#101 Knowledge of any testing library to do testing in React

Yes ✅, here are some popular testing libraries used in React along with what they are used for:

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🔸 1. Jest (by Facebook)

• Default testing framework used with React.
• Can test JavaScript logic, components, async code, etc.
• Comes with built-in test runner, assertions, and mocking support.

npm install --save-dev jest

test('adds 2 + 2', () => {
  expect(2 + 2).toBe(4);
});

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🔸 2. React Testing Library (RTL)

• Helps test React components based on user behavior.
• Focuses on how your component renders & interacts, not the internals.
• Often used with Jest.

npm install --save-dev @testing-library/react

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

test('renders welcome message', () => {
  render(<App />);
  const linkElement = screen.getByText(/welcome/i);
  expect(linkElement).toBeInTheDocument();
});

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🔸 3. Enzyme (by Airbnb – legacy)

• Allows testing React components with a shallow, mount, or render API.
• Not actively maintained; not recommended for React 18+.

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🔸 4. Cypress (for E2E testing)

• Used for end-to-end (real browser) UI testing.
• Simulates real user actions like clicks, typing, etc.

npm install --save-dev cypress

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✅ Recommendation:

• Use Jest + React Testing Library for unit and component testing.
• Use Cypress for end-to-end and integration testing.