Authentication testing in Testing Fundamentals - Test Execution Trace

Test Overview

This test checks if a user can successfully log in with valid credentials and verifies that the welcome message appears after login.

Test Code - Selenium with unittest

Testing Fundamentals

import unittest
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

class TestAuthentication(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Chrome()
        self.driver.get('https://example.com/login')

    def test_valid_login(self):
        driver = self.driver
        username_input = WebDriverWait(driver, 10).until(
            EC.presence_of_element_located((By.ID, 'username'))
        )
        username_input.send_keys('validUser')

        password_input = driver.find_element(By.ID, 'password')
        password_input.send_keys('validPass123')

        login_button = driver.find_element(By.ID, 'login-button')
        login_button.click()

        welcome_message = WebDriverWait(driver, 10).until(
            EC.visibility_of_element_located((By.ID, 'welcome-msg'))
        )
        self.assertEqual(welcome_message.text, 'Welcome, validUser!')

    def tearDown(self):
        self.driver.quit()

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

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test starts and opens Chrome browser	Browser window opens at 'https://example.com/login' showing login form with username and password fields	—	PASS
2	Waits for username input field to be present and enters 'validUser'	Username input field is visible and filled with 'validUser'	—	PASS
3	Finds password input field and enters 'validPass123'	Password input field is visible and filled with 'validPass123'	—	PASS
4	Finds and clicks the login button	Login button clicked, page starts loading user dashboard	—	PASS
5	Waits for welcome message to be visible	Welcome message element with text 'Welcome, validUser!' is visible on the page	Check that welcome message text equals 'Welcome, validUser!'	PASS
6	Test ends and browser closes	Browser window closes	—	PASS

Failure Scenario

Failing Condition: Welcome message does not appear or text is incorrect after login

Execution Trace Quiz - 3 Questions

What does the test verify after clicking the login button?

A That the welcome message with correct username appears

B That the login button is disabled

C That the password field is cleared

D That the browser navigates to the homepage URL

Key Result

Always wait explicitly for elements to appear before interacting or asserting to avoid flaky tests.

Practice

1. What is the main goal of authentication testing in software testing?

easy

A. To verify that only valid users can access the system

B. To check the speed of the application

C. To test the user interface design

D. To validate database connections

Solution

1. Step 1: Understand authentication testing purpose

   Authentication testing focuses on verifying user identity before granting access.

2. Step 2: Compare options with this purpose

   Only To verify that only valid users can access the system matches this goal; others relate to different testing areas.

3. Final Answer:

   To verify that only valid users can access the system -> Option A

4. Quick Check:

   Authentication testing = verify valid users [OK]

Hint: Authentication = check valid user access [OK]

Common Mistakes:

• Confusing authentication with performance testing
• Thinking authentication tests UI elements
• Mixing authentication with database testing

2. Which of the following is the correct way to test a login form's authentication feature?

easy

A. Enter valid username and password, then check for successful login

B. Click random buttons without entering data

C. Only check if the login button is visible

D. Test the color of the login page background

Solution

1. Step 1: Identify valid test steps for authentication

   Testing authentication requires entering valid credentials and verifying access.

2. Step 2: Evaluate options for correctness

   Enter valid username and password, then check for successful login correctly describes this; others do not test authentication properly.

3. Final Answer:

   Enter valid username and password, then check for successful login -> Option A

4. Quick Check:

   Valid credentials test = successful login [OK]

Hint: Test with valid credentials for login success [OK]

Common Mistakes:

• Ignoring input fields and clicking randomly
• Testing only UI elements without input
• Confusing visual checks with authentication tests

3. Consider this test case for authentication:

Input: username='user1', password='wrongpass'
Expected: Login fails with error message 'Invalid credentials'

What will be the test result if the system allows login with these credentials?

medium

A. Test passes if error message is shown

B. Test passes because login is successful

C. Test is inconclusive without more data

D. Test fails because login should not succeed

Solution

1. Step 1: Analyze expected vs actual behavior

   The test expects login failure with an error message for wrong password.

2. Step 2: Compare actual system behavior

   If login succeeds with wrong password, it contradicts expected behavior, causing test failure.

3. Final Answer:

   Test fails because login should not succeed -> Option D

4. Quick Check:

   Wrong password login = test fail [OK]

Hint: Wrong password must fail login [OK]

Common Mistakes:

• Assuming any login success means pass
• Ignoring expected error messages
• Confusing test pass/fail logic

4. You wrote this test script for authentication:

def test_login():
    username = 'admin'
    password = 'admin123'
    result = login(username, password)
    assert result == False

What is the error in this test?

medium

A. The password variable is empty

B. The username variable is not defined

C. The assertion expects login to fail but credentials are valid

D. The login function is missing parentheses

Solution

1. Step 1: Understand test intent and data

   Username and password appear valid, so login should succeed (True).

2. Step 2: Check assertion correctness

   Assertion expects False (failure), which contradicts valid credentials, causing test error.

3. Final Answer:

   The assertion expects login to fail but credentials are valid -> Option C

4. Quick Check:

   Valid credentials expect True, not False [OK]

Hint: Match assertion with expected login result [OK]

Common Mistakes:

• Asserting wrong expected result
• Assuming variables undefined without checking
• Confusing function call syntax

5. You want to test a system that locks a user account after 3 failed login attempts. Which test case best verifies this feature?

hard

A. Login once with correct password and check access

B. Attempt login 3 times with wrong password, then check if account is locked

C. Try logging in with empty username and password

D. Check if password reset link is visible on login page

Solution

1. Step 1: Identify feature to test

   The feature locks account after 3 failed login attempts.

2. Step 2: Select test case matching feature

   Attempt login 3 times with wrong password, then check if account is locked tests exactly this by failing login 3 times and checking lock status.

3. Final Answer:

   Attempt login 3 times with wrong password, then check if account is locked -> Option B

4. Quick Check:

   3 failed attempts = account lock test [OK]

Hint: Test lock by 3 failed logins [OK]

Common Mistakes:

• Testing unrelated features like password reset
• Using correct password instead of failed attempts
• Ignoring the number of failed attempts