Making an API call and unit testing in Python

 This post is about mocking functions which have api calls.

Consider the following python function which makes an API call to the url www.testurl.com

import requests

def api_call_demo(name,telephone):
    # add queryParams (Replace this with your query params)
    queryParams = {
        'name': name,
        'address': telephone,
    }
    retry = 1
    retry_counter = 3
    # Replace this with the proper url
    url = "www.testurl.com"
    for retry in range(1, retry_counter):
        try:
            # make a http get call
            response = requests.get(url,
                                    params=queryParams,
                                    timeout=200.0,
                                    )
        # request error
        except (ConnectionError, ConnectionResetError) as cerr:
            print(f"Received error {cerr} for {url} on try {retry}", file=sys.stderr)

            if retry == retry_counter - 1:
                return None

            # continue retrying
            continue

        break

    if response is None or response.status_code != 200:
        return None

    if response.json() is not None:
        # Replace this to suit your http response
        print(response["data"])

If you would like to unit test this bit of code you would want to have something like this.

import unittest
import json
from unittest import mock
from requests import Response

from api import api_call_demo


def new_response(status_code, content):
    response = Response()
    response.status_code = status_code
    response_content = json.dumps(content)
    response._content = str.encode(response_content)
    return response


class TestMockCalls(unittest.TestCase):
    @mock.patch('requests.get')
    def test_api_call_demo(self, mock_requests):
        response_data = '{"data":"unit_testing"}'
        mock_requests.return_value = new_response(200, json.loads(response_data))
        api_call_demo("testname", "1234567890")

        #  Write assertions here