我试图使用python模拟包来模拟python请求模块。让我在下面的场景中工作的基本调用是什么?

在views.py中,我有一个函数,它每次都以不同的响应进行各种request .get()调用

def myview(request):
  res1 = requests.get('aurl')
  res2 = request.get('burl')
  res3 = request.get('curl')

在我的测试类中,我想做类似的事情,但不能确定确切的方法调用

步骤1:

# Mock the requests module
# when mockedRequests.get('aurl') is called then return 'a response'
# when mockedRequests.get('burl') is called then return 'b response'
# when mockedRequests.get('curl') is called then return 'c response'

步骤2:

调用我的视图

步骤3:

验证响应包含'a response', 'b response', 'c response'

我如何完成第1步(模拟请求模块)?


当前回答

为了避免安装其他依赖项,您应该创建一个假响应。这个FakeResponse可以是Response的子类(我认为这是一个很好的方法,因为它更现实),或者只是一个具有您需要的属性的简单类。

简单的假类

class FakeResponse:
        status_code = None

        def __init__(self, *args, **kwargs):
            self.status_code = 500
            self.text = ""

回应之子

class FakeResponse(Response):
        encoding = False
        _content = None

        def __init__(*args, **kwargs):
            super(FakeResponse).__thisclass__.status_code = 500
            # Requests requires to be not be None, if not throws an exception
            # For reference: https://github.com/psf/requests/issues/3698#issuecomment-261115119
            super(FakeResponse).__thisclass__.raw = io.BytesIO()

其他回答

你可以这样做(你可以按原样运行这个文件):

import requests
import unittest
from unittest import mock

# This is the class we want to test
class MyGreatClass:
    def fetch_json(self, url):
        response = requests.get(url)
        return response.json()

# This method will be used by the mock to replace requests.get
def mocked_requests_get(*args, **kwargs):
    class MockResponse:
        def __init__(self, json_data, status_code):
            self.json_data = json_data
            self.status_code = status_code

        def json(self):
            return self.json_data

    if args[0] == 'http://someurl.com/test.json':
        return MockResponse({"key1": "value1"}, 200)
    elif args[0] == 'http://someotherurl.com/anothertest.json':
        return MockResponse({"key2": "value2"}, 200)

    return MockResponse(None, 404)

# Our test case class
class MyGreatClassTestCase(unittest.TestCase):

    # We patch 'requests.get' with our own method. The mock object is passed in to our test case method.
    @mock.patch('requests.get', side_effect=mocked_requests_get)
    def test_fetch(self, mock_get):
        # Assert requests.get calls
        mgc = MyGreatClass()
        json_data = mgc.fetch_json('http://someurl.com/test.json')
        self.assertEqual(json_data, {"key1": "value1"})
        json_data = mgc.fetch_json('http://someotherurl.com/anothertest.json')
        self.assertEqual(json_data, {"key2": "value2"})
        json_data = mgc.fetch_json('http://nonexistenturl.com/cantfindme.json')
        self.assertIsNone(json_data)

        # We can even assert that our mocked method was called with the right parameters
        self.assertIn(mock.call('http://someurl.com/test.json'), mock_get.call_args_list)
        self.assertIn(mock.call('http://someotherurl.com/anothertest.json'), mock_get.call_args_list)

        self.assertEqual(len(mock_get.call_args_list), 3)

if __name__ == '__main__':
    unittest.main()

重要提示:如果你的MyGreatClass类位于不同的包中,请输入my.great。你必须模仿my。great。Package。requests。get而不是request。get。在这种情况下,你的测试用例看起来像这样:

import unittest
from unittest import mock
from my.great.package import MyGreatClass

# This method will be used by the mock to replace requests.get
def mocked_requests_get(*args, **kwargs):
    # Same as above


class MyGreatClassTestCase(unittest.TestCase):

    # Now we must patch 'my.great.package.requests.get'
    @mock.patch('my.great.package.requests.get', side_effect=mocked_requests_get)
    def test_fetch(self, mock_get):
        # Same as above

if __name__ == '__main__':
    unittest.main()

享受吧!

我使用requests-mock为单独的模块编写测试:

# module.py
import requests

class A():

    def get_response(self, url):
        response = requests.get(url)
        return response.text

测试:

# tests.py
import requests_mock
import unittest

from module import A


class TestAPI(unittest.TestCase):

    @requests_mock.mock()
    def test_get_response(self, m):
        a = A()
        m.get('http://aurl.com', text='a response')
        self.assertEqual(a.get_response('http://aurl.com'), 'a response')
        m.get('http://burl.com', text='b response')
        self.assertEqual(a.get_response('http://burl.com'), 'b response')
        m.get('http://curl.com', text='c response')
        self.assertEqual(a.get_response('http://curl.com'), 'c response')

if __name__ == '__main__':
    unittest.main()

我将添加这些信息,因为我很难弄清楚如何模拟异步api调用。

以下是我模拟异步调用所做的工作。

这是我想测试的函数

async def get_user_info(headers, payload):
    return await httpx.AsyncClient().post(URI, json=payload, headers=headers)

您仍然需要MockResponse类

class MockResponse:
    def __init__(self, json_data, status_code):
        self.json_data = json_data
        self.status_code = status_code

    def json(self):
        return self.json_data

添加MockResponseAsync类

class MockResponseAsync:
    def __init__(self, json_data, status_code):
        self.response = MockResponse(json_data, status_code)

    async def getResponse(self):
        return self.response

下面是测试。这里重要的是,我之前创建了响应,因为init函数不能是异步的,对getResponse的调用是异步的,所以它都签出了。

@pytest.mark.asyncio
@patch('httpx.AsyncClient')
async def test_get_user_info_valid(self, mock_post):
    """test_get_user_info_valid"""
    # Given
    token_bd = "abc"
    username = "bob"
    payload = {
        'USERNAME': username,
        'DBNAME': 'TEST'
    }
    headers = {
        'Authorization': 'Bearer ' + token_bd,
        'Content-Type': 'application/json'
    }
    async_response = MockResponseAsync("", 200)
    mock_post.return_value.post.return_value = async_response.getResponse()

    # When
    await api_bd.get_user_info(headers, payload)

    # Then
    mock_post.return_value.post.assert_called_once_with(
        URI, json=payload, headers=headers)

如果你有更好的方法告诉我,不过我觉得这样很干净。

我从Johannes Farhenkrug的答案开始,它对我很有效。我需要模拟请求库,因为我的目标是隔离我的应用程序,不测试任何第三方资源。

然后我读了更多关于python的Mock库,我意识到我可以用python Mock类替换MockResponse类,你可能称之为“Test Double”或“Fake”。

这样做的好处是可以访问assert_called_with, call_args等。不需要额外的库。额外的好处,如“可读性”或“更python化”是主观的,所以它们可能对你有影响,也可能没有。

这是我的版本,更新使用python的Mock而不是test double:

import json
import requests
from unittest import mock

# defube stubs
AUTH_TOKEN = '{"prop": "value"}'
LIST_OF_WIDGETS = '{"widgets": ["widget1", "widget2"]}'
PURCHASED_WIDGETS = '{"widgets": ["purchased_widget"]}'


# exception class when an unknown URL is mocked
class MockNotSupported(Exception):
  pass


# factory method that cranks out the Mocks
def mock_requests_factory(response_stub: str, status_code: int = 200):
    return mock.Mock(**{
        'json.return_value': json.loads(response_stub),
        'text.return_value': response_stub,
        'status_code': status_code,
        'ok': status_code == 200
    })


# side effect mock function
def mock_requests_post(*args, **kwargs):
    if args[0].endswith('/api/v1/get_auth_token'):
        return mock_requests_factory(AUTH_TOKEN)
    elif args[0].endswith('/api/v1/get_widgets'):
        return mock_requests_factory(LIST_OF_WIDGETS)
    elif args[0].endswith('/api/v1/purchased_widgets'):
        return mock_requests_factory(PURCHASED_WIDGETS)
    
    raise MockNotSupported


# patch requests.post and run tests
with mock.patch('requests.post') as requests_post_mock:
  requests_post_mock.side_effect = mock_requests_post
  response = requests.post('https://myserver/api/v1/get_widgets')
  assert response.ok is True
  assert response.status_code == 200
  assert 'widgets' in response.json()
  
  # now I can also do this
  requests_post_mock.assert_called_with('https://myserver/api/v1/get_widgets')

Repl。它的链接:

https://repl.it/@abkonsta/Using-unittestMock-for-requestspost#main.py

https://repl.it/@abkonsta/Using-test-double-for-requestspost#main.py

您可以使用request -mock代替吗?

假设你的myview函数接受一个请求。Session对象,用它发出请求,并对输出做一些事情:

# mypackage.py
def myview(session):
    res1 = session.get("http://aurl")
    res2 = session.get("http://burl")
    res3 = session.get("http://curl")
    return f"{res1.text}, {res2.text}, {res3.text}"
# test_myview.py
from mypackage import myview
import requests

def test_myview(requests_mock):
    # set up requests
    a_req = requests_mock.get("http://aurl", text="a response")
    b_req = requests_mock.get("http://burl", text="b response")
    c_req = requests_mock.get("http://curl", text="c response")

    # test myview behaviour
    session = requests.Session()
    assert myview(session) == "a response, b response, c response"

    # check that requests weren't called repeatedly
    assert a_req.called_once
    assert b_req.called_once
    assert c_req.called_once
    assert requests_mock.call_count == 3

你也可以在Pytest之外的框架中使用requests_mock——文档非常棒。