Cloud testing platforms (BrowserStack, Sauce Labs) in Selenium Python

Introduction

Cloud testing platforms let you test your website or app on many browsers and devices without owning them. They save time and money.

You want to check if your website works on different browsers like Chrome, Firefox, Safari.

You need to test your app on mobile devices you don't have.

You want to run tests in parallel to finish faster.

You want to avoid setting up many test machines yourself.

You want to see screenshots or videos of your tests running remotely.

Syntax

Selenium Python

from selenium import webdriver
from selenium.webdriver.common.desired_capabilities import DesiredCapabilities

# Example for BrowserStack
desired_cap = DesiredCapabilities.CHROME.copy()
desired_cap['browser'] = 'Chrome'
desired_cap['browser_version'] = 'latest'
desired_cap['os'] = 'Windows'
desired_cap['os_version'] = '10'
desired_cap['name'] = 'Sample Test'

username = 'YOUR_USERNAME'
access_key = 'YOUR_ACCESS_KEY'
remote_url = f'https://{username}:{access_key}@hub-cloud.browserstack.com/wd/hub'

driver = webdriver.Remote(
    command_executor=remote_url,
    desired_capabilities=desired_cap
)

# Use driver as usual
# driver.get('https://example.com')

# driver.quit()

Replace YOUR_USERNAME and YOUR_ACCESS_KEY with your actual credentials.

Desired capabilities tell the cloud platform which browser and OS to use.

Examples

This example shows how to test on Firefox browser on Mac OS.

Selenium Python

desired_cap = DesiredCapabilities.FIREFOX.copy()
desired_cap['browser'] = 'Firefox'
desired_cap['browser_version'] = 'latest'
desired_cap['os'] = 'OS X'
desired_cap['os_version'] = 'Monterey'
desired_cap['name'] = 'Firefox Test on Mac'

# This runs the test on latest Firefox on Mac OS Monterey

This example shows testing on a real mobile device using BrowserStack.

Selenium Python

desired_cap = DesiredCapabilities.CHROME.copy()
desired_cap['browser'] = 'Chrome'
desired_cap['browser_version'] = 'latest'
desired_cap['os'] = 'Android'
desired_cap['os_version'] = '12.0'
desired_cap['device'] = 'Samsung Galaxy S22'
desired_cap['real_mobile'] = 'true'
desired_cap['name'] = 'Mobile Test on Samsung'

# This runs the test on a real Samsung Galaxy S22 device

Sample Program

This script connects to BrowserStack, opens Google homepage, checks the page title contains 'Google', and then closes the browser.

Selenium Python

from selenium import webdriver
from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
import time

# Setup desired capabilities for BrowserStack
desired_cap = DesiredCapabilities.CHROME.copy()
desired_cap['browser'] = 'Chrome'
desired_cap['browser_version'] = 'latest'
desired_cap['os'] = 'Windows'
desired_cap['os_version'] = '10'
desired_cap['name'] = 'Simple Google Test'

# Your BrowserStack credentials
username = 'YOUR_USERNAME'
access_key = 'YOUR_ACCESS_KEY'
remote_url = f'https://{username}:{access_key}@hub-cloud.browserstack.com/wd/hub'

# Create remote WebDriver
print('Starting remote WebDriver session...')
driver = webdriver.Remote(
    command_executor=remote_url,
    desired_capabilities=desired_cap
)

try:
    print('Opening Google homepage...')
    driver.get('https://www.google.com')
    time.sleep(3)  # Wait to see the page

    title = driver.title
    print(f'Page title is: {title}')

    assert 'Google' in title, 'Title does not contain Google'
    print('Assertion passed: Title contains Google')

finally:
    print('Quitting driver...')
    driver.quit()

Important Notes

Tests run on cloud platforms may be slower than local because of network delay.

Keep your credentials secret and do not share them publicly.

Use parallel testing features of these platforms to run many tests at once and save time.

Summary

Cloud testing platforms let you test on many browsers and devices without owning them.

You write Selenium tests as usual but connect to a remote URL with your credentials.

Set desired capabilities to choose browser, OS, and device for your test.

Practice

1. What is the main advantage of using cloud testing platforms like BrowserStack or Sauce Labs for Selenium tests?

easy

A. You do not need to write any Selenium code

B. They automatically fix bugs in your code

C. Tests run only on your local machine

D. You can test on many browsers and devices without owning them

Solution

1. Step 1: Understand cloud testing platform purpose

   Cloud platforms provide access to many browsers and devices remotely.

2. Step 2: Compare options

   Only the option stating 'You can test on many browsers and devices without owning them' correctly states the main advantage; others are incorrect or unrelated.

3. Final Answer:

   You can test on many browsers and devices without owning them -> Option D

4. Quick Check:

   Cloud testing = remote multi-browser/device access [OK]

Hint: Cloud platforms = test many devices remotely [OK]

Common Mistakes:

• Thinking tests run locally only
• Believing cloud platforms fix code bugs
• Assuming no Selenium code is needed

2. Which of the following is the correct way to specify the remote WebDriver URL for BrowserStack in Python Selenium?

easy

A. driver = webdriver.Remote(command_executor='https://hub-cloud.browserstack.com/wd/hub', desired_capabilities=capabilities)

B. driver = webdriver.Chrome('https://hub-cloud.browserstack.com/wd/hub')

C. driver = webdriver.Firefox('browserstack.com')

D. driver = webdriver.Remote('http://localhost:4444/wd/hub')

Solution

1. Step 1: Identify correct Remote WebDriver syntax

   Using webdriver.Remote with command_executor URL and capabilities is correct for BrowserStack.

2. Step 2: Check other options

   Options using Firefox or Chrome constructors with URLs are incorrect; the option with localhost URL is also wrong.

3. Final Answer:

   driver = webdriver.Remote(command_executor='https://hub-cloud.browserstack.com/wd/hub', desired_capabilities=capabilities) -> Option A

4. Quick Check:

   Remote WebDriver + BrowserStack URL = driver = webdriver.Remote(command_executor='https://hub-cloud.browserstack.com/wd/hub', desired_capabilities=capabilities) [OK]

Hint: Use webdriver.Remote with BrowserStack URL [OK]

Common Mistakes:

• Using local URLs instead of BrowserStack URL
• Calling Chrome or Firefox constructors with URLs
• Omitting desired capabilities

3. Given this Python Selenium code snippet for Sauce Labs, what will be printed if the test runs successfully?

from selenium import webdriver
caps = {
  'browserName': 'chrome',
  'platformName': 'Windows 10',
  'browserVersion': 'latest'
}
driver = webdriver.Remote(
  command_executor='https://username:[e-mail]:443/wd/hub',
  desired_capabilities=caps
)
driver.get('https://example.com')
print(driver.title)
driver.quit()

medium

A. An error about missing local Chrome driver

B. The title of https://example.com page

C. Empty string

D. Sauce Labs login page title

Solution

1. Step 1: Understand remote driver usage

   The code uses Sauce Labs remote URL with correct capabilities, so it runs on Sauce Labs cloud.

2. Step 2: Analyze driver.get and print

   driver.get loads example.com, and driver.title prints its page title.

3. Final Answer:

   The title of https://example.com page -> Option B

4. Quick Check:

   Remote driver loads page title = The title of https://example.com page [OK]

Hint: Remote driver prints page title, not errors [OK]

Common Mistakes:

• Expecting local driver errors
• Thinking remote driver prints login page
• Assuming empty title without loading

4. You wrote this code to run tests on BrowserStack but get a connection error:

driver = webdriver.Remote(
  command_executor='https://hub-cloud.browserstack.com/wd/hub',
  desired_capabilities=capabilities
)

What is the most likely cause and fix?

medium

A. Missing username and access key in URL; add them as https://username:[e-mail]/wd/hub

B. Wrong browser name in capabilities; change to 'firefox'

C. Local WebDriver server not running; start Selenium server locally

D. Use HTTP instead of HTTPS in URL

Solution

1. Step 1: Identify connection error cause

   BrowserStack requires authentication via username and access key in the URL.

2. Step 2: Fix URL with credentials

   Add username and access key before the host in the URL to authenticate properly.

3. Final Answer:

   Missing username and access key in URL; add them as https://username:[e-mail]/wd/hub -> Option A

4. Quick Check:

   Authentication URL format fixes connection [OK]

Hint: Add username:accesskey@ in URL for BrowserStack [OK]

Common Mistakes:

• Ignoring authentication in remote URL
• Changing browser name without cause
• Assuming local server needed for cloud

5. You want to run a Selenium test on BrowserStack for a mobile device with these requirements: Android 13, Chrome browser, and device name 'Samsung Galaxy S22'. Which desired capabilities dictionary is correct?

hard

A. {
'platformName': 'Android',
'platformVersion': '12',
'browserName': 'Chrome',
'deviceName': 'Samsung Galaxy S22'
}

B. {
'platformName': 'Windows',
'platformVersion': '13',
'browserName': 'Chrome',
'deviceName': 'Samsung Galaxy S22'
}

C. {
'platformName': 'Android',
'platformVersion': '13',
'browserName': 'Chrome',
'deviceName': 'Samsung Galaxy S22'
}

D. {
'platformName': 'Android',
'browserName': 'Firefox',
'deviceName': 'Samsung Galaxy S22'
}

Solution

1. Step 1: Match platform and version

   Android 13 is required, so platformName must be 'Android' and platformVersion '13'.

2. Step 2: Check browser and device name

   Browser must be 'Chrome' and deviceName 'Samsung Galaxy S22' exactly.

3. Step 3: Eliminate incorrect options

   The option with platformVersion '12' has wrong version; the one with 'Windows' has wrong platform; the one with 'Firefox' and no version has wrong browser and missing version.

4. Final Answer:

   { 'platformName': 'Android', 'platformVersion': '13', 'browserName': 'Chrome', 'deviceName': 'Samsung Galaxy S22' } -> Option C

5. Quick Check:

   Correct platform, version, browser, device = { 'platformName': 'Android', 'platformVersion': '13', 'browserName': 'Chrome', 'deviceName': 'Samsung Galaxy S22' } [OK]

Hint: Match all capability keys exactly for device testing [OK]

Common Mistakes:

• Using wrong platform or version
• Choosing wrong browser name
• Missing platformVersion key