Mastercard Playwright Testing Interview Questions & Answers

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

Run in parallel with sharding, reuse authentication state, set up data through APIs, avoid unnecessary waits, run smoke on every commit and the full suite nightly.

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 environment variables or .env files, a baseURL in config, API calls for setup and cleanup, and unique data per run.

Use request.post with multipart: { file: { name, mimeType, buffer } } and assert the response and stored file details.

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

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.

page.screenshot() for captures and config options use: { screenshot: 'only-on-failure', video: 'retain-on-failure' } for automatic evidence.

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

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

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

Log in with request.post, call request.storageState(), and create a browser context using that state.

string, number, boolean, null, undefined, symbol, bigint and object (including arrays and functions).

It records screenshots, DOM snapshots, network calls and actions per step so you can replay a failed run and see exactly what happened.

Functions that take other functions as arguments or return them, such as map, filter and reduce, or a helper that wraps retry logic around a test step.

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

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

click simulates a real user click with actionability checks; dispatchEvent fires a DOM event directly without those checks.

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

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

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

POST the query and variables as JSON to the single endpoint and assert both data and errors fields in the response.

Integrate axe-core through @axe-core/playwright, run an analysis on the page and assert that there are no violations.

Playwright locators pierce open shadow roots by default, so getByRole and CSS locators work without special handling.

Use --debug or the Inspector, page.pause(), UI mode, the trace viewer and headed runs with slowMo.

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

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

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.

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

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

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

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(); });

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

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

Use npx playwright test --shard=1/4 in each CI job and merge reports afterwards to reduce total run time.

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

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

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

Both describe object shapes. Interfaces can be extended and merged; type aliases can also describe unions and primitives. Use interfaces for page or test-data shapes, types for unions.

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

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

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.

Rely on auto-waiting plus a web-first assertion on the final state, disable animations in config for tests and avoid fixed timeouts.

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

Before acting, Playwright waits for the element to be attached, visible, stable, enabled and able to receive events — so manual waits are rarely needed.

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.

Create a class that takes a page, defines locators as properties and exposes action methods; instantiate it in a fixture for clean tests.

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

Assertions like expect(locator).toBeVisible() that retry until they pass or time out, unlike one-off checks.

locator.hover() and locator.dragTo(target) perform these actions, with auto-waiting for actionability.

undefined means a variable has not been assigned; null is an intentional empty value.

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

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.

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

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

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

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

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

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

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

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

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

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

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.

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.

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

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.