tests

Tests — Architecture & Patterns

Overview: Test architecture for api-observatory uses a three-layer strategy (unit, integration, e2e) with shared fixtures and selectable database modes.

Fixture strategy:

• Layer 1 (shared): fixtures_shared.py — database mode selection (aiosqlite in-memory vs. PostgreSQL)
• Layer 2 (unit): tests/unit/conftest.py — unit test marker, lightweight mocks
• Layer 3 (integration): tests/integration/conftest.py — full app context, real database
• Custom fixtures: reusable factories in tests/shared/factories.py

Test hierarchy (quick):

tests/
  ├─ conftest.py          # Global: database mode, asyncio_mode=auto
  ├─ fixtures_shared.py   # Database fixture selection
  ├─ unit/
  ├─ integration/
  ├─ e2e/
  └─ shared/

When to write each type:

• Unit: single function/method, no I/O — fast
• Integration: API routes, DB round-trips — medium
• E2E: full workflows — slow, CI-only or nightly

Fixture patterns:

• Database mode controlled by PYTEST_DB_MODE (default: aiosqlite)
• Run integration against Postgres: PYTEST_DB_MODE=postgres pytest tests/integration/

Coverage expectations:

• Local: pytest tests/unit/ tests/integration/ --cov
• CI gate: 80% coverage on modified files (unit + integration)