JavaScript executor basics in Selenium Python - Test Execution Trace

Test Overview

This test uses Selenium with Python to open a webpage and run JavaScript code inside the browser. It verifies that the JavaScript executor correctly returns the page title.

Test Code - Selenium

Selenium Python

from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.common.by import By
from selenium.webdriver.chrome.options import Options

# Setup Chrome driver
options = Options()
options.add_argument('--headless')
service = Service()
driver = webdriver.Chrome(service=service, options=options)

try:
    # Open example page
    driver.get('https://example.com')

    # Execute JavaScript to get document title
    title = driver.execute_script('return document.title;')

    # Assert the title is 'Example Domain'
    assert title == 'Example Domain', f"Title was '{title}' instead of 'Example Domain'"
finally:
    driver.quit()

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Test starts and Chrome browser is launched in headless mode	Chrome browser is open but not visible, ready to navigate	-	PASS
2	Browser navigates to 'https://example.com'	Page loads with title 'Example Domain' visible in DOM	-	PASS
3	Execute JavaScript 'return document.title;' using Selenium's execute_script method	JavaScript runs inside browser context and returns the page title string	Check that returned title equals 'Example Domain'	PASS
4	Assert that the returned title is exactly 'Example Domain'	Title string matches expected value	assert title == 'Example Domain'	PASS
5	Close the browser and end the test	Browser closed, resources released	-	PASS

Failure Scenario

Failing Condition: The JavaScript executor returns a title different from 'Example Domain' or fails to execute

Execution Trace Quiz - 3 Questions

What does the JavaScript executor return in this test?

A The URL of the page

B The page title string

C The page HTML source

D An error message

Key Result

Using JavaScript executor allows running custom scripts inside the browser, which is useful for accessing properties or performing actions not directly supported by Selenium commands.