Verify user login use case

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 with URL containing '/dashboard' and a welcome message 'Welcome, user!' is displayed

Automation Requirements - Selenium with Python

Assertions Needed:

Verify current URL contains '/dashboard'

Verify welcome message text is 'Welcome, user!'

Best Practices:

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

Use descriptive locators such as By.ID or By.CSS_SELECTOR

Organize code with setup and teardown methods

Use assertions from unittest or pytest frameworks

Automated Solution

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 TestUserLogin(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Chrome()
        self.driver.get('https://example.com/login')
        self.wait = WebDriverWait(self.driver, 10)

    def test_user_login(self):
        driver = self.driver
        wait = self.wait

        email_input = wait.until(EC.visibility_of_element_located((By.ID, 'email')))
        email_input.clear()
        email_input.send_keys('user@example.com')

        password_input = wait.until(EC.visibility_of_element_located((By.ID, 'password')))
        password_input.clear()
        password_input.send_keys('Password123!')

        login_button = wait.until(EC.element_to_be_clickable((By.ID, 'login-button')))
        login_button.click()

        wait.until(EC.url_contains('/dashboard'))
        self.assertIn('/dashboard', driver.current_url, 'URL does not contain /dashboard after login')

        welcome_message = wait.until(EC.visibility_of_element_located((By.ID, 'welcome-msg')))
        self.assertEqual(welcome_message.text, 'Welcome, user!', 'Welcome message text is incorrect')

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

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

The setUp method opens the browser and navigates to the login page before each test.

We use WebDriverWait with explicit waits to wait for the email and password fields to be visible before interacting with them. This avoids errors if the page loads slowly.

We locate elements by their id attributes, which is a reliable and fast locator strategy.

After entering credentials, we wait for the login button to be clickable and then click it.

We wait until the URL contains '/dashboard' to confirm navigation succeeded.

Finally, we check that the welcome message text matches exactly 'Welcome, user!'.

The tearDown method closes the browser after the test finishes.

This structure keeps tests clean, readable, and reliable.

Common Mistakes - 4 Pitfalls

Using time.sleep() instead of explicit waits

Using brittle XPath locators with absolute paths

Not clearing input fields before typing

Not verifying the correct page after login

Bonus Challenge

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

Show Hint