Shallow rendering is a technique used in React testing where a component is rendered only one level deep.
It renders the component without rendering its child components.

When and why use shallow rendering:

• To test a component in isolation without worrying about the behavior of its children.
• To focus on the component's internal logic, props, and state changes.
• Useful for unit tests where you want to test one specific component alone.

Example with Enzyme:

import { shallow } from 'enzyme';
import MyComponent from './MyComponent';

test('renders title', () => {
  const wrapper = shallow(<MyComponent />);
  expect(wrapper.find('h1').text()).toBe('Hello World');
});

Important note:
Today, shallow rendering is used less frequently because libraries like React Testing Library promote testing based on user interactions, not component internals.

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