Bloomberg Playwright Testing Interview Questions & Answers

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

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

TypeScript adds static types on top of JavaScript and compiles to it. Types catch errors early and give better autocomplete, which helps in larger test suites.

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

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

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.

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.

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

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.

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

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

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

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.

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

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

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.

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.

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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

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.

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

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

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.

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

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.

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

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

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

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

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

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.

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

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

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

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

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

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.

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