How do you test a React application?

There are several ways to test a React application, including:

1. Unit testing: Testing individual components or small portions of the code using tools such as Jest and Enzyme.

2. Snapshot testing: Taking a "snapshot" of a component's rendered output and comparing it to the snapshot in future tests to detect changes.

3. End-to-end testing: Testing the entire application in a real browser using tools such as Cypress or Selenium.

4. Integration testing: Testing how different components interact with each other.

5. Performance testing: Testing the performance of the application using tools such as Lighthouse.

6. Accessibility testing: Testing that the application is accessible to users with disabilities using tools such as aXe or pa11y.

It's important to note that different types of tests are more suited for different purposes and you should choose the right type of test for the specific problem you're trying to solve.