Performance metrics collection in Selenium Python - Test Execution Trace

Test Overview

This test collects performance metrics from a web page using Selenium WebDriver in Python. It verifies that the page load time is within an acceptable limit.

Test Code - unittest

Selenium Python

from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.common.by import By
import time
import unittest

class PerformanceMetricsTest(unittest.TestCase):
    def setUp(self):
        service = Service()
        self.driver = webdriver.Chrome(service=service)
        self.driver.implicitly_wait(10)

    def test_page_load_performance(self):
        self.driver.get('https://example.com')
        navigation_start = self.driver.execute_script('return window.performance.timing.navigationStart')
        load_event_end = self.driver.execute_script('return window.performance.timing.loadEventEnd')
        load_time = load_event_end - navigation_start
        print(f'Page load time: {load_time} ms')
        self.assertLess(load_time, 5000, f'Page load time is too high: {load_time} ms')

    def tearDown(self):
        self.driver.quit()

if __name__ == '__main__':
    unittest.main()

Execution Trace - 7 Steps

Step	Action	System State	Assertion	Result
1	Test starts and Chrome browser opens	Chrome browser window is open and ready	-	PASS
2	Navigates to 'https://example.com'	Browser loads the example.com homepage	-	PASS
3	Executes JavaScript to get navigationStart timestamp	Retrieves navigation start time from browser performance timing API	-	PASS
4	Executes JavaScript to get loadEventEnd timestamp	Retrieves page load event end time from performance timing API	-	PASS
5	Calculates page load time as loadEventEnd - navigationStart	Page load time calculated in milliseconds	-	PASS
6	Asserts that page load time is less than 5000 ms	Verifies performance metric is within acceptable limit	Assert load_time < 5000 ms	PASS
7	Closes the browser and ends the test	Browser window closed	-	PASS

Failure Scenario

Failing Condition: Page load time exceeds 5000 milliseconds

Execution Trace Quiz - 3 Questions

What does the test verify about the web page?

A The page loads within 5 seconds

B The page title is correct

C The page contains a specific button

D The page URL is redirected

Key Result

Always measure and assert performance metrics like page load time to catch slow user experiences early.