Playwright Interview Questions

Playwright interview questions#

Playwright interviews focus on locators, auto-waiting, isolation, fixtures and debugging failures in CI.

1. What is Playwright and which browsers does it support?#

An open-source testing and automation framework from Microsoft. One API drives Chromium (Chrome, Edge), Firefox and WebKit (Safari), with bindings for TypeScript/JavaScript, Python, Java and .NET.

2. What is auto-waiting?#

Before an action, Playwright waits for the element to be attached, visible, stable, able to receive events and enabled. Tests don't need manual waits or sleeps.

3. What are web-first assertions?#

Assertions on locators — await expect(locator).toBeVisible(), toHaveText(), toHaveCount() — that retry until they pass or time out. Non-retrying checks on a value read once are a common cause of flakiness.

4. Which locators does Playwright recommend?#

User-facing locators: getByRole first, then getByLabel, getByPlaceholder, getByText and getByTestId. CSS/XPath only when necessary.

5. What does "strict mode" mean for locators?#

An action on a locator matching more than one element throws an error instead of picking one, forcing you to write unambiguous locators.

6. What is a browser context?#

An isolated, incognito-like browser session with its own cookies and storage. Playwright creates a new context for every test, which is fast and keeps tests independent.

7. What are fixtures?#

Values a test requests by name — page, context, request — created before and torn down after the test. Custom fixtures (test.extend) provide ready-made page objects, logged-in pages or seeded data.

8. How do you avoid logging in before every test?#

Log in once in a setup project, save storageState (cookies and local storage) to a file, and configure projects to load it.

9. How do you test APIs with Playwright?#

With the request fixture (or request.newContext()): request.get/post/put/delete, then assert on status(), headers() and json().

10. How do you mock network requests?#

page.route(url, handler) — route.fulfill() to return a fake response, route.fetch() + fulfill to modify the real one, route.abort() to block it. Register routes before navigation.

11. What is the Trace Viewer?#

A recording of a test run — actions, DOM snapshots, network, console and source. Configure trace: 'on-first-retry' and open trace.zip with npx playwright show-trace or trace.playwright.dev to debug CI failures.

12. How does Playwright run tests in parallel?#

Test files are distributed across worker processes (workers setting); fullyParallel: true also parallelises tests within a file. --shard=1/4 splits a suite across machines.

13. What are projects in the config?#

Named configurations — usually browsers or devices — that run the same tests with different settings, such as Desktop Chrome, Firefox, WebKit and iPhone.

14. How do you handle a new tab or popup?#

Wait for the event while triggering it: const popupPromise = page.waitForEvent('popup'); await page.getByText('Open').click(); const popup = await popupPromise; then work with popup like any page.

15. How do you handle file uploads and downloads?#

Uploads: await page.getByLabel('Upload').setInputFiles('report.pdf'). Downloads: const download = page.waitForEvent('download'); await click; (await download).saveAs(path).

16. What is codegen?#

npx playwright codegen <url> records your actions and generates test code with recommended locators — good for learning and scaffolding, then refined by hand.

17. How do you mark tests as flaky or skip them?#

Playwright reports tests that fail then pass on retry as "flaky". Use test.skip(), test.fixme() and test.fail() with a linked ticket while fixing root causes.

18. Playwright vs Cypress vs Selenium?#

Playwright: all engines including WebKit, multi-tab/origin, multiple languages, parallel and tracing built in. Cypress: in-browser JavaScript runner with excellent interactive debugging. Selenium: the W3C standard with the broadest language and browser support but more setup.