How do I test asynchronous code in React Testing Library?

How do I test asynchronous code in React Testing Library?

You can use the waitFor function to handle asynchronous code in your tests. It allows you to wait for a specific condition to be met.

Can you show me an example of using waitFor?

Sure! Here's a simple example:

import { render, screen, waitFor } from '@testing-library/react';
import MyComponent from './MyComponent';

test('loads and displays greeting', async () => {
  render(<MyComponent />);
  await waitFor(() => expect(screen.getByText('Hello, World!')).toBeInTheDocument());
});

What if I need to test a promise that resolves?

You can still use waitFor. Just ensure that your component updates the UI when the promise resolves, and waitFor will handle it.