I am trying to use Pythons mock package to mock Pythons requests
module. What are the basic calls to get me working in below scenario?
In my views.py, I have a function that makes variety of requests.get() calls with different response each time
def myview(request):
res1 = requests.get('aurl')
res2 = request.get('burl')
res3 = request.get('curl')
In my test class I want to do something like this but cannot figure out exact method calls
Step 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'
Step 2:
Call my view
Step 3:
verify response contains 'a response', 'b response' , 'c response'
How can I complete Step 1 (mocking the requests module)?
Here is a solution with requests Response class. It is cleaner IMHO.
from unittest.mock import patch
from requests.models import Response
def mocked_request_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 = call_your_view()
assert ...
This is how you can do it (you can run this file as-is):
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()
Important Note: If your MyGreatClass
class lives in a different package, say my.great.package
, you have to mock my.great.package.requests.get
instead of just 'request.get'. In that case your test case would look like this:
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()
Enjoy!
I used requests-mock for writing tests for separate module:
# module.py
import requests
class A():
def get_response(self, url):
response = requests.get(url)
return response.text
And the tests:
# 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()
this is how you mock requests.post, change it to your http method
@patch.object(requests, 'post')
def your_test_method(self, mockpost):
mockresponse = Mock()
mockpost.return_value = mockresponse
mockresponse.text = 'mock return'
#call your target method now
Just a helpful hint to those that are still struggling, converting from urllib or urllib2/urllib3 to requests AND trying to mock a response- I was getting a slightly confusing error when implementing my mock:
with requests.get(path, auth=HTTPBasicAuth('user', 'pass'), verify=False) as url:
AttributeError: __enter__
Well, of course, if I knew anything about how with
works (I didn't), I'd know it was a vestigial, unnecessary context (from PEP 343). Unnecessary when using the requests library because it does basically the same thing for you under the hood. Just remove the with
and use bare requests.get(...)
and Bob's your uncle.
If you want to mock a fake response, another way to do it is to simply instantiate an instance of the base HttpResponse class, like so:
from django.http.response import HttpResponseBase
self.fake_response = HttpResponseBase()
I will add this information since I had a hard time figuring how to mock an async api call.
Here is what I did to mock an async call.
Here is the function I wanted to test
async def get_user_info(headers, payload):
return await httpx.AsyncClient().post(URI, json=payload, headers=headers)
You still need the MockResponse class
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
You add the MockResponseAsync class
class MockResponseAsync:
def __init__(self, json_data, status_code):
self.response = MockResponse(json_data, status_code)
async def getResponse(self):
return self.response
Here is the test. The important thing here is I create the response before since init function can't be async and the call to getResponse is async so it all checked out.
@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)
If you have a better way of doing that tell me but I think it's pretty clean like that.
I started out with Johannes Farhenkrug's answer here and it worked great for me. I needed to mock the requests library because my goal is to isolate my application and not test any 3rd party resources.
Then I read up some more about python's Mock library and I realized that I can replace the MockResponse class, which you might call a 'Test Double' or a 'Fake', with a python Mock class.
The advantage of doing so is access to things like assert_called_with
, call_args
and so on. No extra libraries are needed. Additional benefits such as 'readability' or 'its more pythonic' are subjective, so they may or may not play a role for you.
Here is my version, updated with using python's Mock instead of a 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.it links:
https://repl.it/@abkonsta/Using-unittestMock-for-requestspost#main.py
https://repl.it/@abkonsta/Using-test-double-for-requestspost#main.py
Try using the responses library. Here is an example from their documentation:
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"}'
It provides quite a nice convenience over setting up all the mocking yourself.
There's also HTTPretty:
It's not specific to requests
library, more powerful in some ways though I found it doesn't lend itself so well to inspecting the requests that it intercepted, which responses
does quite easily
There's also httmock.
One possible way to work around requests is using the library betamax, it records all requests and after that if you make a request in the same url with the same parameters the betamax will use the recorded request, I have been using it to test web crawler and it save me a lot time.
import os
import requests
from betamax import Betamax
from betamax_serializers import pretty_json
WORKERS_DIR = os.path.dirname(os.path.abspath(__file__))
CASSETTES_DIR = os.path.join(WORKERS_DIR, u'resources', u'cassettes')
MATCH_REQUESTS_ON = [u'method', u'uri', u'path', u'query']
Betamax.register_serializer(pretty_json.PrettyJSONSerializer)
with Betamax.configure() as config:
config.cassette_library_dir = CASSETTES_DIR
config.default_cassette_options[u'serialize_with'] = u'prettyjson'
config.default_cassette_options[u'match_requests_on'] = MATCH_REQUESTS_ON
config.default_cassette_options[u'preserve_exact_body_bytes'] = True
class WorkerCertidaoTRT2:
session = requests.session()
def make_request(self, input_json):
with Betamax(self.session) as vcr:
vcr.use_cassette(u'google')
response = session.get('http://www.google.com')
Source: Stackoverflow.com