Meta Playwright Testing Interview Questions & Answers

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.

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.

TypeScript + POM + custom fixtures, environment configs, API helpers for test data, tags like @smoke, sharding across CI machines, retries with traces, HTML/Allure reports, lint and review rules.

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

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

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.

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.

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

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.

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

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

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

npx playwright codegen records user actions and generates test code with suggested locators, handy for starting tests.

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

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

A function that remembers variables from its outer scope even after that scope has finished. They are used for private state and factory helpers.

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

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

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.

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

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.

The action runs without waiting, so the next step may run first — causing flaky failures or 'Target closed' errors. The @typescript-eslint/no-floating-promises rule catches it.

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

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

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

A Locator is lazy, re-resolved on every action and auto-waits (recommended). An ElementHandle points to one DOM node and can go stale.

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

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

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

Click to open the control, then use getByRole('option') or a text locator for the target item, instead of relying on fragile index-based selectors.

await expect.soft(locator).toHaveText('...') records the failure but lets the test continue, so you see every mismatch in one run.

Declarations of var and functions are moved to the top of their scope at compile time; let and const are hoisted but stay in the temporal dead zone until declared.

Fetch tokens in a fixture with expiry tracking and refresh it when it is about to expire, keeping tests unaware of the details.

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

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

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

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

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

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

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

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

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

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

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

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.

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.

Install the allure-playwright reporter, add it in the config reporters array and generate the report from the allure-results folder in CI.

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

const [download] = await Promise.all([ page.waitForEvent('download'), page.getByText('Export').click(), ]); await download.saveAs('reports/file.csv');

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