Page Object Model in Cypress - Build an Automation Script

Login functionality using Page Object Model

Preconditions (2)

Step 1: Open the login page URL

Step 2: Enter 'testuser' in the username input field

Step 3: Enter 'Test@1234' in the password input field

Step 4: Click the login button

Step 5: Verify that the URL changes to 'https://example.com/dashboard'

Step 6: Verify that the dashboard heading 'Welcome, testuser!' is visible

✅ Expected Result: User is successfully logged in and redirected to the dashboard page with a welcome message.

Automation Requirements - Cypress

Assertions Needed:

URL should be 'https://example.com/dashboard' after login

Dashboard heading 'Welcome, testuser!' should be visible

Best Practices:

Use Page Object Model to separate page selectors and actions

Use Cypress commands and assertions consistently

Avoid hardcoded waits; use Cypress automatic waits

Use clear and descriptive method names in page objects

Automated Solution

Cypress

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

// cypress/support/pageObjects/LoginPage.js
class LoginPage {
  visit() {
    cy.visit('https://example.com/login');
  }

  fillUsername(username) {
    cy.get('#username').clear().type(username);
  }

  fillPassword(password) {
    cy.get('#password').clear().type(password);
  }

  clickLogin() {
    cy.get('button[type="submit"]').click();
  }
}

export default LoginPage;


// cypress/integration/login_spec.js
import LoginPage from '../support/pageObjects/LoginPage';

describe('Login Test using Page Object Model', () => {
  const loginPage = new LoginPage();

  it('should login successfully with valid credentials', () => {
    loginPage.visit();
    loginPage.fillUsername('testuser');
    loginPage.fillPassword('Test@1234');
    loginPage.clickLogin();

    cy.url().should('eq', 'https://example.com/dashboard');
    cy.contains('h1', 'Welcome, testuser!').should('be.visible');
  });
});

The LoginPage class encapsulates all selectors and actions related to the login page. This keeps test code clean and easy to maintain.

The visit() method opens the login page URL. The fillUsername() and fillPassword() methods enter the credentials into the input fields. The clickLogin() method clicks the login button.

In the test file, we create an instance of LoginPage and call these methods in order. After clicking login, we assert that the URL is the dashboard URL and that the welcome heading is visible.

This structure follows the Page Object Model pattern, making tests easier to read and maintain.

Common Mistakes - 3 Pitfalls

Using selectors directly inside the test instead of page objects

Using hardcoded waits like cy.wait(5000)

Not clearing input fields before typing

Bonus Challenge

Now add data-driven testing with 3 different sets of username and password inputs using the Page Object Model.

Show Hint

Practice

1. What is the main purpose of using the Page Object Model in Cypress testing?

easy

A. To write tests without any assertions

B. To avoid using selectors in tests

C. To speed up the browser loading time

D. To organize page interactions into reusable classes

Solution

1. Step 1: Understand the role of Page Object Model

   The Page Object Model (POM) organizes web page elements and actions into classes to reuse code easily.

2. Step 2: Identify the main benefit in Cypress tests

   Using POM makes tests easier to write, read, and maintain by grouping page logic separately from test logic.

3. Final Answer:

   To organize page interactions into reusable classes -> Option D

4. Quick Check:

   Page Object Model = reusable page classes [OK]

Hint: POM groups page actions into classes for reuse [OK]

Common Mistakes:

• Thinking POM speeds up browser loading
• Believing POM removes need for assertions
• Assuming POM avoids selectors entirely

2. Which of the following is the correct way to define a method inside a Cypress Page Object class to click a button with selector button.submit?

easy

A. clickSubmit() { cy.get('button.submit').click(); }

B. clickSubmit() => { cy.get('button.submit').click(); }

C. function clickSubmit() { cy.get('button.submit').click(); }

D. clickSubmit: function() { cy.get('button.submit').click(); }

Solution

1. Step 1: Recognize class method syntax in JavaScript

   Inside a class, methods are defined as methodName() { ... } without the function keyword or arrow syntax.

2. Step 2: Match the correct syntax for Cypress command

   The method should call cy.get('button.submit').click(); inside the method body.

3. Final Answer:

   clickSubmit() { cy.get('button.submit').click(); } -> Option A

4. Quick Check:

   Class method syntax = clickSubmit() { cy.get('button.submit').click(); } [OK]

Hint: Class methods use name() { } syntax, no function keyword [OK]

Common Mistakes:

• Using arrow functions inside class methods incorrectly
• Adding 'function' keyword inside class method
• Using object literal syntax inside class

3. Given this Page Object class snippet:

class LoginPage {
  visit() {
    cy.visit('/login')
  }
  enterUsername(name) {
    cy.get('#username').type(name)
  }
  enterPassword(pass) {
    cy.get('#password').type(pass)
  }
  submit() {
    cy.get('button[type=submit]').click()
  }
}

What will happen when the test calls:
const page = new LoginPage(); page.visit(); page.enterUsername('user1'); page.enterPassword('pass1'); page.submit();

medium

A. The login page loads, username and password are typed, and submit button is clicked

B. Only the login page loads, but no typing or clicking happens

C. Syntax error because methods are not async

D. The test fails because selectors are incorrect

Solution

1. Step 1: Analyze method calls in sequence

   The test creates a LoginPage object and calls methods to visit the page, type username and password, then click submit.

2. Step 2: Confirm Cypress commands are correct

   Selectors like #username, #password, and button[type=submit] are valid and commands are chained properly.

3. Final Answer:

   The login page loads, username and password are typed, and submit button is clicked -> Option A

4. Quick Check:

   Method calls execute Cypress commands in order [OK]

Hint: Methods run Cypress commands sequentially as called [OK]

Common Mistakes:

• Thinking Cypress commands need async/await
• Assuming selectors are invalid without checking
• Believing only visit() runs without chaining

4. You have this Page Object method:

login(username, password) {
  cy.get('#user').type(username)
  cy.get('#pass').type(password)
  cy.get('button.login').click()
}

But your test calls cy.visit('/login') before login(), yet fails because the username input is not found. What is the likely problem?

medium

A. The click() command must come before typing

B. The selector #user is incorrect or outdated

C. The method should use cy.find() instead of cy.get()

D. You forgot to call cy.visit() before login

Solution

1. Step 1: Identify cause of element not found error

   If the username input is not found, the selector #user might be wrong or changed on the page.

2. Step 2: Evaluate other options

   While missing cy.visit() can cause failure, the question states the failure is specifically about the username input not found, pointing to selector issue.

3. Final Answer:

   The selector #user is incorrect or outdated -> Option B

4. Quick Check:

   Element not found = wrong selector [OK]

Hint: Element not found usually means wrong selector [OK]

Common Mistakes:

• Assuming cy.find() fixes selector issues
• Thinking click() must come before typing
• Ignoring the need to visit page first

5. You want to create a Page Object for a form with multiple input fields and a submit button. Which approach best follows Cypress Page Object Model best practices?

hard

A. Use global variables for selectors and call Cypress commands directly in tests

B. Write all test steps directly inside the test without any class or methods

C. Create a class with methods for each field interaction and a submit method, using clear selectors

D. Create one method that types all fields and clicks submit without separate methods

Solution

1. Step 1: Understand POM best practices

   Best practice is to create a class that groups page elements and actions into clear, reusable methods with good selectors.

2. Step 2: Compare options

   Writing all steps in tests or using global variables reduces reusability and clarity. One big method reduces flexibility and readability.

3. Final Answer:

   Create a class with methods for each field interaction and a submit method, using clear selectors -> Option C

4. Quick Check:

   Clear methods + selectors = POM best practice [OK]

Hint: Use classes with clear methods for each page action [OK]

Common Mistakes:

• Putting all steps directly in tests
• Using global selectors without encapsulation
• Combining all actions into one big method