Top 40 Playwright interview questions and answers- Basic to Advance

In web development and testing, Playwright has emerged as a powerful tool for automating browsers and conducting robust, reliable tests. Unlike traditional tools like Selenium, Playwright provides multi-browser support, automatic waiting, and modern web features out of the box, making it easier to test applications across different environments. This article gives you comprehensive list of Playwright interview questions and detailed answers to help you prepare effectively.

Playwright Interview Questions with Detailed Answers
Playwright Interview Questions with Detailed Answers

Playwright Interview Questions with Detailed Answers

  1. What is Playwright?
  2. How does Playwright differ from Selenium?
  3. What are the key features of Playwright?
  4. Can you explain the architecture of Playwright?
  5. How do you install Playwright?
  6. What types of tests can you perform using Playwright?
  7. How does Playwright handle asynchronous operations?
  8. Can you describe how to handle dynamic content in Playwright?
  9. What are some common assertions used in Playwright?
  10. How do you handle file uploads in Playwright?
  11. Can you explain how to perform mobile testing using Playwright?
  12. What are some common exceptions encountered while using Playwright?
  13. How do you implement parallel testing in Playwright?
  14. Can you explain how network interception works in Playwright?
  15. How do you capture screenshots during tests in Playwright?
  16. What strategies do you use for handling iframes in Playwright?
  17. How do you set up test fixtures in Playwright?
  18. Can you describe how to manage dependencies between tests using Playwright?
  19. How do you perform data-driven testing using Playwright?
  20. What are some best practices when writing tests in Playwright?
  21. How can you run tests in headless and headed modes in Playwright?
  22. Explain how Playwright handles browser contexts and why they are useful.
  23. How do you handle authentication in Playwright for repeated tests?
  24. Can you explain how to handle multi-tab or pop-up window interactions in Playwright?
  25. How can you simulate geolocation or timezone settings in Playwright?
  26. What is the purpose of the expect library in Playwright, and how does it work?
  27. Can you describe how to handle API requests within Playwright tests?
  28. How do you handle page load performance testing in Playwright?
  29. What is auto-waiting in Playwright, and how does it affect test stability?
  30. How can you execute JavaScript within the browser using Playwright?
  31. Can you describe how to handle keyboard and mouse events in Playwright?
  32. How do you deal with browser logs and error messages in Playwright?
  33. What strategies can you use for debugging tests in Playwright?
  34. Can you explain how to mock geolocation in Playwright?
  35. How can you test for web accessibility with Playwright?
  36. What are trace files in Playwright, and how can you use them?
  37. How do you simulate network speed or offline mode in Playwright?
  38. Can you describe how to handle browser storage in Playwright?
  39. How do you integrate Playwright with CI/CD pipelines?

1. What is Playwright?

Answer:

Playwright is an open-source automation framework developed by Microsoft that allows developers to automate web applications across various browsers and platforms. It supports multiple programming languages, including JavaScript, TypeScript, Python, C#, and Java. Playwright enables end-to-end testing by simulating user interactions such as clicks, form submissions, and navigation.

Its key features include multi-browser support (Chromium, Firefox, and WebKit), automatic waiting, network interception, and the ability to capture screenshots and videos during tests. This versatility makes it a popular choice for developers looking to ensure the functionality and performance of their web applications.

2. How does Playwright differ from Selenium?

Answer: Playwright differs from Selenium in several significant ways:

  • Architecture: While Selenium uses the WebDriver protocol to communicate with browsers, which can introduce latency due to HTTP requests, Playwright communicates directly with the browser’s DevTools protocol. This results in faster execution and more reliable interactions.
  • Browser Support: Playwright supports multiple browsers out of the box (Chromium, Firefox, WebKit), whereas Selenium requires additional configuration for different browsers.
  • Automatic Waiting: Playwright has built-in mechanisms for automatic waiting for elements to be ready before performing actions. This reduces flakiness in tests compared to Selenium.
  • Modern Features: Playwright supports modern web features like Shadow DOM and WebSockets natively, allowing for more comprehensive testing of contemporary web applications.

3. What are the key features of Playwright?

Answer: Playwright offers several key features that enhance its usability and effectiveness:

  • Cross-Browser Testing: It supports testing across Chromium, Firefox, and WebKit with a single API.
  • Multi-Language Support: Playwright can be used with various programming languages such as JavaScript, Python, C#, and Java.
  • Headless Mode: Tests can run in headless mode (without a UI), which is useful for CI/CD pipelines.
  • Auto-Waiting: It automatically waits for elements to be ready before interacting with them, reducing the need for manual wait commands.
  • Network Interception: Developers can intercept network requests and responses, allowing for testing under various conditions.
  • Mobile Emulation: It provides capabilities for mobile testing by emulating devices like iPhones or Android phones.

4. Can you explain the architecture of Playwright?

Answer: Playwright’s architecture is designed to facilitate efficient browser automation. It consists of several components:

  • Browser Contexts: Each browser context is an isolated environment where tests can run independently. This allows for parallel testing without interference between tests.
  • Pages: Each context can contain multiple pages (tabs), which represent different views or states of a web application.
  • Locators: Playwright uses locators to identify elements on a page. These locators can be based on CSS selectors, text content, or other attributes.
  • API Communication: Instead of relying on WebDriver’s HTTP requests, Playwright communicates directly with the browser via the DevTools protocol. This direct communication enhances performance and reliability.

5. How do you install Playwright?

Answer: To install Playwright, follow these steps:

  1. Ensure you have Node.js installed on your machine.
  2. Open your terminal or command prompt.
  3. Run the following command to install Playwright via npm:
   npm install playwright
  1. After installation, you can also install browsers with:
   npx playwright install

This command installs the necessary browser binaries required for testing.

6. What types of tests can you perform using Playwright?

Answer: Playwright supports various types of testing:

  • End-to-End Testing: Simulates user interactions from start to finish within a web application.
  • API Testing: Allows testing of backend services by sending HTTP requests and validating responses.
  • Performance Testing: Measures load times and responsiveness of web applications.
  • Visual Regression Testing: Compares screenshots taken before and after changes to detect unintended UI changes.
  • Cross-Browser Testing: Ensures that applications work consistently across different browsers.

7. How does Playwright handle asynchronous operations?

Answer: Playwright is built on top of JavaScript’s asynchronous programming model using Promises and async/await syntax. This means that when you perform actions such as navigating to a page or clicking an element, these operations return promises that must be awaited before proceeding to the next action. For example:

const { chromium } = require('playwright');

(async () => {
    const browser = await chromium.launch();
    const page = await browser.newPage();
    await page.goto('https://example.com');
    const title = await page.title();
    console.log(title);
    await browser.close();
})();

In this example, each action waits for the previous one to complete before moving forward.

8. Can you describe how to handle dynamic content in Playwright?

Answer:

Handling dynamic content in Playwright involves waiting for elements to appear or change state before interacting with them. You can use methods like waitForSelector or waitForTimeout to manage timing issues effectively:

await page.waitForSelector('.dynamic-element', { state: 'visible' });

This line ensures that the script waits until the specified element is visible on the page before proceeding with further actions.

9. What are some common assertions used in Playwright?

Answer:

Assertions are crucial in validating test outcomes. While Playwright itself does not provide built-in assertion methods, it integrates seamlessly with popular testing frameworks like Jest or Mocha that offer assertion capabilities. Common assertions include:

  • Visibility Check:
  await expect(element).toBeVisible();
  • Text Assertion:
  await expect(element).toHaveText('Expected Text');
  • Attribute Assertion:
  await expect(element).toHaveAttribute('href', 'https://example.com');

These assertions help ensure that your application behaves as expected during tests.

10. How do you handle file uploads in Playwright?

Answer: To handle file uploads in Playwright, you can use the setInputFiles method on file input elements:

const input = await page.$('input[type="file"]');
await input.setInputFiles('/path/to/file.txt');

This code snippet selects a file input element and sets it with a specified file path, simulating a user uploading a file through the interface.

11. Can you explain how to perform mobile testing using Playwright?

Answer: Playwright provides built-in support for mobile device emulation through its devices module. You can specify a device configuration when creating a new browser context:

const { devices } = require('playwright');

const iPhone = devices['iPhone 11'];
const context = await browser.newContext(iPhone);
const page = await context.newPage();
await page.goto('https://example.com');

This code snippet sets up an emulated environment that mimics an iPhone 11’s screen size and capabilities.

12. What are some common exceptions encountered while using Playwright?

Answer: While working with Playwright, developers may encounter various exceptions such as:

  • TimeoutError: Occurs when an operation takes longer than expected.
  • ElementNotFoundError: Raised when trying to interact with an element that does not exist on the page.
  • NavigationError: Triggered when navigation fails due to network issues or invalid URLs.

Handling these exceptions gracefully in your test scripts is essential for robust automation.

13. How do you implement parallel testing in Playwright?

Answer: Parallel testing in Playwright can be achieved by launching multiple browser contexts or instances simultaneously within your test suite. You can utilize test runners like Jest or Mocha that support parallel execution natively:

const { chromium } = require('playwright');

(async () => {
    const browser = await chromium.launch();

    // Create multiple contexts
    const context1 = await browser.newContext();
    const context2 = await browser.newContext();

    // Run tests in parallel across contexts
    const page1 = await context1.newPage();
    const page2 = await context2.newPage();

    await Promise.all([
        page1.goto('https://example.com'),
        page2.goto('https://example.org')
    ]);

    await browser.close();
})();

This approach allows tests to run concurrently across different contexts or pages.

14. Can you explain how network interception works in Playwright?

Answer: Network interception allows developers to monitor and manipulate network requests made by their application during tests. You can use page.route() to intercept requests:

await page.route('**/*', (route) => {
    // Modify request if needed
    route.continue(); // Continue with the original request
});

This capability is useful for mocking responses or simulating different server conditions during testing.

15. How do you capture screenshots during tests in Playwright?

Answer: Capturing screenshots is straightforward in Playwright using the screenshot() method:

await page.screenshot({ path: 'screenshot.png' });

You can also capture full-page screenshots by setting the fullPage option:

await page.screenshot({ path: 'fullpage.png', fullPage: true });

Screenshots are valuable for visual regression testing and debugging failed test cases.

16. What strategies do you use for handling iframes in Playwright?

Answer: To interact with iframes in Playwright, you first need to get a reference to the iframe’s content frame using frameLocator() or frame() methods:

const frame = await page.frame({ name: 'iframeName' });
await frame.fill('#inputField', 'Test Input');

This approach allows you to perform actions within an iframe just like you would on a regular page.

17. How do you set up test fixtures in Playwright?

Answer: Test fixtures help manage setup and teardown processes consistently across tests. In Jest or Mocha (or similar frameworks), you can define fixtures using hooks like beforeEach or afterEach:

beforeEach(async () => {
    context = await browser.newContext();
    page = await context.newPage();
});

afterEach(async () => {
    await context.close();
});

This structure ensures that each test runs in a fresh environment without side effects from previous tests.

18. Can you describe how to manage dependencies between tests using Playwright?

Answer: Managing dependencies between tests typically involves careful design of your test suite where each test is independent whenever possible. However, if dependencies are unavoidable (e.g., setup data required by subsequent tests), consider using global variables or state management techniques:

let sharedData;

beforeAll(async () => {
    sharedData = await setupData(); // Prepare data needed by multiple tests
});

test('Test A', async () => {
    expect(await getData(sharedData)).toBe(true);
});

test('Test B', async () => {
    expect(await validateData(sharedData)).toBe(true);
});

This ensures that shared data is prepared once but used across multiple tests without redundancy.

19. How do you perform data-driven testing using Playwright?

Answer: Data-driven testing involves running the same test logic with different sets of data inputs. You can achieve this by parameterizing your tests using external data sources such as JSON files or databases:

const testData = require('./data.json');

testData.forEach(data => {
    test(`Testing ${data.input}`, async () => {
        const result = await performAction(data.input);
        expect(result).toBe(data.expectedOutput);
    });
});

By iterating over datasets, this approach enhances coverage without duplicating code.

20. What are some best practices when writing tests in Playwright?

Answer: To ensure effective automated testing with Playwright, consider these best practices:

  • Keep Tests Independent: Each test should run independently without relying on others’ state.
  • Use Descriptive Names: Name your tests clearly so their purpose is immediately understood.
  • Leverage Page Objects: Implement Page Object Model (POM) design pattern to encapsulate locators and actions related to specific pages.
  • Organize Tests Logically: Group related tests together based on functionality or feature areas.
  • Regularly Update Tests: Keep your test suite updated as application changes occur; stale tests can lead to false positives/negatives.

By following these guidelines, you’ll create robust and maintainable automated tests that effectively validate your applications’ functionality over time.

21. How can you run tests in headless and headed modes in Playwright?

Answer:

In Playwright, you can toggle between headless and headed modes by setting the headless option when launching a browser. Headless mode means the browser runs without a visible UI, which is faster and ideal for CI/CD pipelines. Headed mode is useful for debugging. For example:

const { chromium } = require('playwright');
(async () => {
    const browser = await chromium.launch({ headless: false }); // Set to true for headless mode
    const page = await browser.newPage();
    await page.goto('https://example.com');
    await browser.close();
})();

22. Explain how Playwright handles browser contexts and why they are useful.

Answer:

Playwright’s browser contexts enable isolated test sessions within the same browser instance. Each context has its cookies, cache, and storage, allowing tests to run independently and in parallel. Browser contexts are particularly useful for multi-user scenarios or when testing applications with isolated environments.

23. How do you handle authentication in Playwright for repeated tests?

Answer:

To handle authentication, you can either use stored cookies or network requests. Playwright allows saving and loading cookies and storage state, which enables you to bypass login for each test. For example:

const { chromium } = require('playwright');
(async () => {
    const browser = await chromium.launch();
    const context = await browser.newContext({ storageState: 'auth.json' });
    const page = await context.newPage();
    await page.goto('https://example.com/dashboard');
    await browser.close();
})();

Using storageState helps persist authentication between tests, speeding up execution.

24. Can you explain how to handle multi-tab or pop-up window interactions in Playwright?

Answer:

In Playwright, managing multiple tabs or pop-ups involves listening for the page event on the context. When a new tab opens, you can control it by storing the reference and switching between tabs as needed. Example:

const [popup] = await Promise.all([
    page.waitForEvent('popup'), // Listen for popup event
    page.click('a[target="_blank"]') // Action that triggers popup
]);
await popup.waitForLoadState();
await popup.goto('https://example.com');

25. How can you simulate geolocation or timezone settings in Playwright?

Answer:

Playwright allows you to set geolocation and timezone for browser contexts. This is useful for testing location-based features. For example:

const context = await browser.newContext({
    geolocation: { latitude: 37.7749, longitude: -122.4194 },
    timezoneId: 'America/Los_Angeles'
});
const page = await context.newPage();
await page.goto('https://maps.example.com');

26. What is the purpose of the expect library in Playwright, and how does it work?

Answer:

The expect library in Playwright provides assertion utilities, ensuring the tested web elements or conditions match expected values. It’s a fundamental part of Playwright’s test runner, allowing assertions like:

await expect(page).toHaveTitle('Expected Page Title');
await expect(element).toBeVisible();

The library ensures each test has the expected behavior before proceeding.

27. Can you describe how to handle API requests within Playwright tests?

Answer:

Playwright has built-in support for handling API requests with the page.request and route objects. You can intercept and mock API requests, which is useful for testing without relying on external servers. Example:

await page.route('**/api/v1/users', route => {
    route.fulfill({
        contentType: 'application/json',
        body: JSON.stringify({ id: 1, name: 'John Doe' })
    });
});

28. How do you handle page load performance testing in Playwright?

Answer:

To measure page load performance, Playwright can capture metrics such as load, DOMContentLoaded, and first contentful paint times. Using page.evaluate, you can retrieve these metrics for analysis:

const timing = await page.evaluate(() => JSON.stringify(window.performance.timing));
console.log('Page load metrics:', timing);

This enables monitoring of performance regressions.

29. What is auto-waiting in Playwright, and how does it affect test stability?

Answer:

Playwright automatically waits for elements to be ready before interacting with them, which reduces the need for explicit waits and enhances test stability. Playwright auto-waits for actions like clicks, typing, and navigating, making tests more resilient to load time fluctuations.

30. How can you execute JavaScript within the browser using Playwright?

Answer:

You can run JavaScript in the browser context using page.evaluate(). This is helpful for retrieving or modifying page data directly. Example:

const data = await page.evaluate(() => document.title);
console.log('Page title:', data);

31. Can you describe how to handle keyboard and mouse events in Playwright?

Answer:

Playwright provides page.keyboard and page.mouse for simulating keyboard and mouse events. For instance, page.keyboard.press('Enter') simulates pressing Enter, while page.mouse.click(x, y) performs a click at specific coordinates.

32. How do you deal with browser logs and error messages in Playwright?

Answer:

Playwright can capture console logs and errors by listening to the console and pageerror events. This enables you to log browser messages or errors for debugging:

page.on('console', msg => console.log(msg.text()));
page.on('pageerror', err => console.error('Page error:', err));

33. What strategies can you use for debugging tests in Playwright?

Answer:

Debugging in Playwright can be done by running tests in headed mode, using page.pause() for interactive debugging, and setting slowMo in the browser launch options to slow down operations:

const browser = await chromium.launch({ headless: false, slowMo: 100 });

This helps observe each step during test execution.

34. How can you take video recordings of test executions in Playwright?

Answer:

Playwright can record videos by enabling recordVideo in the browser context options. Videos are saved for later review:

const context = await browser.newContext({
    recordVideo: { dir: './videos/' }
});

35. Can you explain how to mock geolocation in Playwright?

Answer:

Mocking geolocation in Playwright involves setting geolocation coordinates in the browser context. This is useful for testing applications that rely on location data.

36. How can you test for web accessibility with Playwright?

Answer:

Playwright doesn’t provide built-in accessibility testing, but you can integrate third-party libraries like axe-core for accessibility checks within tests.

37. What are trace files in Playwright, and how can you use them?

Answer:

Trace files record a snapshot of each test step and its interactions, useful for post-test analysis. Enable tracing with:

await context.tracing.start({ screenshots: true, snapshots: true });
await context.tracing.stop({ path: 'trace.zip' });

38. How do you simulate network speed or offline mode in Playwright?

Answer:

To simulate network conditions, use page.emulateNetworkConditions to mimic slow or offline networks.

39. Can you describe how to handle browser storage in Playwright?

Answer:

Playwright allows you to save and load local and session storage states to maintain continuity across tests. This is particularly helpful for login persistence.

40. How do you integrate Playwright with CI/CD pipelines?

Answer:

Integrating Playwright with CI/CD involves setting up Playwright in the CI environment, configuring the necessary environment variables, and running headless tests.

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