Testing

pytest + pytest-asyncio + in-memory SQLite + httpx.AsyncClient.

Why AsyncClient instead of TestClient?

fastapi.testclient.TestClient is synchronous — it does not support async with. To test async endpoints painlessly, use httpx.AsyncClient(transport=ASGITransport(app=app)), which mounts the app over ASGI in the same event-loop as your tests. The examples below follow that pattern.

Shared fixtures

# tests/conftest.py
from collections.abc import AsyncGenerator

import pytest_asyncio
from httpx import ASGITransport, AsyncClient
from sqlalchemy.ext.asyncio import AsyncSession

from tempest_fastapi_sdk import AsyncDatabaseManager, BaseModel

import src.db.models  # noqa: F401 — side-effect: registers every model on BaseModel.metadata
from src.api.app import create_app


@pytest_asyncio.fixture
async def db() -> AsyncGenerator[AsyncDatabaseManager, None]:
    """Fresh in-memory DB per test."""
    manager = AsyncDatabaseManager("sqlite+aiosqlite:///:memory:")
    await manager.connect()
    await manager.create_tables(BaseModel.metadata)
    try:
        yield manager
    finally:
        await manager.drop_tables(BaseModel.metadata)
        await manager.disconnect()


@pytest_asyncio.fixture
async def session(db: AsyncDatabaseManager) -> AsyncGenerator[AsyncSession, None]:
    """Managed session bound to the in-memory DB."""
    async for s in db.session_dependency():
        yield s


@pytest_asyncio.fixture
async def client(db: AsyncDatabaseManager) -> AsyncGenerator[AsyncClient, None]:
    """ASGI-backed async client with the prod DB swapped for the in-memory one."""
    app = create_app()
    # Override the session dependency to use the test DB.
    from src.api.app import db as production_db

    app.dependency_overrides[production_db.session_dependency] = db.session_dependency

    async with AsyncClient(
        transport=ASGITransport(app=app),
        base_url="http://test",
    ) as client:
        yield client

Repository test

# tests/repositories/test_user.py
import pytest
from sqlalchemy.ext.asyncio import AsyncSession

from src.core.exceptions import UserNotFoundError
from src.db.models import UserModel
from src.db.repositories import UserRepository


class TestUserRepository:
    async def test_get_by_email_raises_when_missing(
        self, session: AsyncSession
    ) -> None:
        repo = UserRepository(session)
        with pytest.raises(UserNotFoundError):
            await repo.get({"email": "ghost@example.com"})

    async def test_add_and_get(self, session: AsyncSession) -> None:
        repo = UserRepository(session)
        user = await repo.add(
            UserModel(
                email="ana@example.com",
                name="Ana",
                hashed_password="<bcrypt-hash>",
            )
        )
        loaded = await repo.get_by_id(user.id)
        assert loaded.email == "ana@example.com"

BaseUserModel columns

The abstract BaseUserModel declares email, hashed_password, is_active, is_admin, name and last_login_at. The non-default fields (email + hashed_password) are nullable=False, so omitting either one raises IntegrityError on flush. Also note: the column is hashed_password — not password_hash.

Endpoint test

# tests/api/test_users.py
from httpx import AsyncClient


class TestUsersAPI:
    async def test_signup(self, client: AsyncClient) -> None:
        response = await client.post(
            "/auth/signup",
            json={
                "email": "ana@example.com",
                "password": "strong-pass-12-chars",
                "name": "Ana",
            },
        )
        assert response.status_code == 201, response.text
        body = response.json()
        assert "user_id" in body
        # The activation link is only present when AUTH_RETURN_TOKEN_IN_RESPONSE=true
        # or no EmailUtils is wired — typical for the test environment.
        assert body["activation_required"] in {True, False}

    async def test_get_user_not_found(self, client: AsyncClient) -> None:
        response = await client.get(
            "/api/users/00000000-0000-0000-0000-000000000000",
        )
        assert response.status_code == 404
        body = response.json()
        # SDK envelope is always {detail, code, details}. The `code` value
        # is set by your project's UserNotFoundError subclass — use whichever
        # constant your project chose (see Tutorial §5).
        assert "code" in body

About the code field on the error envelope

The SDK serializes every AppException as {detail, code, details}. The exact code value depends on the domain subclass your project defines — UserNotFoundError(NotFoundException, code="USER_NOT_FOUND") is just a tutorial convention. See tutorial §5 to create your own subclasses.

Helpers from tempest_fastapi_sdk.testing

tempest_fastapi_sdk.testing provides framework-agnostic helpers that don't require pytest to be importable — wrap them in @pytest.fixture inside the consuming project's conftest.py. Useful when a test doesn't need a full AsyncDatabaseManager (no lifespan, no health-check probes).

Helper	Signature	Purpose
create_test_engine	(database_url="sqlite+aiosqlite:///:memory:", *, echo=False) -> AsyncEngine	Build a throwaway AsyncEngine (StaticPool when in-memory).
create_test_session_factory	(engine) -> async_sessionmaker[AsyncSession]	Build a sessionmaker bound to the engine (expire_on_commit=False).
init_test_metadata	async (engine, metadata=None) -> None	Create every table (defaults to BaseModel.metadata).
drop_test_metadata	async (engine, metadata=None) -> None	Drop every table.
test_database	async (database_url=..., *, metadata=None) -> AsyncIterator[async_sessionmaker[AsyncSession]]	Async context manager — yields a session factory with metadata pre-created, drops + disposes on exit.
test_session	async (database_url=..., *, metadata=None) -> AsyncIterator[AsyncSession]	Async context manager — yields one AsyncSession on top of a fresh test_database.

# tests/conftest.py
from collections.abc import AsyncGenerator

import pytest_asyncio
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker

from tempest_fastapi_sdk.testing import test_database, test_session


@pytest_asyncio.fixture
async def session_factory() -> AsyncGenerator[async_sessionmaker[AsyncSession], None]:
    """Yield a session factory backed by a fresh in-memory DB per test."""
    async with test_database() as factory:
        yield factory


@pytest_asyncio.fixture
async def session() -> AsyncGenerator[AsyncSession, None]:
    """Yield a single AsyncSession backed by a fresh in-memory DB."""
    async with test_session() as s:
        yield s

Use the test_session() context manager for ad-hoc tests that don't need a shared fixture:

from tempest_fastapi_sdk.testing import test_session

from src.db.models import UserModel
from src.db.repositories import UserRepository


async def test_repo_directly() -> None:
    async with test_session() as session:
        repo = UserRepository(session)
        await repo.add(
            UserModel(
                email="ana@example.com",
                name="Ana",
                hashed_password="<bcrypt-hash>",
            )
        )
        assert await repo.count() == 1

Pass metadata= when your project mixes the SDK's BaseModel.metadata with a second isolated metadata (rare — keep one BaseModel per service whenever possible).