Authentication vulnerability testing in Testing Fundamentals - Test Execution Trace

Test Overview

This test checks if the login page properly blocks access when wrong credentials are used. It verifies that the system does not allow unauthorized users to log in.

Test Code - Selenium with Python 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 TestAuthenticationVulnerability(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Chrome()
        self.driver.get('https://example.com/login')

    def test_invalid_login(self):
        driver = self.driver
        # Wait for username field
        WebDriverWait(driver, 10).until(EC.presence_of_element_located((By.ID, 'username')))
        username_input = driver.find_element(By.ID, 'username')
        password_input = driver.find_element(By.ID, 'password')
        login_button = driver.find_element(By.ID, 'login-btn')

        # Enter invalid credentials
        username_input.send_keys('wronguser')
        password_input.send_keys('wrongpass')
        login_button.click()

        # Wait for error message
        error_element = WebDriverWait(driver, 10).until(
            EC.presence_of_element_located((By.ID, 'error-msg'))
        )

        # Verify error message text
        self.assertEqual(error_element.text, 'Invalid username or password.')

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

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

Execution Trace - 8 Steps

Step	Action	System State	Assertion	Result
1	Test starts and opens Chrome browser	Browser is open at 'https://example.com/login' page showing login form with username, password fields and login button	-	PASS
2	Waits until username input field is present	Login form is fully loaded with username input visible	Username input field is present	PASS
3	Finds username, password input fields and login button	All required elements located by their IDs	Elements found successfully	PASS
4	Enters invalid username 'wronguser' and password 'wrongpass'	Input fields filled with invalid credentials	-	PASS
5	Clicks the login button	Login form submitted, page processes login attempt	-	PASS
6	Waits for error message element with ID 'error-msg' to appear	Error message displayed on page	Error message element is present	PASS
7	Checks that error message text equals 'Invalid username or password.'	Error message text visible to user	Error message text matches expected	PASS
8	Test ends and browser closes	Browser closed, test complete	-	PASS

Failure Scenario

Failing Condition: Error message element does not appear after submitting invalid credentials

Execution Trace Quiz - 3 Questions

What does the test verify after clicking the login button with wrong credentials?

A That the user is redirected to the homepage

B That the password field is cleared

C That an error message saying 'Invalid username or password.' appears

D That the login button is disabled

Key Result

Always wait explicitly for elements that appear after actions, like error messages, to avoid flaky tests and ensure the application properly handles invalid inputs.