How do you test React applications?

Testing React Applications

When it comes to testing React applications, I follow a comprehensive testing strategy that ensures our applications are reliable and maintainable. The foundation of my testing approach uses Jest as the test runner along with React Testing Library, which follows the philosophy of testing components the way users actually interact with them.

There are four main and important types of testing:

• End-to-End (E2E): Uses a helper robot that behaves like a user to click through the app and verify that it functions correctly. Also known as "functional testing" or "e2e".
• Integration: Verifies that multiple units work together in harmony.
• Unit: Verifies that individual, isolated parts work as expected.
• Static: Catches typos and type errors as you write the code.

To implement these types of testing, we can use the following tools:

• React Testing Library: We can use this for performing unit and integration testing.
• Jest (test runner): We can use this for performing unit and integration testing.
• Mock Service Worker (API mocking): We can use this for performing integration testing.
• React Hooks Testing Library (for testing hooks): We can use this for performing unit testing of react hooks.
• Cypress / Playwright (end-to-end testing): We can use this for performing end-to-end testing.