Interview preparation for testers in Testing Fundamentals - Test Execution Trace

Test Overview

This test simulates a simple interview question scenario where the tester verifies the presence of key UI elements on a sample login page. It checks if the username field, password field, and login button are visible and enabled, ensuring the page is ready for user interaction.

Test Code - Selenium with unittest

Testing Fundamentals

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
import unittest

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

    def test_login_page_elements(self):
        driver = self.driver
        wait = WebDriverWait(driver, 10)

        username = wait.until(EC.presence_of_element_located((By.ID, 'username')))
        password = wait.until(EC.presence_of_element_located((By.ID, 'password')))
        login_button = wait.until(EC.presence_of_element_located((By.ID, 'login-btn')))

        self.assertTrue(username.is_displayed(), 'Username field should be visible')
        self.assertTrue(password.is_displayed(), 'Password field should be visible')
        self.assertTrue(login_button.is_enabled(), 'Login button should be enabled')

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

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

Execution Trace - 9 Steps

Step	Action	System State	Assertion	Result
1	Test starts and Chrome browser opens	Chrome browser window is open and ready	-	PASS
2	Navigates to 'https://example.com/login'	Login page loads with username, password fields and login button	-	PASS
3	Waits for username field with ID 'username' to be present	Username input field is present in DOM	Username field is present	PASS
4	Waits for password field with ID 'password' to be present	Password input field is present in DOM	Password field is present	PASS
5	Waits for login button with ID 'login-btn' to be present	Login button is present in DOM	Login button is present	PASS
6	Checks if username field is visible	Username field is visible on page	Username field is displayed	PASS
7	Checks if password field is visible	Password field is visible on page	Password field is displayed	PASS
8	Checks if login button is enabled	Login button is enabled and clickable	Login button is enabled	PASS
9	Test ends and browser closes	Browser window is closed	-	PASS

Failure Scenario

Failing Condition: Login button with ID 'login-btn' is missing or disabled

Execution Trace Quiz - 3 Questions

What does the test verify about the login button?

A It is hidden from the user

B It is only present but disabled

C It is present and enabled

D It is clickable but not visible

Key Result

Always wait explicitly for elements to be present before interacting to avoid flaky tests and ensure reliable verification.