Percy integration basics in Cypress - Build an Automation Script

Visual testing with Percy on homepage

Preconditions (3)

Step 1: Open the homepage URL 'https://example.com'

Step 2: Wait for the page to fully load

Step 3: Take a Percy snapshot named 'Homepage snapshot'

Step 4: Verify that the Percy snapshot is created and uploaded

✅ Expected Result: Percy snapshot named 'Homepage snapshot' is successfully created and uploaded for visual testing

Automation Requirements - Cypress

Assertions Needed:

Verify the page loads without errors

Verify Percy snapshot command is called with correct name

Best Practices:

Use cy.visit() to open the page

Use cy.percySnapshot() to take visual snapshot

Use explicit waits only if necessary

Keep test steps clear and simple

Automated Solution

Cypress

/// <reference types="cypress" />

import '@percy/cypress';

describe('Percy integration basics', () => {
  it('should take a Percy snapshot of the homepage', () => {
    cy.visit('https://example.com');
    // Wait for page to load fully
    cy.get('body').should('be.visible');
    // Take Percy snapshot
    cy.percySnapshot('Homepage snapshot');
  });
});

This test script uses Cypress with Percy integration.

First, it visits the homepage URL using cy.visit().

Then, it waits for the page body to be visible to ensure the page loaded.

Finally, it calls cy.percySnapshot('Homepage snapshot') to take a visual snapshot for Percy.

This snapshot will be uploaded to Percy for visual comparison.

We import @percy/cypress to enable the cy.percySnapshot() command.

Common Mistakes - 3 Pitfalls

{'mistake': "Not importing '@percy/cypress' before using cy.percySnapshot()", 'why_bad': "The Percy commands won't be available and test will fail with an error.", 'correct_approach': "Always import '@percy/cypress' in your test file or support file."}

Taking Percy snapshot before page fully loads

{'mistake': 'Using hardcoded waits like cy.wait(5000)', 'why_bad': 'Makes tests slow and flaky if page loads faster or slower than wait time.', 'correct_approach': "Use assertions like cy.get('selector').should('be.visible') to wait dynamically."}

Bonus Challenge

Now add data-driven testing with 3 different URLs to take Percy snapshots

Show Hint

Practice

1. What is the main purpose of integrating Percy with Cypress tests?

easy

A. To speed up test execution time

B. To catch visual bugs by taking screenshots during tests

C. To generate test data automatically

D. To write unit tests for backend APIs

Solution

1. Step 1: Understand Percy's role in testing

   Percy is used to capture screenshots during tests to detect visual changes.

2. Step 2: Compare options with Percy's purpose

   Only To catch visual bugs by taking screenshots during tests matches Percy's function of catching visual bugs via screenshots.

3. Final Answer:

   To catch visual bugs by taking screenshots during tests -> Option B

4. Quick Check:

   Percy purpose = Visual bug detection [OK]

Hint: Percy = visual snapshots during tests [OK]

Common Mistakes:

• Thinking Percy speeds up tests
• Confusing Percy with test data tools
• Assuming Percy writes backend tests

2. Which of the following is the correct syntax to take a Percy snapshot in a Cypress test?

easy

A. percy.cySnapshot('Homepage')

B. cy.snapshotPercy('Homepage')

C. cy.percySnapshot('Homepage')

D. cy.takePercySnapshot('Homepage')

Solution

1. Step 1: Recall Percy snapshot command syntax

   The correct command is cy.percySnapshot('name') to capture snapshots.

2. Step 2: Match options with correct syntax

   Only cy.percySnapshot('Homepage') matches the exact syntax cy.percySnapshot('Homepage').

3. Final Answer:

   cy.percySnapshot('Homepage') -> Option C

4. Quick Check:

   Correct Percy command = cy.percySnapshot() [OK]

Hint: Look for exact cy.percySnapshot() syntax [OK]

Common Mistakes:

• Swapping method and object order
• Adding extra words like 'take'
• Using wrong method names

3. Given this Cypress test snippet with Percy integration:

describe('Visual test', () => {
  it('checks homepage', () => {
    cy.visit('/')
    cy.percySnapshot('Homepage loaded')
    cy.get('#login').click()
    cy.percySnapshot('Login clicked')
  })
})

How many Percy snapshots will be captured during this test run?

medium

A. 1

B. 3

C. 0

D. 2

Solution

1. Step 1: Count cy.percySnapshot calls in the test

   There are two calls: one after visiting homepage, one after clicking login.

2. Step 2: Confirm each call triggers a snapshot

   Each cy.percySnapshot() call captures one snapshot, so total is 2.

3. Final Answer:

   2 -> Option D

4. Quick Check:

   Number of snapshots = 2 [OK]

Hint: Count cy.percySnapshot() calls in test [OK]

Common Mistakes:

• Counting only one snapshot
• Assuming snapshots auto-capture without calls
• Confusing clicks with snapshots

4. You wrote this Cypress test with Percy snapshot:

it('checks page', () => {
  cy.visit('/page')
  cy.percySnapshot()
})

But Percy dashboard shows no snapshots. What is the likely problem?

medium

A. Missing snapshot name argument in cy.percySnapshot()

B. cy.visit() must be called after cy.percySnapshot()

C. Percy snapshots only work on mobile viewport

D. You must call cy.percySnapshot() twice per test

Solution

1. Step 1: Check cy.percySnapshot usage

   The cy.percySnapshot() command requires a name string argument to identify the snapshot.

2. Step 2: Identify missing argument issue

   Since no name is given, Percy does not capture or upload the snapshot.

3. Final Answer:

   Missing snapshot name argument in cy.percySnapshot() -> Option A

4. Quick Check:

   Snapshot name required = true [OK]

Hint: Always provide a name string to cy.percySnapshot() [OK]

Common Mistakes:

• Thinking visit order matters
• Believing Percy only works on mobile
• Assuming multiple snapshots are mandatory

5. You want to test a form with Percy snapshots at three steps: before filling, after filling, and after submission. Which code snippet correctly integrates Percy snapshots in Cypress?

hard

A. cy.visit('/form')
cy.percySnapshot('Before filling')
cy.get('#input').type('data')
cy.percySnapshot('After filling')
cy.get('#submit').click()
cy.percySnapshot('After submission')

B. cy.visit('/form')
cy.percySnapshot()
cy.get('#input').type('data')
cy.percySnapshot()
cy.get('#submit').click()
cy.percySnapshot()

C. cy.visit('/form')
cy.get('#input').type('data')
cy.percySnapshot('After filling')
cy.get('#submit').click()

D. cy.visit('/form')
cy.get('#submit').click()
cy.percySnapshot('After submission')

Solution

1. Step 1: Identify required Percy snapshots

   Snapshots needed at three steps: before filling, after filling, after submission.

2. Step 2: Check which snippet has all three snapshots with names

   Only cy.visit('/form') cy.percySnapshot('Before filling') cy.get('#input').type('data') cy.percySnapshot('After filling') cy.get('#submit').click() cy.percySnapshot('After submission') has three named cy.percySnapshot() calls at correct steps.

3. Final Answer:

   Code snippet with three named Percy snapshots at correct steps -> Option A

4. Quick Check:

   Three named snapshots = cy.visit('/form') cy.percySnapshot('Before filling') cy.get('#input').type('data') cy.percySnapshot('After filling') cy.get('#submit').click() cy.percySnapshot('After submission') [OK]

Hint: Name each snapshot and place at correct test steps [OK]

Common Mistakes:

• Omitting snapshot names
• Missing snapshots at required steps
• Calling snapshots before visit