TypeScript Interview Questions 2026

If a team currently using Selenium plans to migrate to Playwright, how would you help them adopt the new framework? Cover project structure, locator migration, parallel execution setup, and CI integration.

Write Playwright code to handle multiple windows (browser contexts/tabs) and perform actions on a new page. Explain the difference between new page events and popup events, and how to wait for a page load before interacting.

Explain the different types of locators available in Playwright (CSS, XPath, text, role, test-id). Which are most resilient and why? Explain why role-based locators are preferred over XPath for accessibility and test stability.

Explain the debug process in Playwright. Cover Playwright Inspector (PWDEBUG=1), trace viewer (playwright show-trace), headed mode, slow-motion, and how to capture video/screenshots on test failure for CI debugging.

Explain the difference between PUT and PATCH in REST APIs. When is each appropriate? Show how you would test both verbs using Playwright's APIRequestContext, and explain how to validate partial vs full resource updates.

Explain the filter(), map(), and reduce() array methods in JavaScript with examples. Show how you would use them together to process a list of test results: filtering failures, mapping to error messages, and reducing to a summary count.

Explain the difference between Playwright's page.fill(), page.type(), and page.locator().pressSequentially(). When would you use each? How does Playwright handle Angular or React forms that rely on input events?

Explain async/await in JavaScript. How does it differ from Promise chaining? Write a function that fetches data from three APIs in parallel (Promise.all) and one after another (sequential await). When would you choose each?

What is cross-browser testing? How do you run the same Playwright test suite on Chrome, Firefox, and WebKit simultaneously? How do you handle browser-specific issues in your automation code?

Explain the difference between a TypeScript interface and a type alias. Give a concrete case where only one of them can express what you need.