Playwright Testing Interview Questions for Senior Roles (₹12–15 LPA)

Strings in backticks that allow embedded expressions like `Hello ${name}` and multi-line text, useful for building dynamic locators and URLs.

await expect(page).toHaveScreenshot('home.png') compares against a baseline image; tune maxDiffPixels and mask dynamic areas like dates.

JavaScript runs one call stack and uses queues for async work; the event loop pushes callbacks from the microtask (promises) and task queues when the stack is empty.

Wait for the popup event with const [popup] = await Promise.all([page.waitForEvent('popup'), page.click('a')]), then interact with popup.

page.route('**/api/items', route => route.fulfill({ json: [...] })) intercepts and replies with test data; route.abort() simulates failures.

Send invalid payloads or missing auth and assert 400, 401 or 404 codes and the error message bodies.

Both describe the shape of data. Interfaces are extendable and suit object contracts; type aliases can also model unions and primitives.

Define projects for chromium, firefox and webkit in playwright.config.ts, set workers, then run: npx playwright test

Cover happy path, validation errors, auth and permissions, boundary values, idempotency, schema, performance and data cleanup.

Auto-waiting, a built-in test runner, Chromium/Firefox/WebKit with one API, network interception, the trace viewer and parallel runs out of the box — usually faster and less flaky.

Add retries with backoff for the API step, set a suitable timeout, and use mocks for non-critical dependencies.

Run npm init playwright@latest, which sets up config, example tests and browsers; execute with npx playwright test.

await page.route('**/api/users', route => route.fulfill({ status: 200, json: [{ id: 1, name: 'Test' }] }) );

var is function-scoped and hoisted. let and const are block-scoped; const can't be reassigned (though an object it points to can change). Prefer const, then let.

Use dotenv files per environment, read them in playwright.config and set baseURL and credentials from variables, selecting with an ENV flag.

Use the official Playwright image which contains browsers and dependencies, mount the project and run npx playwright test for consistent CI environments.

Use device descriptors such as devices['iPhone 13'] in a project config to emulate viewport, user agent and touch.

Record timestamps around the request or use response timing, then assert the duration is under an agreed threshold.

await request.post('/api/users', { data: { name: 'Asha' } }) automatically sets JSON headers and serialises the payload.

test('login', async ({ page }) => { await page.goto('/login'); await page.getByLabel('Email').fill('a@b.com'); await page.getByLabel('Password').fill('secret'); await page.getByRole('button', { name: 'Login' }).click(); await expect(page.getByRole('heading', { name: 'Dashboard' })).toBeVisible(); });

Assert the status with expect(res.status()).toBe(200), parse res.json() and check fields, using schema validation for the structure.

const [newPage] = await Promise.all([ context.waitForEvent('page'), page.getByText('Open').click(), ]); await newPage.waitForLoadState();

Use timeout and expect.timeout in config, test.setTimeout() for one test and test.slow() for known slower tests.

Set retries in the config or CLI and failed tests re-run in a fresh context, with trace recorded on first retry to diagnose flakiness.

npm is the Node package manager. package.json lists the project's dependencies and scripts, such as the command that runs the tests.

The object behind the request fixture that holds base URL, headers and cookies, and can share cookies with a browser context.

List, dot, line, HTML, JSON and JUnit reporters, plus integrations such as Allure, configurable per environment.

Register page.on('dialog', d => d.accept()) before the action triggers the dialog.

Playwright supports multiple browsers, tabs, languages and has auto-waiting and tracing; Selenium has the widest ecosystem; Cypress runs in-browser with a great UI but has more limits across tabs.

Use page.waitForResponse(res => res.url().includes('/api/orders') && res.ok()) together with the action that triggers it.

Capture the download event, save it with download.saveAs, then read the file in Node and assert on name, size or content.

Turn on trace: 'on-first-retry', open the trace viewer, check network and timing, replace hard waits with web-first assertions, isolate test data and check for sharding conflicts.

Placeholders for types that make reusable code type-safe, for example a helper function returning the same type of item that it receives.

Syntax over Promises: an async function returns a Promise and await pauses until it resolves. Every Playwright action returns a Promise, so you await each step.

Use try-catch with await, or .catch() on promises, and make sure rejected promises are never left unhandled.

In a fixture or beforeEach, call the API (request.post) to create the user or order, use it in the UI test, then delete it in teardown. It is faster and more reliable than creating data through the UI.

Create test data through API calls, verify it in the UI and clean up via API, which makes UI tests faster and more reliable.

map transforms each item, filter keeps items that match a condition, and reduce combines all items into a single value.

waitForSelector is a lower-level wait; locator assertions are preferred as they retry and are more readable.

all waits for every promise and rejects on the first failure; allSettled waits for all and reports each outcome; race settles with the first one to finish.

Use page.frameLocator('#frame').getByRole(...) so actions work inside the iframe with auto-waiting.

obj?.a?.b safely reads nested properties and returns undefined instead of throwing if something in the chain is missing.

Reusable setup/teardown units injected into tests (page, context, request). You can extend test with custom fixtures such as loggedInPage.

npx playwright test tests/login.spec.ts, add -g "test title" to match a name, or use test.only while debugging.

Use a library such as zod or ajv to define the expected schema and parse the response to fail on missing or wrongly typed fields.

Use page.route to intercept the call and fulfil it with fixed JSON so tests do not depend on external systems.

beforeEach runs the same code before every test in scope; fixtures are lazy, composable and only set up what a test uses.

Use expect(page).toHaveScreenshot() to compare with stored baselines, with thresholds and masks for dynamic regions.

Separate tests, page objects, fixtures, utilities, test data and config; use tags, projects, shared auth setup, linting, code review and a CI pipeline with sharding and reports.

User-facing ones: getByRole, getByText, getByLabel, getByPlaceholder and getByTestId, which are more resilient than CSS or XPath.

A browser is the engine instance; a context is an isolated session (cookies, storage); a page is a tab inside a context.

Fixtures set up and tear down test dependencies. Extend with test.extend({ loggedInPage: async ({ page }, use) => { ...; await use(page); } }).

Files run in parallel by default; set workers in the config and use test.describe.configure({ mode: 'parallel' }) for tests inside a file.

Named configurations that run the same tests across different browsers, devices or environments.

Log in once in global setup, save storageState to a JSON file and set use.storageState in the config so every test starts logged in.

A short function syntax that does not have its own this and arguments, taking them from the surrounding scope.

Scripts that run once before or after the whole run, for seeding data, starting services or creating authentication state.

A class receives page in its constructor, stores locators as properties and exposes actions like login(user, pass). Tests call page objects, not raw locators.

Tag tests (in the title or with { tag: '@smoke' }) and run: npx playwright test --grep @smoke (use --grep-invert to exclude).

Destructuring pulls values from arrays or objects into variables; spread expands an array or object into another, useful for copying and merging config.

Define an interface for the payload, cast or validate the parsed JSON to it (for example with zod), and use that type in assertions to catch shape changes.

Synchronous code runs line by line and blocks; asynchronous code starts a task and continues, handling the result later with promises or await.

test.step groups actions into named steps in reports; annotations such as test.skip, test.fixme and test.slow communicate intent and adjust behaviour.

An open-source end-to-end testing framework from Microsoft that automates Chromium, Firefox and WebKit through one API, in multiple languages.

Add tags in the title (@smoke) or use the tag option, and run with --grep @smoke or --grep-invert.

Set extraHTTPHeaders in the config or pass headers per request, for example Authorization: Bearer token fetched in a setup step.

Set them in the context options (geolocation, permissions, timezoneId, locale) to simulate users from other regions.

A type alias describes a shape or union of values; an enum creates a named set of constants that exists at runtime.