API test automation concepts in Testing Fundamentals - Test Execution Trace

Test Overview

This test sends a GET request to a sample API endpoint and verifies the response status code and content. It checks that the API returns the expected data, ensuring the API works correctly.

Test Code - unittest

Testing Fundamentals

import requests
import unittest

class TestSampleAPI(unittest.TestCase):
    def test_get_user(self):
        url = "https://jsonplaceholder.typicode.com/users/1"
        response = requests.get(url)
        self.assertEqual(response.status_code, 200)
        data = response.json()
        self.assertEqual(data["id"], 1)
        self.assertIn("username", data)

if __name__ == "__main__":
    unittest.main()

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test starts	Test runner initializes the test class and method	-	PASS
2	Sends GET request to https://jsonplaceholder.typicode.com/users/1	HTTP request sent to API server	-	PASS
3	Receives HTTP response from API	Response object contains status code and JSON data	Check response.status_code == 200	PASS
4	Parses JSON response body	JSON data loaded into a dictionary	Check data["id"] == 1	PASS
5	Verifies 'username' key exists in response data	Response JSON contains expected fields	Check 'username' in data	PASS
6	Test ends successfully	All assertions passed, test completes	-	PASS

Failure Scenario

Failing Condition: API returns a status code other than 200 or missing expected data fields

Execution Trace Quiz - 3 Questions

What does the test verify first after sending the GET request?

A The response time is less than 1 second

B The HTTP status code is 200

C The response contains a 'username' field

D The API endpoint URL is correct

Key Result

Always verify both the HTTP status code and the response content to ensure the API behaves as expected.