Dependency Arrays are finally dead ⚰️ . The most annoying part of React has always been manual memoization 👇 . Should I wrap this in useMemo? Did I miss a variable in the dependency array []? Why is this component re-rendering? 👉 We spent years fighting with useCallback and React.memo to prevent unnecessary renders. React 19 paves the way for the React Compiler (formerly React Forget). ❌ The Old Way (Manual): You act as the compiler. You manually tell React: "Only re-calculate this if [x, y] changes." It bloats your code and is the #1 source of stale closure bugs. ✅ The Modern Way (Automatic): You write plain JavaScript. The Compiler analyzes your code at build time. It automatically memoizes values and functions that need it. • No useMemo: Deleted. • No useCallback: Deleted. • No Dependency Arrays: Gone. The Shift: React is finally becoming truly "Reactive." You focus on the logic; React focuses on the performance. Note: The React Compiler is an optional build-time tool compatible with React 19. #ReactJS #React19 #ReactCompiler #WebDevelopment #Frontend #JavaScript #CleanCode #SoftwareEngineering #TechTips #ReactFeature #ReactHooks #Hooks #ReactTips #FrontrendDeveloper #DevloperTips
The React Compiler is promising, but this framing is misleading. Dependency arrays, useMemo, and useCallback are not “dead” today. The React Compiler is optional, still evolving, and not enabled by default in most production apps. Even with the compiler: • You still need to understand render behavior • Memoization is reduced, not magically eliminated • Existing apps won’t change unless they opt in and follow compiler constraints This is a direction, not a replacement yet. Understanding React fundamentals still matters more than assuming the compiler will fix everything. Context > hype 👍
According to the official docs, you still need to know useMemo or useCallback when you want to make sure the value that is used in the useEffect is memoized, and you stop the infinite loops from happening. Link: https://react.dev/learn/react-compiler/introduction#what-should-i-do-about-usememo-usecallback-and-reactmemo
Mastering the dependency array is crucial to understand reacts render behavior and trace back these unnecessary rerenders. The compiler will make that job easier but won't replace the need to understand them
Dependency arrays aren’t dead just misunderstood. React Forget is experimental,not a replacement for understanding render behavior,reference equality, and memoization.
This feels so wrong after doing everything manually for so long
Dependency arrays are still required for effects
ah, magic wrapped in another magic. One couldn’t whish more 🥳
I still use this hooks. In some place they are just needed.🥱
Is it compatible with the Vite bundler?
This isn't a runtime change. It's a build-time revolution. The React Compiler (babel plugin) essentially "rewrites" your components during the build process to insert the memoization slots for you. It’s the same optimization you used to write by hand, but now a machine does it perfectly every time. 👍 ☺️