Verify login functionality with valid credentials

Preconditions (2)

Step 1: Enter 'user@example.com' in the email input field

Step 2: Enter 'Password123' in the password input field

Step 3: Click the 'Login' button

✅ Expected Result: User is redirected to the dashboard page and sees a welcome message

Automation Requirements - Selenium with Python

Assertions Needed:

Verify the current URL is the dashboard URL

Verify the welcome message is displayed on the dashboard

Best Practices:

Use explicit waits to wait for elements to be visible or clickable

Use meaningful locators like ID or name attributes

Organize code using Page Object Model for maintainability

Automated Solution

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 LoginPage:
    def __init__(self, driver):
        self.driver = driver
        self.email_input = (By.ID, 'email')
        self.password_input = (By.ID, 'password')
        self.login_button = (By.ID, 'loginBtn')

    def enter_email(self, email):
        WebDriverWait(self.driver, 10).until(EC.visibility_of_element_located(self.email_input)).send_keys(email)

    def enter_password(self, password):
        WebDriverWait(self.driver, 10).until(EC.visibility_of_element_located(self.password_input)).send_keys(password)

    def click_login(self):
        WebDriverWait(self.driver, 10).until(EC.element_to_be_clickable(self.login_button)).click()

class DashboardPage:
    def __init__(self, driver):
        self.driver = driver
        self.welcome_message = (By.ID, 'welcomeMsg')

    def is_welcome_message_displayed(self):
        return WebDriverWait(self.driver, 10).until(EC.visibility_of_element_located(self.welcome_message)).is_displayed()

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

    def test_valid_login(self):
        login_page = LoginPage(self.driver)
        login_page.enter_email('user@example.com')
        login_page.enter_password('Password123')
        login_page.click_login()

        WebDriverWait(self.driver, 10).until(EC.url_contains('/dashboard'))
        self.assertIn('/dashboard', self.driver.current_url)

        dashboard_page = DashboardPage(self.driver)
        self.assertTrue(dashboard_page.is_welcome_message_displayed())

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

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

This test script uses Selenium with Python and unittest framework.

We define two page classes: LoginPage and DashboardPage to organize locators and actions, following the Page Object Model.

In test_valid_login, we enter the email and password, click login, then wait for the dashboard URL and check the welcome message is visible.

Explicit waits ensure elements are ready before interacting, avoiding flaky tests.

The setUp and tearDown methods open and close the browser cleanly for each test.

Common Mistakes - 3 Pitfalls

Using time.sleep() instead of explicit waits

Using brittle XPath locators that rely on full element paths

Not verifying the expected page or element after login

Bonus Challenge

Now add data-driven testing with 3 different sets of valid credentials

Show Hint