Zepto Playwright Testing Interview Questions & Answers

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.

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

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

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

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.

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

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

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.

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

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

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

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

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

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

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

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

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.

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

setInputFiles on the input for uploads; for downloads wait on page.waitForEvent('download') and save or inspect the file.

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

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.

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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

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

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

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

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

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.

Log in once in a setup project, save storageState to a file and reuse it in other projects or tests.

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

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.

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.

Read the next page link or IDs from earlier responses, loop until done and assert counts and uniqueness; pass IDs between calls in the same test.

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

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

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

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

API testing checks services directly and is fast and stable; UI testing checks the full user experience in the browser and is slower.

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

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.

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

An object describing how to find an element, re-evaluated on every action so it always targets the current DOM.

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.

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

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

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

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

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