Running Selenium in CI pipeline in Selenium Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of Selenium WebDriver in headless mode

What will be the output when running this Selenium Python script in a CI pipeline with headless Chrome?

Selenium Python

from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.add_argument('--headless')
driver = webdriver.Chrome(options=options)
driver.get('https://example.com')
title = driver.title
driver.quit()
print(title)

A Example Domain

B selenium.common.exceptions.WebDriverException

C No output (script hangs)

D ChromeDriver not found error

💡 Hint

Headless mode allows Chrome to run without opening a window, so the page title can still be retrieved.

The script runs Chrome in headless mode, navigates to example.com, and prints the page title 'Example Domain'.

❓ Troubleshoot

intermediate

Fixing ChromeDriver version mismatch error in CI

In a CI pipeline, Selenium tests fail with the error: 'This version of ChromeDriver only supports Chrome version 90'. What is the best way to fix this?

A Remove the --headless argument from Chrome options

B Downgrade Selenium to an older version

C Update ChromeDriver to match the installed Chrome browser version

D Increase the timeout for WebDriver initialization

💡 Hint

ChromeDriver and Chrome browser versions must be compatible.

The error occurs because ChromeDriver version does not match the installed Chrome browser version. Updating ChromeDriver to the correct version resolves this.

❓ Configuration

advanced

Configuring Selenium to run with Firefox in CI

Which configuration snippet correctly sets up Selenium WebDriver to run Firefox in headless mode in a CI pipeline?

A

from selenium import webdriver
from selenium.webdriver.firefox.options import Options
options = Options()
options.headless = True
driver = webdriver.Firefox(options=options)

B

from selenium import webdriver
options = webdriver.FirefoxOptions()
options.add_argument('--headless')
driver = webdriver.Firefox(options=options)

C

from selenium import webdriver
options = webdriver.FirefoxOptions()
options.headless = True
driver = webdriver.Firefox(options=options)

D

from selenium import webdriver
from selenium.webdriver.firefox.options import Options
options = Options()
options.add_argument('--headless')
driver = webdriver.Firefox(options=options)

💡 Hint

Use the correct import and method to add headless argument for Firefox.

Option D correctly imports Options, adds '--headless' argument, and passes options to Firefox WebDriver.

🔀 Workflow

advanced

Best CI workflow step to run Selenium tests

In a CI pipeline, which step order ensures Selenium tests run reliably with Chrome in headless mode?

A Run Selenium tests -> Install Chrome -> Install ChromeDriver -> Cleanup

B Install Chrome -> Install ChromeDriver -> Run Selenium tests -> Cleanup

C Install ChromeDriver -> Install Chrome -> Run Selenium tests -> Cleanup

D Install Chrome -> Run Selenium tests -> Install ChromeDriver -> Cleanup

💡 Hint

Chrome and ChromeDriver must be installed before running tests.

Tests require Chrome and ChromeDriver installed first. Running tests before installation causes failure.

🧠 Conceptual

expert

Why use virtual display (Xvfb) in Selenium CI pipelines?

What is the main reason to use a virtual display like Xvfb when running Selenium tests in CI pipelines on Linux servers?

A To provide a graphical environment for browsers to run without a physical display

B To speed up browser startup time by caching display data

C To enable running tests in parallel on multiple CPU cores

D To automatically update browser drivers to the latest version

💡 Hint

Linux servers often lack a graphical desktop environment.

Xvfb creates a virtual framebuffer so browsers can run graphical tests without needing a real display.