Error guessing in Testing Fundamentals - Test Execution Trace

Test Overview

This test simulates error guessing by deliberately entering invalid input to check if the system handles errors gracefully. It verifies that the application shows an appropriate error message when invalid data is submitted.

Test Code - Selenium

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

    def test_invalid_login(self):
        driver = self.driver
        # Find username field and enter invalid username
        username = WebDriverWait(driver, 10).until(
            EC.presence_of_element_located((By.ID, 'username'))
        )
        username.clear()
        username.send_keys('invalid_user!@#')

        # Find password field and enter invalid password
        password = driver.find_element(By.ID, 'password')
        password.clear()
        password.send_keys('wrongpass123')

        # Click login button
        login_button = driver.find_element(By.ID, 'loginBtn')
        login_button.click()

        # Wait for error message to appear
        error_msg = WebDriverWait(driver, 10).until(
            EC.visibility_of_element_located((By.ID, 'errorMessage'))
        )

        # Assert error message text
        self.assertEqual(error_msg.text, 'Invalid username or password.')

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

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

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Test starts and browser opens the login page	Browser displays the login page with username, password fields and login button	-	PASS
2	Find username field and enter invalid username 'invalid_user!@#'	Username field is filled with invalid characters	-	PASS
3	Find password field and enter invalid password 'wrongpass123'	Password field is filled with invalid password	-	PASS
4	Click the login button	Login button is clicked, form is submitted	-	PASS
5	Wait for error message to appear with id 'errorMessage'	Error message element is visible on the page	Verify error message text equals 'Invalid username or password.'	PASS

Failure Scenario

Failing Condition: Error message does not appear or text is different after submitting invalid credentials

Execution Trace Quiz - 3 Questions

What is the purpose of entering 'invalid_user!@#' in the username field?

A To check password strength

B To verify successful login

C To test how the system handles invalid input

D To clear the username field

Key Result

Error guessing tests help find hidden bugs by trying inputs that might cause the system to fail, ensuring robust error handling.