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)?
下面是一个带有请求响应类的解决方案。恕我直言，它更干净。
import json
from unittest.mock import patch
from requests.models import Response
def mocked_requests_get(*args, **kwargs):
response_content = None
request_url = kwargs.get('url', None)
if request_url == 'aurl':
response_content = json.dumps('a response')
elif request_url == 'burl':
response_content = json.dumps('b response')
elif request_url == 'curl':
response_content = json.dumps('c response')
response = Response()
response.status_code = 200
response._content = str.encode(response_content)
return response
@mock.patch('requests.get', side_effect=mocked_requests_get)
def test_fetch(self, mock_get):
response = requests.get(url='aurl')
assert ...
对于那些不想为pytest安装额外库的人，这里有一个例子。我将在这里复制一些扩展，基于上面的例子:
import datetime
import requests
class MockResponse:
def __init__(self, json_data, status_code):
self.json_data = json_data
self.status_code = status_code
self.elapsed = datetime.timedelta(seconds=1)
# mock json() method always returns a specific testing dictionary
def json(self):
return self.json_data
def test_get_json(monkeypatch):
# Any arguments may be passed and mock_get() will always return our
# mocked object, which only has the .json() method.
def mock_get(*args, **kwargs):
return MockResponse({'mock_key': 'mock_value'}, 418)
# apply the monkeypatch for requests.get to mock_get
monkeypatch.setattr(requests, 'get', mock_get)
# app.get_json, which contains requests.get, uses the monkeypatch
response = requests.get('https://fakeurl')
response_json = response.json()
assert response_json['mock_key'] == 'mock_value'
assert response.status_code == 418
assert response.elapsed.total_seconds() == 1
============================= test session starts ==============================
collecting ... collected 1 item
test_so.py::test_get_json PASSED [100%]
============================== 1 passed in 0.07s ===============================
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!
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()
尝试使用响应库。以下是他们文档中的一个例子:
import responses
import requests
@responses.activate
def test_simple():
responses.add(responses.GET, 'http://twitter.com/api/1/foobar',
json={'error': 'not found'}, status=404)
resp = requests.get('http://twitter.com/api/1/foobar')
assert resp.json() == {"error": "not found"}
assert len(responses.calls) == 1
assert responses.calls[0].request.url == 'http://twitter.com/api/1/foobar'
assert responses.calls[0].response.text == '{"error": "not found"}'
相比于自己设置所有的mock，它提供了相当好的便利。
还有HTTPretty:
它不是特定于请求库，在某些方面更强大，尽管我发现它不太适合检查它拦截的请求，而响应则很容易
还有httmock。
最近，一个比古老的请求更受欢迎的新库是httpx，它增加了对异步的一等支持。httpx的模拟库是:https://github.com/lundberg/respx
