Screenshot on failure in Selenium Python - Test Execution Trace

Test Overview

This test opens a webpage, tries to find a button, clicks it, and verifies the page title. If the test fails, it takes a screenshot to help diagnose the problem.

Test Code - unittest

Selenium Python

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.common.exceptions import NoSuchElementException
import unittest

class TestScreenshotOnFailure(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Chrome()
        self.driver.implicitly_wait(5)

    def test_click_button_and_check_title(self):
        driver = self.driver
        driver.get('https://example.com')
        try:
            button = driver.find_element(By.ID, 'submit-btn')
            button.click()
            self.assertEqual(driver.title, 'Expected Title')
        except Exception as e:
            driver.save_screenshot('failure_screenshot.png')
            raise e

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

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

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test starts and WebDriver Chrome browser opens	Chrome browser window is open and ready	-	PASS
2	Browser navigates to 'https://example.com'	Page 'https://example.com' is loaded in browser	-	PASS
3	Find element with ID 'submit-btn'	Button with ID 'submit-btn' is present on the page	-	PASS
4	Click the 'submit-btn' button	Button is clicked, page may change	-	PASS
5	Check if page title equals 'Expected Title'	Page title is checked	Assert page title == 'Expected Title'	PASS
6	Test ends and browser closes	Browser window is closed	-	PASS

Failure Scenario

Failing Condition: Element with ID 'submit-btn' is not found or page title is not 'Expected Title'

Execution Trace Quiz - 3 Questions

What happens if the button with ID 'submit-btn' is not found?

A The test passes without clicking the button

B The test ignores the missing button and continues

C A screenshot is taken and the test fails with NoSuchElementException

D The browser closes immediately without error

Key Result

Taking a screenshot immediately when a test fails helps quickly understand what the browser showed at failure time, making debugging easier.