Скачать или смотреть Gen Z JavaScript: Unit Testing in React (Jest & React Testing Library Masterclass) 12 October 2025

link: https://codesandbox.io/p/devbox/z627r...

Welcome back to the Gen Z JavaScript series! Today, we're diving into a crucial topic that separates junior developers from seniors: Unit Testing in React!

Writing tests ensures your application is stable, reliable, and bug-free, especially as it grows. We'll show you exactly how to set up and start writing effective unit tests for your React components using the industry-standard combination of Jest and the React Testing Library (RTL).

In this comprehensive tutorial, you will master:

Jest Fundamentals: Setting up the powerful JavaScript testing framework.

React Testing Library (RTL): Focusing on testing the user experience, not the implementation details.

Querying the DOM: Using getByRole, getByText, and other queries to find elements like a real user.

Simulating User Events: Testing click handlers, input changes, and other user interactions.

Assertions: Using Jest's matchers (like toBeInTheDocument) to verify expected outcomes.

Practical Examples: Testing a simple component to ensure it behaves correctly.

Mastering unit testing is vital for your professional development journey in React and beyond.

Stay tuned for more essential JavaScript, React.js, and Angular concepts!