JavaScript

Getting 'Cannot find native binding' for @tailwindcss/oxide in a pnpm workspace with Next.js Turbopack? Here's why it happens and how to fix it.

Trigger a React error boundary by throwing during render, testing the fallback in Jest, and using showBoundary for async or event-handler errors.

Fix `IntersectionObserver is not defined` in Jest by adding a clean global mock in `jest.setup.ts`. Includes TypeScript-safe setup and a test example.

Detect a click outside a modal or dropdown in React with Node.contains(), and close it by checking if the clicked element is a descendant.

Enforce named functions inside useEffect for better debugging and stack traces.

TypeScript types event.target as EventTarget, which has no value. Use React.ChangeEvent<HTMLInputElement> or cast the target to HTMLInputElement.

useRef(null) without a type argument leaves ref.current typed as 'never'. Pass the element type, like useRef<HTMLInputElement>(null), to fix it.

jsdom in Jest has no window.matchMedia, so components that call it throw a TypeError. Add a matchMedia mock to your Jest setup file.

Fix CORS errors in json-server with a custom server.js and middleware. Covers preflight OPTIONS requests and when to use wildcard vs specific origin.

Discover 5 simple applications to enhance your JavaScript skills. Dive deeper into learning by trying out these JavaScript examples today!

Fix the Jest jsdom error "Not implemented: window.scrollTo" by mocking window.scrollTo in your setup file. Includes a test to confirm that the mock works.

Fix "ResizeObserver is not defined" in Jest by mocking ResizeObserver in your setup file, so tests for components that use it run in jsdom.

Simple way to test Next.js Image in Jest by mocking it as a plain img tag, plus checks and common mistakes.

Simple way to test next-i18next in Jest by mocking translation hooks so component tests stay focused and stable.

Fix Jest "Cannot use import statement outside a module" when mocking Swiper by adjusting transformIgnorePatterns.

Fix the Jest EMFILE too many open files error by lowering maxWorkers, ignoring build folders, raising ulimit, and running in band on CI.

Mock Next.js useRouter in Jest with reliable patterns for pathname, query, and push assertions in component tests.

Easily start node project by using nodemon and babel

How to keep only specific Moment.js locales in Webpack to reduce bundle size and avoid loading every locale.

Find exactly where window.scrollTo is called in Jest tests using console.trace, jest.spyOn, and a few quick steps to narrow down the caller.