使用 pytest 的异步装置

Question

如何定义异步装置并在异步测试中使用它们？

下面的代码，都在同一个文件中，失败得很惨。 fixture 是否由测试运行器明确调用而不等待？

 @pytest.fixture
async def create_x(api_client):
    x_id = await add_x(api_client)
    return api_client, x_id

async def test_app(create_x, auth):
    api_client, x_id = create_x
    resp = await api_client.get(f'my_res/{x_id}', headers=auth)
    assert resp.status == web.HTTPOk.status_code

生产

==================================== ERRORS ====================================
_____________ ERROR at setup of test_app[pyloop] ______________

api_client = <aiohttp.test_utils.TestClient object at 0x7f27ec954f60>

    @pytest.fixture
    async def create_x(api_client):
>       x_id = await add_x(api_client)
...
... cannot show the full trace and pathnames sorry
...

in __await__
    ret = yield from self._coro /home/mbb/.pyenv/versions/3.6.3/envs/mr/lib/python3.6/site-packages/aiohttp/test_utils.py:245: in request
    method, self.make_url(path), *args, **kwargs /home/mbb/.pyenv/versions/mr/lib/python3.6/site-packages/aiohttp/helpers.py:104: in __iter__
    ret = yield from self._coro /home/mbb/.pyenv/versions/mr/lib/python3.6/site-packages/aiohttp/client.py:221: in _request
    with timer:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <aiohttp.helpers.TimerContext object at 0x7f27ec9875c0>

    def __enter__(self):
        task = current_task(loop=self._loop)

        if task is None:
>           raise RuntimeError('Timeout context manager should be used '
                               'inside a task') E           RuntimeError: Timeout context manager should be used inside a task

/home/mbb/.pyenv/versions/mr/lib/python3.6/site-packages/aiohttp/helpers.py:717: RuntimeError
=========================== 1 error in 1.74 seconds ============================ Process finished with exit code 0

我知道我可能会做

@pytest.fixture
def create_x(loop, api_client):
    x_id = loop.run_until_complete(add_x(api_client))
    return api_client, x_id

但我想知道是否存在更简单/最优雅的方法。我在 pytest、pytest-asyncio、pytest-aiohttp 的项目页面中找不到清晰简单的示例/解释。

我使用 Python 3.6.3、pytest 3.4.2、pytest-asyncio 0.8.0 和 pytest-aiohttp 0.3.0

非常感谢您的帮助

原文由 Pynchia 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

您只需要将测试标记为异步

@pytest.mark.asyncio
async def test_app(create_x, auth):
    api_client, x_id = create_x
    resp = await api_client.get(f'my_res/{x_id}', headers=auth)
    assert resp.status == web.HTTPOk.status_code

这告诉 pytest 在事件循环内运行测试而不是直接调用它。

灯具可以标记为正常

@pytest.fixture
async def create_x(api_client):
    x_id = await add_x(api_client)
    return api_client, x_id

原文由 dirn 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 2

PyTest 本身不支持协程函数，因此您需要为其安装额外的框架

• pytest-aiohttp
• pytest异步
• pytest-trio
• pytest-tornasync

如果您使用 pytest-aiohttp，您的问题将以这种方式解决

import asyncio
import pytest

from app import db

url = 'postgresql://postgres:postgres@localhost:5432'

@pytest.fixture(scope='session')
def loop():
    return asyncio.get_event_loop()

@pytest.fixture(scope='session', autouse=True)
async def prepare_db(loop):
    async with db.with_bind(f'{url}/postgres') as engine:
        await engine.status(db.text('CREATE DATABASE test_db'))

    await db.set_bind(f'{url}/test_db')
    await db.gino.create_all()

    yield
    await db.bind.close()

    async with db.with_bind(f'{url}/postgres') as engine:
        await engine.status(db.text('DROP DATABASE test_db'))

主要思想是使用同步 loop-fixture 将由异步装置使用

原文由 Максим Стукало 发布，翻译遵循 CC BY-SA 4.0 许可协议