Salesforce Playwright Testing Interview Questions & Answers

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

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

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

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

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

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.

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(); });

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

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

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

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

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

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

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

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

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.

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

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.

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

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

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

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.

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

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

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.

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

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.

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

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

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

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

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

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

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

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.

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

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.

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

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

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

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.

locator.hover() and locator.dragTo(target) perform these actions, with auto-waiting for actionability.

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.

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.

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

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

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

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

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.

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

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

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

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

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

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

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.

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.

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

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

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

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

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

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.

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

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.

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.

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.

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.

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

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.

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

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.

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

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

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