Docker-based Grid in Selenium Python - Test Execution Trace

Test Overview

This test uses Selenium with a Docker-based Selenium Grid to open a browser, navigate to a website, find a button by its ID, click it, and verify the page title changes as expected.

Test Code - Selenium

Selenium Python

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

# Connect to Selenium Grid running in Docker
options = webdriver.ChromeOptions()
driver = webdriver.Remote(
    command_executor='http://localhost:4444/wd/hub',
    options=options
)

try:
    driver.get('https://example.com')
    
    # Wait until button with id 'start-btn' is present
    wait = WebDriverWait(driver, 10)
    button = wait.until(EC.presence_of_element_located((By.ID, 'start-btn')))
    
    button.click()
    
    # Wait until title changes to expected value
    wait.until(EC.title_is('Started Page'))
    
    assert driver.title == 'Started Page', f"Expected title 'Started Page' but got '{driver.title}'"
finally:
    driver.quit()

Execution Trace - 7 Steps

Step	Action	System State	Assertion	Result
1	Test starts and Selenium Remote WebDriver connects to Docker Selenium Grid at http://localhost:4444/wd/hub	Selenium Grid is running in Docker, ready to provide browser session	-	PASS
2	Browser session opens and navigates to 'https://example.com'	Browser window shows the example.com homepage	-	PASS
3	Waits up to 10 seconds for button with id 'start-btn' to appear	Button with id 'start-btn' is present on the page	Element with id 'start-btn' is found	PASS
4	Clicks the button with id 'start-btn'	Page reacts to button click, navigation or content changes	-	PASS
5	Waits until page title changes to 'Started Page'	Page title is now 'Started Page'	Page title equals 'Started Page'	PASS
6	Asserts that the page title is exactly 'Started Page'	Page title matches expected value	assert driver.title == 'Started Page'	PASS
7	Test ends and browser session quits	Browser closes, Selenium Grid session ends	-	PASS

Failure Scenario

Failing Condition: Button with id 'start-btn' is not found within 10 seconds

Execution Trace Quiz - 3 Questions

What does the test do first after connecting to the Selenium Grid?

A Asserts the page title is 'Started Page'

B Navigates the browser to 'https://example.com'

C Clicks the button with id 'start-btn'

D Quits the browser session

Key Result

Always use explicit waits like WebDriverWait with expected conditions to handle dynamic page elements when testing with Selenium Grid in Docker.