headquarter/openspec/changes/notification-center/apply-progress.md

Apply Progress: PR-1 Backend Core for Notification Center

TDD Cycle Evidence

Cycle	Task	Test File	RED	GREEN	Evidence
1	NC-PR1-004 (basic CRUD)	tests/unit/test_notification_service.py	13 tests written against missing service	All 13 pass	pytest tests/unit/test_notification_service.py → 13 passed
2	NC-PR1-005 (edge cases)	tests/unit/test_notification_service.py	Already included in cycle 1	Added wrong-owner, mute-categories, cross-user isolation	Same 13 tests pass
3	NC-PR1-007 (basic endpoints)	tests/integration/test_notifications_api.py	10 tests written against missing router	All 10 pass	pytest tests/integration/test_notifications_api.py → 10 passed
4	NC-PR1-008 (API edge cases)	tests/integration/test_notifications_api.py	Already included in cycle 3	Pagination, 404 ownership, mute categories at API layer	Same 10 tests pass
5	NC-PR1-010 (REFACTOR)	All files	—	ruff clean, no regressions	ruff check passes on all new files; existing unit tests 223 passed (4 pre-existing failures unrelated)

Completed Tasks

• NC-PR1-001: Alembic migration for notifications table
• NC-PR1-002: SQLAlchemy Notification model (apps/api/src/models/notification.py)
• NC-PR1-003: Export Notification in models/__init__.py
• NC-PR1-004: NotificationService unit tests — basic CRUD (RED)
• NC-PR1-005: Implement NotificationService singleton (GREEN)
• NC-PR1-006: Service edge-case and isolation tests (TRIANGULATE)
• NC-PR1-007: API integration tests — basic endpoints (RED)
• NC-PR1-008: Implement FastAPI router + Pydantic schemas (GREEN)
• NC-PR1-009: API edge-case and ownership tests (TRIANGULATE)
• NC-PR1-010: Register router in main.py + import Notification for Alembic
• NC-PR1-011: Code quality pass — ruff, test regressions, smoke tests (REFACTOR)

Files Changed

1. apps/api/alembic/versions/2026_05_29_add_notifications_table.py (new) — Alembic migration
2. apps/api/src/models/notification.py (new) — SQLAlchemy model
3. apps/api/src/models/__init__.py — Export Notification
4. apps/api/src/services/notification_service.py (new) — NotificationService singleton
5. apps/api/src/api/notifications.py (new) — FastAPI router + Pydantic schemas
6. apps/api/src/api/__init__.py — Export notifications_router
7. apps/api/src/main.py — Register router, import Notification for Alembic
8. apps/api/tests/unit/test_notification_service.py (new) — 13 unit tests
9. apps/api/tests/integration/test_notifications_api.py (new) — 10 integration tests
10. apps/api/tests/integration/test_models.py — Updated expected tables list

Test Commands & Exit Codes

# Unit tests for NotificationService (13 tests)
cd apps/api && python -m pytest tests/unit/test_notification_service.py -v
# Exit: 0 — 13 passed

# Integration tests for notifications API (10 tests)
cd apps/api && python -m pytest tests/integration/test_notifications_api.py -v
# Exit: 0 — 10 passed

# Combined new tests
cd apps/api && python -m pytest tests/unit/test_notification_service.py tests/integration/test_notifications_api.py -v
# Exit: 0 — 23 passed

# Existing unit tests (no regressions in our code)
cd apps/api && python -m pytest tests/unit/ -v
# Exit: 1 — 223 passed, 4 failed (pre-existing failures in test_config.py and test_git_repository_clone_preflight.py)

# Ruff linting on all new/modified files
cd apps/api && python -m ruff check \
  src/models/notification.py \
  src/models/__init__.py \
  src/services/notification_service.py \
  src/api/notifications.py \
  src/api/__init__.py \
  src/main.py \
  alembic/versions/2026_05_29_add_notifications_table.py \
  tests/unit/test_notification_service.py \
  tests/integration/test_notifications_api.py \
  tests/integration/test_models.py
# Exit: 0 — All checks passed

# Smoke tests
health: 200
notifications unauth: 401

Deviations from Design

• SQLAlchemy metadata column name conflict: Base.metadata is reserved by SQLAlchemy DeclarativeBase. Used notification_metadata as the Python attribute name with DB column name "metadata". In the Pydantic response model, used Field(serialization_alias="metadata") so the JSON API still exposes metadata as specified.
• created_at type in Pydantic: Used datetime instead of str to leverage FastAPI's automatic ISO serialization.

Surprises / Decisions

1. SQLite func.now() resolution: test_list_notifications_orders_by_created_at_desc failed because multiple rapid INSERTs got identical timestamps. Fixed by explicitly setting created_at offsets in the test after creation.
2. Pre-existing integration test failures: ~40 integration tests fail due to missing asyncpg module and direct PostgreSQL connection attempts in their custom setup code. These are unrelated to our changes.
3. Pre-existing test_models.py outdated: The test_expected_tables_are_registered assertion had a hardcoded set missing many newer tables. Updated it to include all current tables (including notifications).

Remaining Tasks

None — PR-1 is complete.

PR Boundary

This PR covers PR-1 only (NC-PR1-001 through NC-PR1-011). PR-2 (backend integration) and PR-3/PR-4 (frontend) are out of scope.