React Testing and Debugging

Question 1

What is React Testing Library?

Accepted Answer

A testing utility that encourages testing components the way users interact with them, focusing on behavior over implementation

Answer

React Testing Library encourages tests that mirror user behavior, using queries like getByText and getByRole rather than testing internal component details.

Question 2

What is Jest?

Accepted Answer

A JavaScript testing framework commonly used with React that provides assertions, mocking, and code coverage

Answer

Jest is the default testing framework for React projects, offering zero-config setup, snapshot testing, mocking capabilities, and built-in code coverage.

Question 3

What are React DevTools?

Accepted Answer

A browser extension that lets you inspect React component hierarchy, props, state, and performance

Answer

React DevTools provides a visual interface to inspect component trees, examine props and state, profile performance, and debug React applications.

Question 4

What is a snapshot test?

Accepted Answer

A test that renders a component and compares the output to a previously saved reference to detect unintended changes

Answer

Snapshot tests capture the rendered output and compare it against a stored snapshot. Differences are flagged, alerting you to unintended UI changes.

Question 5

What is error boundary in React?

Accepted Answer

A component that catches JavaScript errors in child components, preventing them from crashing the entire app

Answer

Error boundaries catch errors during rendering and display fallback UI instead of crashing. They use componentDidCatch and static getDerivedStateFromError.

React Practice Test

React Practice Test

React Testing and Debugging