mocking / patching external API call in python for unit-testing - python

I'm implementing unit testing for a django handler. I have been trying to mock/patch the api connection instance but keep getting the error:
super(MTurkConnection, self).__init__(aws_access_key_id,
TypeError: must be type, not MagicMock
My test code looks like this and is living in tests/test_mturk_handler.py:
class Mocked_Connection(MTurkConnection):
pass
#patch('mturk.handlers.MTurkHandler.boto.mturk.connection.MTurkConnection')
def test_can_pull_data(self, mock_api):
mock_api.return_value = Mocked_Connection()
response = self.client.post(reverse('mechanical'), self.data)
self.assertEqual(response.status_code, status.HTTP_200_OK)
The API call is beign made in this section of code and is living in handlers/MTurkHandler.py:
from boto.mturk.connection import MTurkConnection
import boto
...
if serializer.is_valid():
# instantianting connection
mturk_connection = MTurkConnection(AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, host=HOST)
I have tried several return values but I keep getting the same error. Any ideas what's the right way to do it??

Related

How to mock client object

I am working on writing unittest for my fastapi project.
One endpoint includes getting a serviceNow ticket. Here is the code i want to test:
from aiosnow.models.table.declared import IncidentModel as Incident
from fastapi import APIRouter
router = APIRouter()
#router.post("/get_ticket")
async def snow_get_ticket(req: DialogflowRequest):
"""Retrieves the status of the ticket in the parameter."""
client = create_snow_client(
SNOW_TEST_CONFIG.servicenow_url, SNOW_TEST_CONFIG.user, SNOW_TEST_CONFIG.pwd
)
params: dict = req.sessionInfo["parameters"]
ticket_num = params["ticket_num"]
try:
async with Incident(client, table_name="incident") as incident:
response = await incident.get_one(Incident.number == ticket_num)
stage_value = response.data["state"].value
desc = response.data["description"]
[...data manipulation, unimportant parts]
What i am having trouble with is trying to mock the client response, every time the actual client gets invoked and it makes the API call which i dont want.
Here is the current version of my unittest:
from fastapi.testclient import TestClient
client = TestClient(app)
#patch("aiosnow.models.table.declared.IncidentModel")
def test_get_ticket_endpoint_valid_ticket_num(self, mock_client):
mock_client.return_value = {"data" : {"state": "new",
"description": "test"}}
response = client.post(
"/snow/get_ticket", json=json.load(self.test_request)
)
assert response.status_code == 200
I think my problem is patching the wrong object, but i am not sure what else to patch.
In your test your calling client.post(...) if you don't want this to go to the Service Now API this client should be mocked.
Edit 1:
Okay so the way your test is setup now the self arg is the mocked IncidentModel object. So only this object will be a mock. Since you are creating a brand new IncidentModel object in your post method it is a real IncidentModel object, hence why its actually calling the api.
In order to mock the IncidentModel.get_one method so that it will return your mock value any time an object calls it you want to do something like this:
def test_get_ticket_endpoint_valid_ticket_num(mock_client):
mock_client.return_value = {"data" : {"state": "new",
"description": "test"}}
with patch.object(aiosnow.models.table.declared.IncidentModel, "get_one", return_value=mock_client):
response = client.post(
"/snow/get_ticket", json=json.load(self.test_request)
)
assert response.status_code == 200
The way variable assignment works in python, changing aiosnow.models.table.declared.IncidentModel will not change the IncidentModel that you've imported into your python file. You have to do the mocking where you use the object.
So instead of #patch("aiosnow.models.table.declared.IncidentModel"), you want to do #patch("your_python_file.IncidentModel")

Is it possible to run custom code before Swagger validations in a python/flask server stub?

I'm using the swagger editor (OpenApi 2) for creating flask apis in python. When you define a model in swagger and use it as a schema for the body of a request, swagger validates the body before handing the control to you in the X_controller.py files.
I want to add some code before that validation happens (for printing logs for debugging purposes). Swagger just prints to stdout errors like the following and they are not useful when you have a lot of fields (I need the key that isn't valid).
https://host/path validation error: False is not of type 'string'
10.255.0.2 - - [20/May/2020:20:20:20 +0000] "POST /path HTTP/1.1" 400 116 "-" "GuzzleHttp/7"
I know tecnically you can remove the validations in swagger and do them manually in your code but I want to keep using this feature, when it works it's awesome.
Any ideas on how to do this or any alternative to be able to log the requests are welcome.
After some time studying the matter this is what I learnt.
First let's take a look at how a python-flask server made with Swagger Editor works.
Swagger Editor generates the server stub through Swagger Codegen using the definition written in Swagger Editor. This server stub returned by codegen uses the framework Connexion on top of flask to handle all the HTTP requests and responses, including the validation against the swagger definition (swagger.yaml).
Connexion is a framework that makes it easy to develop python-flask servers because it has a lot of functionality you'd have to make yourself already built in, like parameter validation. All we need to do is replace (in this case modify) these connexion validators.
There are three validators:
ParameterValidator
RequestBodyValidator
ResponseValidator
They get mapped to flask by default but we can replace them easily in the __main__.py file as we'll see.
Our goal is to replace the default logs and default error response to some custom ones. I'm using a custom Error model and a function called error_response() for preparing error responses, and Loguru for logging the errors (not mandatory, you can keep the original one).
To make the changes needed, looking at the connexion validators code, we can see that most of it can be reused, we only need to modify:
RequestBodyValidator: __call__() and validate_schema()
ParameterValidator: __call__()
So we only need to create two new classes that extend the original ones, and copy and modify those functions.
Be careful when copying and pasting. This code is based on connexion==1.1.15. If your are on a different version you should base your classes on it.
In a new file custom_validators.py we need:
import json
import functools
from flask import Flask
from loguru import logger
from requests import Response
from jsonschema import ValidationError
from connexion.utils import all_json, is_null
from connexion.exceptions import ExtraParameterProblem
from swagger_server.models import Error
from connexion.decorators.validation import ParameterValidator, RequestBodyValidator
app = Flask(__name__)
def error_response(response: Error) -> Response:
return app.response_class(
response=json.dumps(response.to_dict(), default=str),
status=response.status,
mimetype='application/json')
class CustomParameterValidator(ParameterValidator):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def __call__(self, function):
"""
:type function: types.FunctionType
:rtype: types.FunctionType
"""
#functools.wraps(function)
def wrapper(request):
if self.strict_validation:
query_errors = self.validate_query_parameter_list(request)
formdata_errors = self.validate_formdata_parameter_list(request)
if formdata_errors or query_errors:
raise ExtraParameterProblem(formdata_errors, query_errors)
for param in self.parameters.get('query', []):
error = self.validate_query_parameter(param, request)
if error:
response = error_response(Error(status=400, description=f'Error: {error}'))
return self.api.get_response(response)
for param in self.parameters.get('path', []):
error = self.validate_path_parameter(param, request)
if error:
response = error_response(Error(status=400, description=f'Error: {error}'))
return self.api.get_response(response)
for param in self.parameters.get('header', []):
error = self.validate_header_parameter(param, request)
if error:
response = error_response(Error(status=400, description=f'Error: {error}'))
return self.api.get_response(response)
for param in self.parameters.get('formData', []):
error = self.validate_formdata_parameter(param, request)
if error:
response = error_response(Error(status=400, description=f'Error: {error}'))
return self.api.get_response(response)
return function(request)
return wrapper
class CustomRequestBodyValidator(RequestBodyValidator):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def __call__(self, function):
"""
:type function: types.FunctionType
:rtype: types.FunctionType
"""
#functools.wraps(function)
def wrapper(request):
if all_json(self.consumes):
data = request.json
if data is None and len(request.body) > 0 and not self.is_null_value_valid:
# the body has contents that were not parsed as JSON
return error_response(Error(
status=415,
description="Invalid Content-type ({content_type}), JSON data was expected".format(content_type=request.headers.get("Content-Type", ""))
))
error = self.validate_schema(data, request.url)
if error and not self.has_default:
return error
response = function(request)
return response
return wrapper
def validate_schema(self, data, url):
if self.is_null_value_valid and is_null(data):
return None
try:
self.validator.validate(data)
except ValidationError as exception:
description = f'Validation error. Attribute "{exception.validator_value}" return this error: "{exception.message}"'
logger.error(description)
return error_response(Error(
status=400,
description=description
))
return None
Once we have our validators, we have to map them to the flask app (__main__.py) using validator_map:
validator_map = {
'parameter': CustomParameterValidator,
'body': CustomRequestBodyValidator,
'response': ResponseValidator,
}
app = connexion.App(__name__, specification_dir='./swagger/', validator_map=validator_map)
app.app.json_encoder = encoder.JSONEncoder
app.add_api(Path('swagger.yaml'), arguments={'title': 'MyApp'})
If you also need to replace the validator I didn't use in this example, just create a custom child class of ResponseValidator and replace it on the validator_map dictionary in __main__.py.
Connexion docs:
https://connexion.readthedocs.io/en/latest/request.html
Forgive me for repeating an answer first posted at https://stackoverflow.com/a/73051652/1630244
Have you tried the Connexion before_request feature? Here's an example that logs the headers and content before Connexion validates the body:
import connexion
import logging
from flask import request
logger = logging.getLogger(__name__)
conn_app = connexion.FlaskApp(__name__)
#conn_app.app.before_request
def before_request():
for h in request.headers:
logger.debug('header %s', h)
logger.debug('data %s', request.get_data())

flask/python creating multiple TestCase classes returns 404

While running python's unittest in my Flask application, I am returned a 404 status code when using multiple TestCase classes.
I've tried flask_testing and have gotten similar issues. I opted for unittest because of its greater popularity and availability to find documentation online.
test_global.py
from server import create_app
class Global(unittest.TestCase):
def setUp(self):
self.app = create_app(testing=True)
self.client = self.app.test_client()
self.client.testing = True
# tests different cookie redirect
def test_different_cookie_redirect(self):
self.client.set_cookie('127.0.0.1', 'lang', 'en')
response = self.client.get('/fr')
# this passes
self.assertEqual(response.status_code, 302)
The above works as intended. If the cookie is different, the page should redirect. The problem happens when I want to add another class.
class Index(unittest.TestCase):
def setUp(self):
self.app = create_app(testing=True)
self.client = self.app.test_client()
self.client.testing = True
# tests same cookie redirect
def test_same_cookie_redirect(self):
self.client.set_cookie('127.0.0.1', 'lang', 'fr')
response = self.client.get('/fr')
# this returns a 404 and fails the test
self.assertEqual(response.status_code, 200)
This is the error
Traceback (most recent call last):
File "/test_global.py", line 55, in test_same_cookie_redirect
self.assertEqual(response.status_code, 200)
AssertionError: 404 != 200
If I remove the Global class, the Index test then works and returns a status_code of 200. Why can't both work at the same time?
The reason I opted to have multiple classes is to be able to split my code in different files and run python -m unittest discover to handle them all.

Python unittest mock an API key

I'm writing unit tests for the Client class of client.py, which queries an API. Each test instantiates the client with c = client.Client("apikey"). Running one test at a time works fine, but running them all (e.g. with py.test) I get a 401: "Exception: Response 401: Unauthorized Access. Requests must contain a valid api-key."
I have a valid API key but this should not be included in the unit tests. I would appreciate an explanation of why "apikey" works for only one query. More specifically, how can I mock out the calls to the API? Below is an example unit test:
def testGetContextReturnFields(self):
c = client.Client("apikey")
contexts = c.getContext("foo")
assert(isinstance(contexts[0]["context_label"], str))
assert(contexts[0]["context_id"] == 0)
Separate out the tests for API calls and for the Client.getContext() method. For explicitly testing the API calls, patch a request object...
import client
import httpretty
import requests
from mock import Mock, patch
...
def testGetQueryToAPI(self):
"""
Tests the client can send a 'GET' query to the API, asserting we receive
an HTTP status code reflecting successful operation.
"""
# Arrange: patch the request in client.Client._queryAPI().
with patch.object(requests, 'get') as mock_get:
mock_get.return_value = mock_response = Mock()
mock_response.status_code = 200
# Act:
c = client.Client()
response = c._queryAPI("path", 'GET', {}, None, {})
# Assert:
self.assertEqual(response.status_code, 200)
# Repeat the same test for 'POST' queries.
And for testing getContext(), mock out the HTTP with httpretty...
#httpretty.activate
def testGetContextReturnFields(self):
"""
Tests client.getContext() for a sample term.
Asserts the returned object contains the corrcet fields and have contents as
expected.
"""
# Arrange: mock JSON response from API, mock out the API endpoint we expect
# to be called.
mockResponseString = getMockApiData("context_foo.json")
httpretty.register_uri(httpretty.GET,
"http://this.is.the.url/query",
body=mockResponseString,
content_type="application/json")
# Act: create the client object we'll be testing.
c = client.Client()
contexts = c.getContext("foo")
# Assert: check the result object.
self.assertTrue(isinstance(contexts, list),
"Returned object is not of type list as expected.")
self.assertTrue(("context_label" and "context_id") in contexts[0],
"Data structure returned by getContext() does not contain"
" the required fields.")
self.assertTrue(isinstance(contexts[0]["context_label"], str),
"The \'context_label\' field is not of type string.")
self.assertEqual(contexts[0]["context_id"], 0,
"The top context does not have ID of zero.")

Python mock, django and requests

So, I've just started using mock with a Django project. I'm trying to mock out part of a view which makes a request to a remote API to confirm a subscription request was genuine (a form of verification as per the spec I'm working to).
What I have resembles:
class SubscriptionView(View):
def post(self, request, **kwargs):
remote_url = request.POST.get('remote_url')
if remote_url:
response = requests.get(remote_url, params={'verify': 'hello'})
if response.status_code != 200:
return HttpResponse('Verification of request failed')
What I now want to do is to use mock to mock out the requests.get call to change the response, but I can't work out how to do this for the patch decorator. I'd thought you do something like:
#patch(requests.get)
def test_response_verify(self):
# make a call to the view using self.app.post (WebTest),
# requests.get makes a suitable fake response from the mock object
How do I achieve this?
You're almost there. You're just calling it slightly incorrectly.
from mock import call, patch
#patch('my_app.views.requests')
def test_response_verify(self, mock_requests):
# We setup the mock, this may look like magic but it works, return_value is
# a special attribute on a mock, it is what is returned when it is called
# So this is saying we want the return value of requests.get to have an
# status code attribute of 200
mock_requests.get.return_value.status_code = 200
# Here we make the call to the view
response = SubscriptionView().post(request, {'remote_url': 'some_url'})
self.assertEqual(
mock_requests.get.call_args_list,
[call('some_url', params={'verify': 'hello'})]
)
You can also test that the response is the correct type and has the right content.
It's all in the documentation:
patch(target, new=DEFAULT, spec=None, create=False, spec_set=None, autospec=None, new_callable=None, **kwargs)
target should be a string in the form ‘package.module.ClassName’.
from mock import patch
# or #patch('requests.get')
#patch.object(requests, 'get')
def test_response_verify(self):
# make a call to the view using self.app.post (WebTest),
# requests.get makes a suitable fake response from the mock object

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