Uber Playwright Testing Interview Questions & Answers

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.

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

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

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

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

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

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

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

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

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

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.

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

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

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

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

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

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

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

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

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.

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.

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

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.

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.

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

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.

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

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

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.

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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.

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

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.

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

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

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.

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.

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(); });

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

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

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.

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

Workflow: checkout → setup-node → npm ci → npx playwright install --with-deps → npx playwright test → upload playwright-report as an artifact.

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.

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

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