What is test coverage in React and why is it important?

What is test coverage in React and why is it important?

Test coverage in React refers to the percentage of your code that is tested by automated tests. It's important because it helps ensure that your application behaves as expected and reduces the likelihood of bugs.

How can I measure test coverage in my React application?

You can measure test coverage in a React application using tools like Jest and React Testing Library. Jest provides built-in coverage reporting that you can enable by running your tests with the --coverage flag.

What are some best practices for achieving high test coverage?

Some best practices include writing tests for critical components, using snapshot testing, and ensuring that both unit and integration tests are included.

Can you give me an example of a simple test case in React?

Sure! Here's a simple example using Jest:

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

test('renders learn react link', () => {
  render(<MyComponent />);
  const linkElement = screen.getByText(/learn react/i);
  expect(linkElement).toBeInTheDocument();
});