Fixtures for browser setup/teardown in Selenium Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of pytest fixture with browser setup

What will be the output of the following pytest test when run?

Note: The fixture opens a browser, navigates to example.com, then closes the browser after the test.

Selenium Python

import pytest
from selenium import webdriver

@pytest.fixture
 def browser():
  driver = webdriver.Chrome()
  driver.get('https://example.com')
  yield driver
  driver.quit()

def test_title(browser):
  assert 'Example Domain' in browser.title
  print('Test Passed')

A Test Passed printed and test passes

B Test Passed printed but test fails with AssertionError

C No output printed, test passes silently

D Test fails with WebDriverException due to missing driver

💡 Hint

The fixture yields the driver after opening the page, so the test can access the page title.

The fixture sets up the browser and navigates to example.com. The test asserts the title contains 'Example Domain', which is true, so the assertion passes and 'Test Passed' is printed. The fixture then quits the browser after the test.

❓ assertion

intermediate

Correct assertion to verify browser is closed after test

Given a pytest fixture that opens and closes a browser, which assertion correctly verifies the browser is closed after the test?

Selenium Python

import pytest
from selenium import webdriver

@pytest.fixture
 def browser():
  driver = webdriver.Chrome()
  yield driver
  driver.quit()

def test_browser_closed(browser):
  pass  # Which assertion below is correct here?

A assert browser.current_url == ''

B assert browser.session_id is None

C assert browser.title == ''

D assert browser is None

💡 Hint

When the browser is closed, the session_id becomes None.

After driver.quit(), the session_id attribute becomes None indicating the browser session is closed. Other attributes like current_url or title raise exceptions or remain unchanged until accessed.

🔧 Debug

advanced

Identify the bug in fixture teardown

What is the bug in this pytest fixture for browser setup and teardown?

Selenium Python

import pytest
from selenium import webdriver

@pytest.fixture
 def browser():
  driver = webdriver.Chrome()
  driver.get('https://example.com')
  yield driver
  driver.close()  # Bug here

def test_example(browser):
  assert 'Example Domain' in browser.title

A driver.close() closes only the current window, not the browser session, causing resource leaks

B driver.close() raises an exception because it is called after yield

C driver.close() should be replaced with driver.quit() to avoid syntax error

D No bug, the fixture works correctly

💡 Hint

driver.close() and driver.quit() behave differently in Selenium.

driver.close() closes the current browser window but does not end the WebDriver session, which can leave the browser process running. driver.quit() properly ends the session and closes all windows.

❓ framework

advanced

Best practice for browser fixture scope in pytest

Which pytest fixture scope is best to use for browser setup/teardown to speed up multiple UI tests without side effects?

A scope='class' to open browser once per test class

B scope='function' to open and close browser for each test function

C scope='module' to open browser once per test module

D scope='session' to open browser once per test session

💡 Hint

Consider test isolation and speed trade-offs.

Using scope='module' opens the browser once per module, balancing speed and isolation. 'function' is slow, 'session' risks side effects across unrelated tests, 'class' is less common and depends on test organization.

🧠 Conceptual

expert

Why use yield in pytest fixtures for browser setup?

Why is the yield statement preferred over return in pytest fixtures that setup and teardown a browser?

A Yield returns the browser object faster than return

B Return cannot be used in fixtures, only yield is allowed

C Return causes the fixture to run multiple times, yield runs once

D Yield allows running teardown code after the test finishes, return does not

💡 Hint

Think about how pytest manages setup and teardown with fixtures.

Yield pauses the fixture to run the test, then resumes to run teardown code after the test. Return ends the fixture immediately, so no teardown code runs after the test.

Practice

1. What is the main purpose of using a fixture for browser setup and teardown in Selenium tests?

easy

A. To avoid using assertions in tests

B. To write test cases faster without any setup

C. To automate opening and closing the browser before and after tests

D. To run tests only on one browser type

Solution

1. Step 1: Understand fixture role

   Fixtures help prepare the environment before tests and clean up after tests.

2. Step 2: Apply to browser context

   In Selenium, this means opening the browser before tests and closing it after.

3. Final Answer:

   To automate opening and closing the browser before and after tests -> Option C

4. Quick Check:

   Fixture = setup + teardown automation [OK]

Hint: Fixtures handle setup and cleanup automatically [OK]

Common Mistakes:

• Thinking fixtures replace test cases
• Believing fixtures remove need for assertions
• Assuming fixtures limit browser types

2. Which of the following is the correct way to define a pytest fixture for browser setup and teardown using yield?

easy

A. def browser():
driver = webdriver.Chrome()
yield driver
driver.quit()

B. def browser():
driver = webdriver.Chrome()
driver.quit()
yield driver

C. def browser():
yield webdriver.Chrome()
driver.quit()

D. def browser():
driver = webdriver.Chrome()
driver.close()
yield driver

Solution

1. Step 1: Understand yield usage in fixtures

   Yield separates setup (before yield) and teardown (after yield).

2. Step 2: Check correct order

   Setup: create driver; yield it; teardown: quit driver.

3. Final Answer:

   def browser(): driver = webdriver.Chrome() yield driver driver.quit() -> Option A

4. Quick Check:

   Setup before yield, teardown after yield [OK]

Hint: Setup before yield, teardown after yield in fixture [OK]

Common Mistakes:

• Calling quit before yield
• Using driver.close() instead of driver.quit() for teardown
• Yielding before creating driver

3. Given this fixture and test code, what will be printed when the test runs?

import pytest
from selenium import webdriver

@pytest.fixture
def browser():
    driver = webdriver.Chrome()
    print('Setup browser')
    yield driver
    print('Teardown browser')
    driver.quit()

def test_example(browser):
    print('Running test')

medium

A. Running test only

B. Running test\nSetup browser\nTeardown browser

C. Setup browser\nTeardown browser\nRunning test

D. Setup browser\nRunning test\nTeardown browser

Solution

1. Step 1: Trace fixture execution order

   Fixture runs setup code before yield, then test runs, then fixture runs teardown after yield.

2. Step 2: Match print statements order

   Prints 'Setup browser', then 'Running test', then 'Teardown browser'.

3. Final Answer:

   Setup browser\nRunning test\nTeardown browser -> Option D

4. Quick Check:

   Setup -> Test -> Teardown order [OK]

Hint: Fixture setup prints before test, teardown prints after [OK]

Common Mistakes:

• Assuming teardown runs before test
• Ignoring yield separates setup and teardown
• Thinking prints run all before test

4. What is wrong with this fixture code for browser setup and teardown?

@pytest.fixture
def browser():
    driver = webdriver.Chrome()
    driver.quit()
    yield driver

medium

A. Missing import statement for webdriver

B. Calling driver.quit() before yield closes browser too early

C. Yield should be inside a try-except block

D. Fixture should return driver instead of yield

Solution

1. Step 1: Analyze order of operations

   driver.quit() is called before yield, so browser closes before test uses it.

2. Step 2: Understand yield role

   Yield should come before teardown to keep browser open during test.

3. Final Answer:

   Calling driver.quit() before yield closes browser too early -> Option B

4. Quick Check:

   Teardown must be after yield [OK]

Hint: Teardown code must be after yield in fixture [OK]

Common Mistakes:

• Calling quit before yield
• Confusing yield with return
• Ignoring fixture import requirements

5. You want to run multiple tests using the same browser instance to save time. How should you modify the fixture to achieve this?

hard

A. Change fixture scope to 'module' so browser opens once per module

B. Add driver.quit() before yield to close browser early

C. Remove yield and return driver directly

D. Create a new fixture for each test to isolate browser

Solution

1. Step 1: Understand fixture scopes

   Default scope is 'function' which runs fixture per test; 'module' runs once per file.

2. Step 2: Apply scope to reuse browser

   Setting scope='module' opens browser once for all tests in module, saving time.

3. Final Answer:

   Change fixture scope to 'module' so browser opens once per module -> Option A

4. Quick Check:

   Fixture scope controls reuse [OK]

Hint: Use scope='module' to share browser across tests [OK]

Common Mistakes:

• Closing browser before tests run
• Removing yield breaks setup/teardown
• Creating new fixture per test wastes time