test:fixture

Command /test:fixture

Create a pytest fixture for tests.

Instructions

Step 1: Determine fixture type

• session — AsyncSession for database operations
• client — AsyncClient for API testing
• db — full test database setup
• mock — mock for a dependency
• sample — test data (sample user, sample order, etc.)

Step 2: Determine scope

• function (default) — created for each test
• class — created for each test class
• module — created for each module
• session — created once for the entire test session

Step 3: Determine location

• Shared fixtures → tests/conftest.py
• Module-specific fixtures → tests/modules/{module}/conftest.py
• Local fixtures → in the test file itself

Fixture Templates

AsyncSession with rollback (recommended)

# tests/conftest.py
import pytest
from collections.abc import AsyncGenerator
from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker

from src.core.database import Base


@pytest.fixture(scope="session")
def engine():
    """Test engine — created once."""
    return create_async_engine(
        "postgresql+asyncpg://test:test@localhost:5432/test_db",
        echo=False,
    )


@pytest.fixture(scope="session")
async def setup_database(engine):
    """Create tables before tests."""
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)
    yield
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)


@pytest.fixture
async def session(
    engine,
    setup_database,
) -> AsyncGenerator[AsyncSession, None]:
    """Session with automatic rollback after each test."""
    async with engine.connect() as connection:
        await connection.begin()
        session_maker = async_sessionmaker(
            bind=connection,
            expire_on_commit=False,
        )
        async with session_maker() as session:
            yield session
        await connection.rollback()