unit-test

unit-test

Testing patterns for the Python/FastAPI + React/TypeScript stack. Covers pytest configuration, conftest fixtures, database safety guards, external API mocking, async tests, Celery eager mode, and Vitest for frontend.

1) pytest Configuration

# pytest.ini
[pytest]
testpaths = tests
addopts = -v --tb=short
markers =
    db: Database integration tests (require TEST_DATABASE_URL)
    unit: Pure unit tests (no DB, no network)
    celery: Celery task tests
    slow: Tests that call mocked external APIs
    asyncio: Async tests (pytest-asyncio)

# pyproject.toml alternative
[tool.pytest.ini_options]
testpaths = ["tests"]
addopts = "-v --tb=short"
asyncio_mode = "auto"   # for pytest-asyncio: auto-detect async test functions
markers = [
    "db: Database integration tests",
    "unit: Pure unit tests",
    "slow: Mocked external API tests",
]

[tool.coverage.run]
source = ["app", "shared", "api"]
omit = ["tests/*", "*/migrations/*"]

[tool.coverage.report]
show_missing = true
fail_under = 70

2) conftest.py — Session Fixtures + DB Safety Guard

# tests/conftest.py
import os
import pytest
from database.connection import ThreadedConnectionPool
from database.adapters.psycopg2_adapter import Psycopg2Adapter

# ── Safety guard ──────────────────────────────────────────────────────────
@pytest.fixture(scope="session", autouse=True)
def require_test_database():
    url = os.environ.get("TEST_DATABASE_URL", os.environ.get("DATABASE_URL", ""))
    if not url:
        pytest.fail("DATABASE_URL or TEST_DATABASE_URL must be set to run tests")
    if "test" not in url:
        pytest.fail(
            f"Refusing to run tests against non-test database.\n"
            f"URL must contain 'test': {url}"
        )

# ── Connection pool (session-scoped — created once) ───────────────────────
@pytest.fixture(scope="session")
def db_pool(require_test_database):
    url = os.environ["TEST_DATABASE_URL"]
    pool = ThreadedConnectionPool(minconn=1, maxconn=5, dsn=url)
    yield pool
    pool.closeall()

# ── Per-test DB adapter (auto-cleanup after each test) ────────────────────
@pytest.fixture
def db(db_pool):
    adapter = Psycopg2Adapter(db_pool)
    yield adapter
    # Cleanup: delete all rows in reverse FK order
    for table in ["sends", "prospects", "campaigns", "tenants", "users"]:
        adapter.execute_raw(f"DELETE FROM {table}")
    adapter.close()

# ── Domain fixtures ───────────────────────────────────────────────────────
@pytest.fixture
def sample_tenant(db):
    return db.insert("tenants", {"name": "Test Tenant", "domain": "test.example.com"})

@pytest.fixture
def sample_campaign(db, sample_tenant):
    return db.insert("campaigns", {
        "tenant_id": sample_tenant["id"],
        "name": "Test Campaign",
        "status": "active",
    })

@pytest.fixture
def sample_prospects(db, sample_campaign):
    prospects = [
        {"campaign_id": sample_campaign["id"], "email": f"lead{i}@example.com", "status": "new"}
        for i in range(3)
    ]
    return [db.insert("prospects", p) for p in prospects]