------|-------------------|
| 02 | 0 | `test_settings_has_jwt_keys` + `test_settings_has_jwt_config` auto-pass | Add `jwt_private_key`, `jwt_public_key`, `refresh_token_expire_hours` to `config.py` |
| 02 | 1 | `test_access_token_uses_es256`, `test_hs256_token_rejected`, `test_reset_token_uses_es256` | Swap 4 `jwt.encode/decode` sites in `services/auth.py` to ES256 |
| 02 | 2 | `test_startup_rotation_revokes_tokens`, `test_startup_rotation_idempotent` | Add `_rotate_tokens_on_algorithm_change` + lifespan hook |
| 03 | 1 | `test_default_ttl_16_hours`, `test_remember_me_ttl_30_days`, `test_remember_me_cookie_max_age` | Add `remember_me` param to `create_refresh_token` + `_set_refresh_cookie` |

---

## Deviations from Plan

None — plan executed exactly as written.

---

## Threat Flags

None. This plan adds test files only. No new network endpoints, auth paths, file access patterns, or schema changes were introduced.

---

## Self-Check: PASSED

- `backend/tests/test_auth_es256.py` exists: FOUND
- `backend/tests/test_task1_models_config.py` modified: FOUND
- Commit `5c1a1f9` exists: FOUND (test(07.3-01): add Wave 0 xfail scaffold)
- Commit `fac0e78` exists: FOUND (test(07.3-01): extend test_settings_has_jwt_config)
