userEvent vs fireEventin React Testing
React Testing Library gives you two ways to simulate interaction, but only one behaves like a real user and exposes the bugs that matter.
Read ArticleWhat Is Browser Paintingand How Does It Work?
If you've ever wondered what actually happens between React calling setState and something appearing on your screen, the answer lives in the browser's rendering pipeline and painting is its final, visible act.
Read ArticleTaming the DOM withuseLayoutEffect and useRef
When layout-sensitive logic has to run before paint, this pair gives you precise control without the flash that often comes with a regular effect.
Read Articlejest.fn() vs jest.mock()Know the Difference
Both create fakes. But one replaces a function, the other replaces an entire module, and confusing the two leads to tests that do not work the way you think.
Read Article