I am having a problem understanding how mock works and how to write unittests with mock objects. I wanted to mock an external api call every time when my model calls save() method.
My code:
models.py
from . import utils
class Book(Titleable, Isactiveable, Timestampable, IsVoidable, models.Model):
title
orig_author
orig_title
isbn
def save(self, *args, **kwargs):
if self.isbn:
google_data = utils.get_original_title_and_name(self.isbn)
if google_data:
self.original_author = google_data['author']
self.original_title = google_data['title']
super().save(*args, **kwargs)
utils.py
def get_original_title_and_name(isbn, **kawargs):
isbn_search_string = 'isbn:{}'.format(isbn)
payload = {
'key': GOOGLE_API_KEY,
'q': isbn_search_string,
'printType': 'books',
}
r = requests.get(GOOGLE_API_URL, params=payload)
response = r.json()
if 'items' in response.keys():
title = response['items'][THE_FIRST_INDEX]['volumeInfo']['title']
author = response['items'][THE_FIRST_INDEX]['volumeInfo']['authors'][THE_FIRST_INDEX]
return {
'title': title,
'author': author
}
else:
return None
I began read docs and write test:
test.py:
from unittest import mock
from django.test import TestCase
from rest_framework import status
from .constants import THE_FIRST_INDEX, GOOGLE_API_URL, GOOGLE_API_KEY
class BookModelTestCase(TestCase):
#mock.patch('requests.get')
def test_get_original_title_and_name_from_google_api(self, mock_get):
# Define new Mock object
mock_response = mock.Mock()
# Define response data from Google API
expected_dict = {
'kind': 'books#volumes',
'totalItems': 1,
'items': [
{
'kind': 'books#volume',
'id': 'IHxXBAAAQBAJ',
'etag': 'B3N9X8vAMWg',
'selfLink': 'https://www.googleapis.com/books/v1/volumes/IHxXBAAAQBAJ',
'volumeInfo': {
'title': "Alice's Adventures in Wonderland",
'authors': [
'Lewis Carroll'
]
}
}
]
}
# Define response data for my Mock object
mock_response.json.return_value = expected_dict
mock_response.status_code = 200
# Define response for the fake API
mock_get.return_value = mock_response
The first of all, I can't write target for the #mock.patch correct. If a define target as utuls.get_original_title_and_name.requests.get, I get ModuleNotFoundError. Also I can't understand how to make fake-call to external API and verify recieved data (whether necessarly its, if I've already define mock_response.json.return_value = expected_dict?) and verify that my save() method work well?
How do I write test for this cases? Could anyone explain me this case?
You should mock the direct collaborators of the code under test. For Book that would be utils. For utils that would be requests.
So for the BookModelTestCase:
class BookModelTestCase(TestCase):
#mock.patch('app.models.utils')
def test_save_book_calls_google_api(self, mock_utils):
mock_utils.get_original_title_and_name.return_value = {
'title': 'Google title',
'author': 'Google author'
}
book = Book(
title='Some title',
isbn='12345'
)
book.save()
self.assertEqual(book.title, 'Google title')
self.assertEqual(book.author, 'Google author')
mock_utils.get_original_title_and_name.assert_called_once_with('12345')
And then you can create a separate test case to test get_original_title_and_name:
class GetOriginalTitleAndNameTestCase(TestCase):
#mock.patch('app.utils.requests.get')
def test_get_original_title_and_name_from_google_api(self, mock_get):
mock_response = mock.Mock()
# Define response data from Google API
expected_dict = {
'kind': 'books#volumes',
'totalItems': 1,
'items': [
{
'kind': 'books#volume',
'id': 'IHxXBAAAQBAJ',
'etag': 'B3N9X8vAMWg',
'selfLink': 'https://www.googleapis.com/books/v1/volumes/IHxXBAAAQBAJ',
'volumeInfo': {
'title': "Alice's Adventures in Wonderland",
'authors': [
'Lewis Carroll'
]
}
}
]
}
# Define response data for my Mock object
mock_response.json.return_value = expected_dict
mock_response.status_code = 200
# Define response for the fake API
mock_get.return_value = mock_response
# Call the function
result = get_original_title_and_name(12345)
self.assertEqual(result, {
'title': "Alice's Adventures in Wonderland",
'author': 'Lewis Carroll'
})
mock_get.assert_called_once_with(GOOGLE_API_URL, params={
'key': GOOGLE_API_KEY,
'q': 'isbn:12345',
'printType': 'books',
})
Related
I am consuming the Yelp API and using this detail view to display details of individual restaurants such as the name, rating and price of a restaurant. The detail dictionary is solid for the most part and lets me collect variables to use as context in template. However some restaurants do not provide their 'price' to the API, therefore when accessing this view I get a KeyError because there is no price in some cases. How can I create this dictionary with a None value for price to avoid this error? Or is exception handling with try & except the best solution?
def detail(request, api_id):
API_KEY = 'unique_key'
url = 'https://api.yelp.com/v3/businesses/'+ api_id
headers = {'Authorization': 'Bearer {}'.format(API_KEY)}
req = requests.get(url, headers=headers)
parsed = json.loads(req.text)
detail = {
'id': parsed['id'],
'name': parsed['name'],
'rating':parsed['rating'],
'price': parsed['price'],
}
context = {'detail': detail}
return render(request, 'API/detail.html', context)
You can use <dict>.get('key', default_value):
detail = {
'id': parsed['id'],
'name': parsed['name'],
'rating':parsed['rating'],
'price': parsed.get('price', None), # <-- here
}
W3School has a nice example on how to use .get() method.
you can try:
detail = {
'id': parsed['id'],
'name': parsed['name'],
'rating':parsed['rating'],
'price': parsed['price'] if parsed['price'] else None,
}
I have a function that verifies if a given input string is a proper GCP zone:
def validate_zone(compute, project_id, zone):
try:
zone_response = compute.zones().get(project=project_id, zone=zone).execute()
print(zone_response)
print(zone_response.return_value)
if ['status'] in zone_response:
zone_details = {
'status': zone_response['status'],
'region': zone_response['region'],
'name': zone_response['name']
}
return zone_details
else:
return "Zone {} not found for project {}".format(zone, project_id)
except HttpError as error:
print("Error calling zone {}: \n {}".format(zone, error))
I am trying to write a test to verify that but I can't mock the output of the compute method correctly.
#patch('googleapiclient.discovery')
def test_validate_zone(self, mock_response):
compute = mock_response.build(serviceName='compute', version='v1')
compute.zones().get(project_id=self.project_id, zone=self.zone).execute().return_value = {
'status': 'status',
'region': 'region',
'name': 'name'
}
zone_response = inventory.validate_zone(compute, self.project_id, self.zone)
print(zone_response)
This results in the zone_response output being a MagicMock object with its return_value being correct as developed in the test.
zone_response = MagicMock name='discovery.build().zones().get().execute()' id='139870134525456'
zone_response.return_value = {'status': 'status', 'region': 'region', 'name': 'name'}
Any ideas on what I'm doing wrong? I've been trying to write tests for this for quite a while so maybe my approach is just off.
Turns out the issue was the () on the execute method in the test. So the correct test should be:
#patch('inventory.discovery.build', serviceName='compute', version='v1')
def test_validate_zone(self, compute):
print(compute)
compute.zones().get(project_id=self.project_id, zone=self.zone).execute.return_value = {
'status': 'status',
'region': 'region',
'name': 'name'
}
zone_response = inventory.validate_zone(compute, self.project_id, self.zone)
print(zone_response)
Source can be found at: https://realpython.com/python-mock-library/#managing-a-mocks-return-value
What is the proper way to handle response classes in Flask-RESTplus?
I am experimenting with a simple GET request seen below:
i_throughput = api.model('Throughput', {
'date': fields.String,
'value': fields.String
})
i_server = api.model('Server', {
'sessionId': fields.String,
'throughput': fields.Nested(i_throughput)
})
#api.route('/servers')
class Server(Resource):
#api.marshal_with(i_server)
def get(self):
servers = mongo.db.servers.find()
data = []
for x in servers:
data.append(x)
return data
I want to return my data in as part of a response object that looks like this:
{
status: // some boolean value
message: // some custom response message
error: // if there is an error store it here
trace: // if there is some stack trace dump throw it in here
data: // what was retrieved from DB
}
I am new to Python in general and new to Flask/Flask-RESTplus. There is a lot of tutorials out there and information. One of my biggest problems is that I'm not sure what to exactly search for to get the information I need. Also how does this work with marshalling? If anyone can post good documentation or examples of excellent API's, it would be greatly appreciated.
https://blog.miguelgrinberg.com/post/customizing-the-flask-response-class
from flask import Flask, Response, jsonify
app = Flask(__name__)
class CustomResponse(Response):
#classmethod
def force_type(cls, rv, environ=None):
if isinstance(rv, dict):
rv = jsonify(rv)
return super(MyResponse, cls).force_type(rv, environ)
app.response_class = CustomResponse
#app.route('/hello', methods=['GET', 'POST'])
def hello():
return {'status': 200, 'message': 'custom_message',
'error': 'error_message', 'trace': 'trace_message',
'data': 'input_data'}
result
import requests
response = requests.get('http://localhost:5000/hello')
print(response.text)
{
"data": "input_data",
"error": "error_message",
"message": "custom_message",
"status": 200,
"trace": "trace_message"
}
I'm new to Python unit testing, and I want to mock calls to the boto3 3rd party library. Here's my stripped down code:
real_code.py:
import boto3
def temp_get_variable(var_name):
return boto3.client('ssm').get_parameter(Name=var_name)['Parameter']['Value']
test_real_code.py:
import unittest
from datetime import datetime
from unittest.mock import patch
import real_code
class TestRealCode(unittest.TestCase):
#patch('patching_config.boto3.client')
def test_get_variable(self, mock_boto_client):
response = {
'Parameter': {
'Name': 'MyTestParameterName',
'Type': 'String',
'Value': 'myValue',
'Version': 123,
'Selector': 'asdf',
'SourceResult': 'asdf',
'LastModifiedDate': datetime(2019, 7, 16),
'ARN': 'asdf'
}
}
mock_boto_client.get_variable.return_value = response
result_value = real_code.get_variable("MyTestParameterName")
self.assertEqual("myValue", result_value)
When I run it the test fails with
Expected :myValue
Actual :<MagicMock name='client().get_parameter().__getitem__().__getitem__()' id='2040071816528'>
What am I doing wrong? I thought by setting mock_boto_client.get_variable.return_value = response it would mock out the call and return my canned response instead. I don't understand why I am getting a MagicMock object instead of the return value I tried to set. I'd like to set up my test so that when the call to get_parameter is made with specific parameters, the mock returns the canned response I specified in the test.
There are two issues with your test code. The first is that when your mock object mock_boto_client called, it returns a new mock object. This means that the object that get_parameter() is being called on is different than the one you are attempting to set a return value on. You can have it return itself with the following:
mock_boto_client.return_value = mock_boto_client
You can also use a different mock object:
foo = MagicMock()
mock_boto_client.return_value = foo
The second issue that you have is that you are mocking the wrong method call. mock_boto_client.get_variable.return_value should be mock_boto_client.get_parameter.return_value. Here is the test updated and working:
import unittest
from datetime import datetime
from unittest.mock import patch
import real_code
class TestRealCode(unittest.TestCase):
#patch('boto3.client')
def test_get_variable(self, mock_boto_client):
response = {
'Parameter': {
'Name': 'MyTestParameterName',
'Type': 'String',
'Value': 'myValue',
'Version': 123,
'Selector': 'asdf',
'SourceResult': 'asdf',
'LastModifiedDate': datetime(2019, 7, 16),
'ARN': 'asdf'
}
}
mock_boto_client.return_value = mock_boto_client
mock_boto_client.get_parameter.return_value = response
result_value = real_code.get_variable("MyTestParameterName")
self.assertEqual("myValue", result_value)
I would like to marshal an object so that I get a response containing a list of links using Url, List and Nested from the Flask-Restful api.
job_link_fields = {
'href': restful.fields.Url('ep1', absolute=False),
'rel': restful.fields.Url('ep2', absolute=False)
}
job_fields = {
'name': restful.fields.String,
'links': restful.fields.List(restful.fields.Nested(job_link_fields))
}
class JobDao():
def __init__(self, id, job):
self.name = job['name']
self.links = [{'rel': 'jobs', 'id': id},
{'rel': 'jobs', 'id': id}]
class Job(restful.Resource):
#marshal_with(job_fields)
def get(self, id):
return JobDao(id, jobs[id-1])
But in the Url class, I need to specify the endpoint in the constructor which prevents me from adding differend job_link_fields in the List. How can I create a list of link?