Oracle Playwright Testing Interview Questions & Answers

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

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.

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

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.

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

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

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

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

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

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.

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

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.

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

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

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

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

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.

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

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.

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

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

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

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

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.

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

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

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

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.

Use the request fixture: const res = await request.get('/api/users'); expect(res.ok()).toBeTruthy(); const body = await res.json();

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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(); });

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

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

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

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

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

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

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.

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.

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.

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.

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.

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

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.

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

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.

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

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

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

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