Browser profile configuration in Selenium Python - Build an Automation Script

Configure Firefox browser profile to disable notifications and verify settings

Preconditions (2)

Step 1: Create a new Firefox profile

Step 2: Set the profile preference to disable browser notifications

Step 3: Launch Firefox browser with this profile

Step 4: Navigate to https://www.example.com

Step 5: Verify that the browser notifications are disabled

✅ Expected Result: Firefox browser launches with notifications disabled and loads https://www.example.com successfully

Automation Requirements - Selenium with Python

Assertions Needed:

Verify the browser is launched with the custom profile

Verify the page title contains 'Example Domain' to confirm navigation

Verify that notifications are disabled by checking the profile preference

Best Practices:

Use FirefoxProfile to set preferences before browser launch

Use explicit waits if needed for page load

Use assertions from unittest or pytest for validation

Close the browser after test to free resources

Automated Solution

Selenium Python

from selenium import webdriver
from selenium.webdriver.firefox.options import Options
import unittest

class TestFirefoxProfile(unittest.TestCase):
    def setUp(self):
        # Create Firefox profile
        self.profile = webdriver.FirefoxProfile()
        # Disable notifications
        self.profile.set_preference("dom.webnotifications.enabled", False)
        self.profile.update_preferences()

        options = Options()
        # Launch Firefox with the custom profile
        self.driver = webdriver.Firefox(firefox_profile=self.profile, options=options)

    def test_notifications_disabled(self):
        self.driver.get("https://www.example.com")
        # Assert page title contains 'Example Domain'
        self.assertIn("Example Domain", self.driver.title)
        # Verify the preference is set (indirectly, since direct check is not possible via WebDriver)
        # We rely on profile setting correctness here

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

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

This test script uses Selenium with Python's unittest framework.

In setUp, we create a Firefox profile and set the preference dom.webnotifications.enabled to False to disable notifications.

We launch Firefox with this profile.

The test navigates to https://www.example.com and asserts the page title contains 'Example Domain' to confirm navigation.

Direct verification of notification settings via WebDriver is not possible, so we trust the profile setting.

Finally, tearDown closes the browser to clean up.

Common Mistakes - 4 Pitfalls

Not setting the profile preferences before launching the browser

Using deprecated FirefoxProfile API or incorrect method names

Not closing the browser after test execution

Trying to verify browser preferences directly via WebDriver commands

Bonus Challenge

Now add data-driven testing with 3 different Firefox profile preferences to disable notifications, disable images, and set a custom homepage

Show Hint

Practice

1. What is the main purpose of configuring a browser profile in Selenium tests?

easy

A. To write test cases faster

B. To customize browser settings before running tests

C. To increase the speed of Selenium WebDriver

D. To change the programming language of the test

Solution

1. Step 1: Understand browser profile role

   A browser profile allows setting preferences like homepage, notifications, or extensions before tests run.

2. Step 2: Identify the main purpose

   This customization helps simulate different user environments during testing.

3. Final Answer:

   To customize browser settings before running tests -> Option B

4. Quick Check:

   Browser profile = Customize settings [OK]

Hint: Browser profile changes browser setup before tests [OK]

Common Mistakes:

• Thinking it speeds up test execution
• Confusing profile with test case writing
• Believing it changes test language

2. Which of the following is the correct way to set a Firefox browser preference for disabling notifications using Selenium in Python?

easy

A. profile.set_preference('dom.webnotifications.enabled', False)

B. profile.setPreference('dom.webnotifications.enabled', 'false')

C. profile.set_preference('dom.webnotifications.enabled', 'False')

D. profile.set_preference('dom.webnotifications.enabled', 0)

Solution

1. Step 1: Check method name and argument types

   The correct method is set_preference with lowercase 'p' and boolean False (not string).

2. Step 2: Validate option values

   profile.set_preference('dom.webnotifications.enabled', False) uses correct method and boolean False, which disables notifications properly.

3. Final Answer:

   profile.set_preference('dom.webnotifications.enabled', False) -> Option A

4. Quick Check:

   Correct method + boolean False = profile.set_preference('dom.webnotifications.enabled', False) [OK]

Hint: Use set_preference with exact method name and boolean values [OK]

Common Mistakes:

• Using wrong method name like setPreference
• Passing boolean as string 'False'
• Using integer 0 instead of boolean False

3. Consider this Python code snippet configuring a Firefox profile:

from selenium.webdriver.firefox.firefox_profile import FirefoxProfile
profile = FirefoxProfile()
profile.set_preference('browser.startup.homepage', 'https://example.com')
profile.set_preference('dom.webnotifications.enabled', False)
profile.update_preferences()

print(profile.default_preferences['browser.startup.homepage'])

What will be printed when this code runs?

medium

A. https://example.com

B. None

C. KeyError

D. about:blank

Solution

1. Step 1: Understand FirefoxProfile attributes

   The default_preferences attribute is internal and not updated by set_preference. It may not contain the key.

2. Step 2: Predict print behavior

   Accessing profile.default_preferences['browser.startup.homepage'] will raise a KeyError because this key is not in default_preferences.

3. Final Answer:

   KeyError -> Option C

4. Quick Check:

   Accessing missing key = KeyError [OK]

Hint: Access only updated prefs, not default_preferences dict [OK]

Common Mistakes:

• Assuming set_preference updates default_preferences
• Expecting print to show new homepage URL
• Ignoring that KeyError occurs on missing dict key

4. You wrote this code to disable Firefox notifications but it still shows notifications during tests:

profile = FirefoxProfile()
profile.set_preference('dom.webnotifications.enabled', 'false')
profile.update_preferences()

What is the likely cause of this problem?

medium

A. The method update_preferences() is deprecated and should be removed

B. Missing call to profile.save() before using profile

C. Notifications cannot be disabled via profile settings

D. The preference value should be boolean False, not string 'false'

Solution

1. Step 1: Check preference value type

   The value 'false' is a string, but the preference expects a boolean False to disable notifications.

2. Step 2: Understand effect of wrong type

   Passing string 'false' does not disable notifications, so they still appear.

3. Final Answer:

   The preference value should be boolean False, not string 'false' -> Option D

4. Quick Check:

   Boolean False needed, not string 'false' [OK]

Hint: Use boolean False, not string, to disable prefs [OK]

Common Mistakes:

• Using string 'false' instead of boolean False
• Thinking update_preferences() is deprecated
• Believing notifications can't be disabled

5. You want to test your website's behavior when the browser homepage is set to 'https://testsite.com' and notifications are disabled. Which code snippet correctly configures the Firefox profile and launches the browser with these settings?

hard

A. profile = FirefoxProfile()
profile.set_preference('browser.startup.homepage', 'https://testsite.com')
profile.set_preference('dom.webnotifications.enabled', False)
profile.update_preferences()
driver = webdriver.Firefox(firefox_profile=profile)

B. profile = FirefoxProfile()
profile.set_preference('browser.startup.homepage', 'https://testsite.com')
profile.set_preference('dom.webnotifications.enabled', 'False')
driver = webdriver.Firefox(profile)

C. profile = FirefoxProfile()
profile.set_preference('browser.startup.homepage', 'https://testsite.com')
profile.set_preference('dom.webnotifications.enabled', False)
driver = webdriver.Firefox(profile=profile)

D. profile = FirefoxProfile()
profile.set_preference('browser.startup.homepage', 'https://testsite.com')
profile.set_preference('dom.webnotifications.enabled', False)
profile.update_preferences()
driver = webdriver.Firefox(profile)

Solution

1. Step 1: Set preferences correctly

   Use set_preference with correct keys and boolean False for notifications.

2. Step 2: Update preferences and pass profile correctly

   Call update_preferences() and pass profile as firefox_profile=profile to WebDriver.

3. Final Answer:

   Code snippet in Option A correctly sets preferences, updates them, and launches Firefox with profile -> Option A

4. Quick Check:

   Set prefs + update + firefox_profile param = profile = FirefoxProfile() profile.set_preference('browser.startup.homepage', 'https://testsite.com') profile.set_preference('dom.webnotifications.enabled', False) profile.update_preferences() driver = webdriver.Firefox(firefox_profile=profile) [OK]

Hint: Call update_preferences() and pass firefox_profile param [OK]

Common Mistakes:

• Passing profile without keyword argument
• Using string 'False' instead of boolean False
• Forgetting update_preferences() call