How do you test async behavior in React components?

Short answer: Testing async behavior often involves waiting for a component to update based on API calls or timeouts.

Example code

Use waitFor or findBy queries to wait for async changes. import { render, screen, waitFor } from '@testing-library/react'; import MyComponent from './MyComponent'; test('loads data asynchronously', async () => { render(<MyComponent />); // Wait for the element that should appear after the async call await waitFor(() => screen.getByText('Loaded Data')); expect(screen.getByText('Loaded Data')).toBeInTheDocument(); }); In this case, waitFor() waits until the expected element appears in the DOM after an async operation completes.

Real-world example (ShopNest)

ShopNest’s storefront is React: components for ProductCard, CartDrawer, and CheckoutForm, with hooks for local UI state.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.