fastapi基于pytest的异步测试（tortoise-orm）

1. 前情提要：

- fastapi官方文档只给了普通异步请求demo，没有orm数据库读写的示例

- 而tortoise-orm的文档还停留在同步版的测试范例

2. 需求：

单元测试函数不仅能通过HTTP请求访问API，还能读写数据库

3. 实现：

- 安装依赖：pip install httpx fastapi tortoise-orm pytest

- 在tortoise-orm范例的基础上，引入httpx并把测试函数改成异步，并配置好pytest使其在执行测试函数之前，配置好数据库连接，执行完测试之后关闭数据库连接，关键代码如下：

- conftest.py

import pytest
from httpx import AsyncClient
from tortoise import Tortoise

from main import app

DB_URL = "sqlite://:memory:"


async def init_db(db_url, create_db: bool = False, schemas: bool = False) -> None:
    """Initial database connection"""
    await Tortoise.init(
        db_url=db_url, modules={"models": ["models"]}, _create_db=create_db
    )
    if create_db:
        print(f"Database created! {db_url = }")
    if schemas:
        await Tortoise.generate_schemas()
        print("Success to generate schemas")


async def init(db_url: str = DB_URL):
    await init_db(db_url, True, True)


@pytest.fixture(scope="session")
def anyio_backend():
    return "asyncio"


@pytest.fixture(scope="session")
async def client():
    async with AsyncClient(app=app, base_url="http://test") as client:
        print("Client is ready")
        yield client


@pytest.fixture(scope="session", autouse=True)
async def initialize_tests():
    await init()
    yield

- tests/test_users.py

import pytest
from httpx import AsyncClient

from models.users import User


@pytest.mark.anyio
async def test_testpost(client: AsyncClient):
    name, age = ["sam", 99]
    assert await User.filter(username=name).count() == 0

    data = {"username": name, "age": age}
    response = await client.post("/testpost", json=data)
    assert response.json() == dict(data, id=1)
    assert response.status_code == 200

    response = await client.get("/users")
    assert response.status_code == 200
    assert response.json() == [dict(data, id=1)]

    assert await User.filter(username=name).count() == 1

完整Demo见：

python - Testing in FastAPI using Tortoise-ORM - Stack Overflow