aiohttp + pytest + unittest mock

test_.py

import aiohttp
from asyncio import Future
from unittest.mock import MagicMock, Mock, patch

def test_taxi_route_info(aiohttp_client, loop):
    async def taxi_route_info():
        connector = aiohttp.TCPConnector(ssl=False)
        session = aiohttp.ClientSession(connector=connector, loop=loop)

        taxi_route_info = TaxiRouteInfo(session=session)
        taxi_info = await session.get('https://...')

        await session.close()
        assert True == True

    with patch('aiohttp.client.ClientSession.get') as mock_get:
        response = aiohttp.ClientResponse(method='GET', url='/', ...)

        mock_get.return_value = Future()
        mock_get.return_value.set_result(response)

        loop.run_until_complete(taxi_route_info())