Visual regression testing concept in Cypress - Test Execution Trace

Test Overview

This test checks if the homepage looks the same as before by taking a screenshot and comparing it to a saved image. It helps find unexpected visual changes.

Test Code - Cypress

Cypress

describe('Visual Regression Test for Homepage', () => {
  it('should match the baseline screenshot', () => {
    cy.visit('https://example.com')
    cy.get('header').should('be.visible')
    cy.matchImageSnapshot('homepage')
  })
})

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Test starts	Test runner initialized, ready to run the visual regression test	-	PASS
2	Browser opens and navigates to 'https://example.com'	Homepage loads fully with header visible	Page loaded successfully	PASS
3	Finds the header element on the page	Header element is present and visible	cy.get('header').should('be.visible') verifies header is visible	PASS
4	Takes a screenshot and compares it to the baseline image named 'homepage'	Screenshot captured and compared to saved baseline	cy.matchImageSnapshot('homepage') checks for visual differences	PASS
5	Test ends with visual comparison result	No visual differences found	Visual snapshot matches baseline	PASS

Failure Scenario

Failing Condition: The current screenshot differs from the baseline image beyond allowed threshold

Execution Trace Quiz - 3 Questions

What does the test verify with cy.matchImageSnapshot('homepage')?

A It compares the current page screenshot to a saved baseline image

B It checks if the header element is clickable

C It verifies the page URL is correct

D It tests if the page loads within 3 seconds

Key Result

Visual regression tests help catch unexpected UI changes by comparing screenshots, ensuring the app looks consistent after updates.