(2023.04.02 Sun@HRB)
在Python的unittest中测试async对象，被mock的对象须要保持async对象的界说和调用方式。
unittest包中包罗一个IsolatedAsyncioTestCase，该test case始于Python3.8版本。该test case和TestCase类似，差别在于前者用于对test case写入协程，并可调用其他协程和使用await关键字。在测试类中可混淆使用同步和异步测试。
下面案例
import asyncioimport unittestasync def sleep(): await asyncio.sleep(0.5) return Trueclass testClass(unittest.IsolatedAsyncioTestCase): async def test_async(self): res = await sleep() self.assertTrue(res) 用pytest test_asyncio.py运行
(base) C:\>pytest test_asyncio.py================================== test session starts ==================================platform win32 -- Python 3.8.5, pytest-6.1.1, py-1.9.0, pluggy-0.13.1rootdir: C:\collected 1 itemtest_asyncio.py . [100%]异步test case支持TestCase中的setUp和tearDown方法，其名为asyncSetUp和asyncTearDown，继承协程。不外IsolatedAsyncioTestCase也支持setUpClass和tearDownClass类。
与MagicMock类似的AsyncMock类
(2023.04.03 Mon@HRB)
unittest.mock中包罗一个异步版本的MagicMock，即AsyncMock，用于创建异步的mock。和MagicMock相似，AsyncMock也有side_effect和return_value两个属性，而且属性运动相似，await AsyncMock将返回return_value或side_effect，但留意调用时须要采取异步方式。如下面的案例，在调用时，my_mock()调用返回的是一个协程，必须使用await关键字才华返回结果。
import unittestfrom unittest.mock import AsyncMockclass testCase(unittest.IsolatedAsyncioTestCase): async def test_mocking_demo(self): amock = AsyncMock() amock.return_value = 298 r = amock() print(type(r)) await_result = await r print(await_result) self.assertEqual(298, await amock())Mock天生器函数和context manager
mock天生器函数和contxt manager仅须要修改该函数中的特定magic mthod，分别是__aiter和__aenter__。示比方下
import unittestfrom unittest.mock import AsyncMock, Mockclass TestMockingDemo(unittest.IsolatedAsyncioTestCase): async def test_mock_generator(self): expected_values = ["foo", "bar", "baz"] my_mock_generator = AsyncMock() my_mock_generator.__aiter__.return_value = expected_values actual_values = [] async for value in my_mock_generator: actual_values.append(value) self.assertListEqual(expected_values, actual_values) async def test_mock_context_manager(self): mock_cm = AsyncMock() # Note that by default an AsyncMock returns more AsyncMocks - we have to replace it with a Mock if we want a # synchronous function mock_cm.get_state = Mock(return_value="Not entered") # Get a context object as a result of entering the context manager. Alternatively, __aenter__ could return # mock_cm, to emulate the behaviour of returning self upon entering the context manager mock_ctx = AsyncMock() mock_cm.__aenter__.return_value = mock_ctx mock_ctx.get_state = Mock(return_value="Entered") print(mock_cm.get_state()) self.assertEqual("Not entered", mock_cm.get_state()) async with mock_cm as entered_ctx: print(entered_ctx.get_state()) self.assertEqual("Entered", entered_ctx.get_state()) async def test_mock_has_awaits(self): my_mock = AsyncMock() my_mock.assert_not_awaited() await my_mock(27) my_mock.assert_awaited_once_with(27)Reference
1 bbc点github点io/cloudfit减号public减号docs/asyncio/testing.html |
