Cypress Testing Top 30 Interview Questions Answers

Learn and master Cypress Testing with Top 30 Interview Questions and Answers often asked in technical interviews.

1. What is Cypress and what are its key features?

Cypress is a JavaScript-based end-to-end testing framework that allows you to write fast, reliable, and easy-to-understand tests for web applications.

Its key features include a powerful API for interacting with elements, automatic waiting and retrying, time-travel debugging, and the ability to see test execution in real-time.

2. How does Cypress differ from other testing frameworks like Selenium?

Cypress differs from Selenium in several ways:

• Cypress runs directly in the browser, while Selenium relies on WebDriver to communicate with the browser.
• Cypress offers real-time reloading and automatic waiting, eliminating the need for explicit waits and sleeps.
• Cypress has a more expressive and powerful API for interacting with elements, making test code more readable and maintainable.
• Cypress provides built-in support for network stubbing and mocking, allowing easy testing of different server responses.

3. Explain the architecture of Cypress.

Cypress follows a unique architecture that sets it apart from other testing frameworks. It consists of two main components:

• Cypress Test Runner: It is an Electron-based desktop application that provides an interactive test execution environment. It allows you to see the application being tested and the test results in real-time. You can also use the Test Runner to debug and inspect your tests.
• Cypress Automation: It runs alongside the application being tested in the browser. It executes commands and assertions, controls the test flow, and communicates with the Test Runner.

4. How does Cypress handle asynchronous operations in tests?

Cypress automatically waits for commands and assertions to resolve before moving on to the next step.

It intelligently waits for the DOM to stabilize, network requests to complete, and any asynchronous operations to finish.

Cypress uses a concept called “Command Chaining” to ensure synchronous execution of commands.

For example, consider the following code snippet:

cy.get('#myButton').click().should('have.class', 'active');

In this case, Cypress will wait for the get command to find the element, then click on it, and finally assert that it has the class “active”. Cypress will automatically handle the timing and waiting for each step.

5. What are the different types of assertions available in Cypress?

Cypress provides several types of assertions to verify the expected state of elements and values. Some commonly used assertions include:

• should('exist'): Verifies that an element exists in the DOM.
• should('be.visible'): Checks if an element is visible.
• should('have.text', 'expectedText'): Compares the text content of an element with the expected value.
• should('have.attr', 'attribute', 'expectedValue'): Checks the value of a specific attribute of an element.
• should('have.class', 'className'): Verifies if an element has a particular CSS class.

6. How can you interact with elements using Cypress?

Cypress provides a rich set of commands to interact with elements. Some commonly used commands are:

• cy.get(selector): Finds an element(s) matching the selector.
• cy.contains(text): Finds an element containing the specified text.
• cy.click(): Clicks on an element.
• cy.type(text): Types text into an input field.
• cy.clear(): Clears the value of an input field.
• cy.select(value): Selects an option from a dropdown.
• cy.check(): Checks a checkbox or a radio button.
• cy.invoke('attr', 'attribute'): Retrieves the value of a specific attribute.

For example, to interact with an input field and submit a form, you can use the following code snippet:

cy.get('#username').type('john_doe');
cy.get('#password').type('password123');
cy.get('form').submit();

7. How can you handle assertions for asynchronous operations using Cypress?

Cypress automatically handles assertions for asynchronous operations.

When working with asynchronous tasks like API calls, you can use Cypress’s built-in command cy.intercept() to stub network requests and control their responses.

By using assertions within the cy.intercept() callback, you can ensure that the expected response is received.

Here’s an example of stubbing an API call and asserting the response:

cy.intercept('GET', '/api/user', { fixture: 'user.json' }).as('getUser');
cy.visit('/dashboard');
cy.wait('@getUser').then((interception) => {
  expect(interception.response.body.username).to.equal('john_doe');
});

In this case, the cy.intercept() stubs a GET request to ‘/api/user’ and responds with the contents of the ‘user.json’ fixture. The cy.wait('@getUser') waits for the stubbed request to complete, and then the assertion is made on the response body.

8. How can you perform assertions on the response of an API call using Cypress?

Cypress allows you to make assertions on the response of an API call using the .its() command.

It allows you to access properties of the response object and make assertions on them.

Here’s an example:

cy.request('GET', '/api/user').its('status').should('equal', 200);

In this case, the cy.request() makes a GET request to ‘/api/user’, and then the .its('status') accesses the ‘status’ property of the response. Finally, the .should('equal', 200) asserts that the status is equal to 200.

9. How can you work with iframes in Cypress?

To interact with elements inside an iframe, Cypress provides the .iframe() command.

You can use it to target the iframe and perform actions or assertions within its context.

Here’s an example of interacting with an element inside an iframe:

cy.iframe('#myIframe').find('.inner-element').click();

In this example, the .iframe('#myIframe') command selects the iframe with the given selector, and then the .find('.inner-element') command finds an element inside the iframe with the class ‘inner-element’. Finally, the .click() command performs a click action on that element.

10. How can you perform keyboard actions, such as pressing keys, in Cypress?

Cypress allows you to simulate keyboard actions using the .type() command.

You can pass special key aliases like ‘{enter}’, ‘{tab}’, ‘{esc}’, etc., to perform specific keyboard actions.

Here’s an example of pressing the Enter key:

cy.get('input').type('{enter}');

In this case, the .type('{enter}') command simulates pressing the Enter key on the selected input element.

11. How can you perform drag and drop actions in Cypress?

Cypress provides the .drag() command to perform drag and drop actions.

You can use it to select an element and drop it onto another element.

Here’s an example:

cy.get('.draggable').drag('.droppable');

In this example, the .get('.draggable') command selects the draggable element, and the .drag('.droppable') command drags it onto the droppable element.

12. How can you handle authentication in Cypress?

Cypress provides the .visit() command to navigate to a specific URL.

You can pass authentication credentials as options to this command to handle authentication.

Here’s an example:

cy.visit('/dashboard', {
  auth: {
  username: 'john_doe',
  password: 'password123',
  },
});

In this case, the .visit('/dashboard') command navigates to the ‘/dashboard’ URL and passes the authentication credentials for username and password.

13. How can you generate dynamic test data in Cypress?

Cypress allows you to generate dynamic test data using JavaScript functions within your test code.

You can generate random data using libraries like Faker.js or write custom functions to generate data based on specific requirements.

Here’s an example using Faker.js:

const faker = require(‘faker’);

const randomUsername = faker.internet.userName();
cy.get('#username').type(randomUsername);

In this example, the faker.internet.userName() function generates a random username, which is then typed into the ‘#username’ input field.

14. How can you take screenshots and videos during test execution in Cypress?

Cypress provides built-in commands to capture screenshots and videos during test execution.

The .screenshot() command captures a screenshot, while the .record() command starts recording a video.

Here’s an example:

cy.screenshot('myScreenshot');
cy.record();

In this case, the .screenshot('myScreenshot') command captures a screenshot and saves it with the given filename. The .record() command starts recording a video of the test execution.

15. How can you configure Cypress to run tests in different browsers?

Cypress allows you to configure and run tests in different browsers using its plugins.

You can install plugins like cypress-browserify-preprocessor or cypress-multi-reporters to enable cross-browser testing and generate multiple reports.

To configure browsers, you can modify the browsers property in the cypress.json file:

{
   "browsers": {
   "chrome": true,
   "firefox": true
  }
}

In this example, tests will run in both Chrome and Firefox.

16. How can you run Cypress tests in headless mode?

Cypress supports running tests in headless mode, which means the tests will execute without launching the Test Runner UI. To run tests in headless mode, you can use the cypress run command.

For example:

npx cypress run

This command will execute the tests in headless mode and generate the test results.

17. How can you perform parallel testing with Cypress?

Cypress allows you to perform parallel testing using third-party services like Cypress Dashboard, CircleCI, or Jenkins. These services can distribute the tests across multiple machines, speeding up the test execution process.

To set up parallel testing, you can configure your Cypress integration with the chosen service and follow their guidelines for parallel execution.

18. How can you handle test fixtures and test data in Cypress?

Cypress allows you to use test fixtures to load and manage test data. Test fixtures are JSON files that contain data used for testing, such as mock responses or sample input.

To use a fixture, you can pass its filename to commands like .visit() or .intercept().

Here’s an example:

cy.intercept('GET', '/api/user', { fixture: 'user.json' });

In this case, the fixture ‘user.json’ will be used as the response for the GET request to ‘/api/user’.

19. How can you retry failed assertions in Cypress?

Cypress automatically retries assertions by default. If an assertion fails, Cypress will automatically retry it until it passes or reaches the configured timeout.

You can customize the retry behavior by modifying the defaultCommandRetryOptions in your cypress.json file:

{
  "defaultCommandRetryOptions": {
    "interval": 1000,
    "timeout": 5000,
    "retries": 3,
    "customTimers": {
      "customRetryTimeout": 10000
    }
  }
}

In this example, the assertion will be retried three times with a one-second interval and a five-second timeout.

20. How can you skip or exclude certain tests in Cypress?

Cypress allows you to skip or exclude specific tests or test suites using the .skip() or .only() functions.

The .skip() function skips a test or suite, while the .only() function executes only the specified test or suite.

Here’s an example:

describe('My Test Suite', () => {
  it('Test 1', () => {
    // This test will be executed
  });

  it.skip('Test 2', () => {
    // This test will be skipped
  });

  it.only('Test 3', () => {
    // Only this test will be executed
  });
});

In this case, ‘Test 2’ will be skipped, ‘Test 1’ will be executed, and ‘Test 3’ will be the only test executed.

21. How can you dynamically wait for an element to appear in Cypress?

Cypress provides the .wait() command to dynamically wait for an element to appear or fulfill a specific condition. You can pass a selector or a callback function to the .wait() command.

Here’s an example:

cy.wait('@getUser').its('response.body.username').should('equal', 'john_doe');

In this example, the .wait('@getUser') command waits for the request with the alias ‘getUser’ to complete. Then, it accesses the username from the response body and asserts its value.

22. How can you access and manipulate browser cookies in Cypress?

Cypress provides the .getCookie() and .setCookie() commands to access and manipulate browser cookies.

Here’s an example:

cy.setCookie('session', 'abc123');
cy.getCookie('session').should('have.property', 'value', 'abc123');

In this case, the .setCookie('session', 'abc123') command sets a cookie named ‘session’ with the value ‘abc123’. Then, the .getCookie('session') command retrieves the cookie and asserts its value.

23. How can you perform time-travel debugging in Cypress?

Cypress allows time-travel debugging, which means you can pause and inspect the application’s state at any point during the test execution.

You can use the .debug() command to pause the test and open the DevTools to inspect the DOM, console logs, network requests, etc.

Here’s an example:

cy.get('#myButton').click().debug();

In this case, the .debug() command pauses the test after clicking the ‘#myButton’ element and opens the DevTools for debugging.

24. How can you configure Cypress to use a custom assertion library?

Cypress uses Chai as its default assertion library, but you can configure it to use a custom assertion library of your choice.

To configure a custom assertion library, you need to install the library and add the necessary configuration in your test code or support file.

Here’s an example using the Should.js assertion library:

1. Install Should.js:

2. Configure Cypress in your support file (cypress/support/index.js):

import 'should';

Now, you can use Should.js assertions in your tests.

25. How can you configure Cypress to generate test reports?

Cypress allows you to generate test reports using various plugins. One popular plugin is mochawesome, which generates HTML reports.

To configure mochawesome, you need to install the plugin and add the necessary configuration in your test code or configuration file.

Here’s an example:

1. Install mochawesome:

npm install --save-dev mochawesome

2. Configure Cypress in your configuration file (cypress.json):

{
  "reporter": "mochawesome",
  "reporterOptions": {
    "reportDir": "cypress/reports",
    "overwrite": false,
    "html": false,
    "json": true
  }
}

This configuration will generate JSON reports in the specified directory (cypress/reports).

26. How can you configure Cypress to run tests in a specific order?

By default, Cypress runs tests in an arbitrary order to ensure test independence.

However, in some cases, you may need to run tests in a specific order.

To achieve this, you can use test hooks like before, beforeEach, after, and afterEach to control the test execution flow.

Here’s an example:

describe('My Test Suite', () => {
  before(() => {
    // Runs once before all tests
  });

  beforeEach(() => {
    // Runs before each test
  });

  it('Test 1', () => {
    // Test 1
  });

  it('Test 2', () => {
    // Test 2
  });

  afterEach(() => {
    // Runs after each test
  });

  after(() => {
    // Runs once after all tests
  });
});

In this case, the before hook runs once before all tests, the beforeEach hook runs before each test, the afterEach hook runs after each test, and the after hook runs once after all tests.

27. How can you generate code coverage reports for Cypress tests?

Cypress allows you to generate code coverage reports using plugins like @cypress/code-coverage.

This plugin integrates with Istanbul to collect coverage information during test execution.

To configure code coverage reports, you need to install the plugin, add the necessary configuration, and modify your test scripts.

Here’s an example:

1. Install @cypress/code-coverage:

npm install --save-dev @cypress/code-coverage

2. Configure Cypress in your configuration file (cypress.json):

{
  "pluginsFile": "cypress/plugins/index.js"
}

3. Create the plugins file (cypress/plugins/index.js):

const { register } = require('@cypress/code-coverage/task');

module.exports = (on, config) => {
  register(on, config);
  return config;
};

4. Modify your test scripts in package.json:

{
  "scripts": {
    "test": "cypress run --env coverage=true"
  }
}

Now, when you run npm run test, code coverage reports will be generated in the coverage directory.

28. How can you configure Cypress to run tests in different environments or configurations?

Cypress allows you to configure different environments or configurations using environment variables. You can set environment variables in your test scripts or use a configuration file to define different sets of variables.

Here’s an example using environment variables:

1. Define environment variables:

export CYPRESS_BASE_URL=http://localhost:3000
export CYPRESS_API_URL=http://localhost:4000/api

2. Access environment variables in your test code:

const baseUrl = Cypress.env('BASE_URL');
const apiUrl = Cypress.env('API_URL');

In this case, the CYPRESS_BASE_URL and CYPRESS_API_URL environment variables are accessed using Cypress.env().

29. How can you handle file uploads in Cypress?

Cypress provides the .attachFile() command to handle file uploads. You can use it to select and upload files from your local machine.

Here’s an example:

cy.get('input[type="file"]').attachFile('path/to/file.png');

In this example, the .attachFile() command attaches the file located at 'path/to/file.png' to the input field of type ‘file’.

30. How can you configure Cypress to run tests in a CI/CD pipeline?

To run Cypress tests in a CI/CD pipeline, you need to configure your pipeline to install the necessary dependencies, run the test command, and generate the test reports.

Here’s an example using a typical Jenkins pipeline:

pipeline {
  agent any

  stages {
    stage('Build') {
      steps {
        // Install dependencies
        sh 'npm install'
      }
    }

    stage('Test') {
      steps {
        // Run tests
        sh 'npm run test'
      }
    }

    stage('Publish Reports') {
      steps {
        // Publish test reports
        publishHTML(target: [
          allowMissing: false,
          alwaysLinkToLastBuild: true,
          keepAll: true,
          reportDir: 'cypress/reports',
          reportFiles: 'mochawesome.html',
          reportName: 'Cypress Test Report'
        ])
      }
    }
  }
}

In this example, the pipeline installs dependencies, runs tests using the npm run test command, and publishes the test reports using the Jenkins HTML Publisher plugin.