React has revolutionized web development by abstracting away the details of DOM manipulation. That conceptual elegance has opened the door to a new generation of web testing: clear, expressive, and lightning-fast. That makes React a perfect fit for test-driven development (TDD), a methodology in which tests are a blueprint instead of an afterthought. Each chapter will present new projects to challenge you and new tools to help you. Write fast, portable tests with Jest. Keep your code tidy with ESLint and Prettier. Perform every task you need from a single window with VS Code. See your test output directly in your code with Wallaby. Use the JavaScript features of the future with Babel. Make assertions about React component behavior with Enzyme. And style components in a testable way with styled-components. By understanding every piece of your project's stack, you'll feel more confident and able to focus on what matters: writing reliable and maintainable code. Discover a more joyful React development experience. Let your tests lead the way! You'll need a working knowledge of JavaScript and a computer running macOS, Windows, or Linux.