Request methods and status codes in Testing Fundamentals - Test Execution Trace

Test Overview

This test checks if a web API correctly handles a GET request and returns the expected status code 200, indicating success.

Test Code - unittest

Testing Fundamentals

import requests
import unittest

class TestAPIRequestMethods(unittest.TestCase):
    def test_get_request_status_code(self):
        url = "https://jsonplaceholder.typicode.com/posts/1"
        response = requests.get(url)
        self.assertEqual(response.status_code, 200)

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

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Test starts	Test framework initialized, ready to run test_get_request_status_code	—	PASS
2	Sends GET request to https://jsonplaceholder.typicode.com/posts/1	HTTP request sent to the API endpoint	—	PASS
3	Receives HTTP response from the server	Response object contains status code and data	—	PASS
4	Checks if response status code equals 200	Response status code is 200 OK	Assert response.status_code == 200	PASS
5	Test completes successfully	Test framework reports test passed	—	PASS

Failure Scenario

Failing Condition: The API returns a status code other than 200 (e.g., 404 or 500)

Execution Trace Quiz - 3 Questions

What HTTP method is used in this test?

A POST

B PUT

C GET

D DELETE

Key Result

Always verify that the API returns the expected status code for the request method used. This confirms the API behaves correctly for that operation.

Practice

1. Which HTTP request method is typically used to retrieve data from a server without changing it?

easy

A. PUT

B. POST

C. DELETE

D. GET

Solution

1. Step 1: Understand the purpose of HTTP methods

   GET is used to request data without modifying it, while POST, PUT, and DELETE change data on the server.

2. Step 2: Match method to action

   Since the question asks for retrieving data without changes, GET is the correct method.

3. Final Answer:

   GET -> Option D

4. Quick Check:

   Retrieve data = GET [OK]

Hint: GET always fetches data without side effects [OK]

Common Mistakes:

• Confusing POST with GET for data retrieval
• Thinking PUT or DELETE retrieve data
• Assuming GET modifies data

2. Which HTTP status code means the request was successful and the server returned the requested data?

easy

A. 200 OK

B. 404 Not Found

C. 500 Internal Server Error

D. 301 Moved Permanently

Solution

1. Step 1: Identify success status codes

   HTTP status codes starting with 2xx indicate success. 200 OK means the request succeeded and data is returned.

2. Step 2: Eliminate error and redirect codes

   404 means not found, 500 means server error, and 301 means redirect. These do not indicate success with data returned.

3. Final Answer:

   200 OK -> Option A

4. Quick Check:

   Success code = 200 OK [OK]

Hint: 200 means success and data returned [OK]

Common Mistakes:

• Choosing 404 thinking it means success
• Confusing 301 redirect with success
• Mixing client and server error codes

3. What will be the HTTP status code returned if a client sends a DELETE request to remove a resource successfully?

medium

A. 201 Created

B. 204 No Content

C. 400 Bad Request

D. 403 Forbidden

Solution

1. Step 1: Understand DELETE success codes

   A successful DELETE request usually returns 204 No Content, meaning the resource was deleted and no content is returned.

2. Step 2: Eliminate other codes

   201 Created is for resource creation, 400 Bad Request means client error, and 403 Forbidden means no permission.

3. Final Answer:

   204 No Content -> Option B

4. Quick Check:

   DELETE success = 204 No Content [OK]

Hint: DELETE success usually returns 204 No Content [OK]

Common Mistakes:

• Choosing 201 which is for creation
• Confusing 400 with success
• Thinking 403 means success

4. A test script sends a POST request to create a new user but receives a 405 Method Not Allowed status. What is the most likely cause?

medium

A. The server does not support the POST method on this URL

B. The user data is invalid

C. The server is down

D. The request timed out

Solution

1. Step 1: Understand 405 status meaning

   405 Method Not Allowed means the HTTP method used is not supported by the server for the requested URL.

2. Step 2: Eliminate other causes

   Invalid data usually causes 400 errors, server down causes 5xx errors, and timeout causes no response or 408.

3. Final Answer:

   The server does not support the POST method on this URL -> Option A

4. Quick Check:

   405 = Method not allowed [OK]

Hint: 405 means method not allowed on this URL [OK]

Common Mistakes:

• Thinking 405 means invalid data
• Confusing 405 with server errors
• Assuming timeout causes 405

5. During API testing, a PUT request to update a resource returns 409 Conflict. What should the tester check next?

hard

A. If the request method should be GET instead

B. If the request URL is incorrect

C. If the resource already exists and has conflicting changes

D. If the server is overloaded

Solution

1. Step 1: Understand 409 Conflict meaning

   409 Conflict means the request could not be completed due to a conflict with the current state of the resource, often caused by simultaneous updates.

2. Step 2: Identify what to check

   The tester should check if the resource exists and if there are conflicting changes that prevent the update.

3. Final Answer:

   If the resource already exists and has conflicting changes -> Option C

4. Quick Check:

   409 = Conflict with resource state [OK]

Hint: 409 means conflict with existing resource state [OK]

Common Mistakes:

• Assuming 409 means wrong URL
• Thinking 409 means server overload
• Confusing 409 with method errors