How to avoid infinite re-renders with React's useEffect

💡 From Vanilla JS → React → Redux Toolkit: Full Circle Moment This week I have been exploring Redux Toolkit and had a fun realisation. In React, we never mutate state and always return new objects with useState. Then with Redux Toolkit, I wrote this: state.push(action.payload) …and it just worked. Why? Immer handles immutability under the hood. It lets us write “mutating” code while keeping state updates safe and predictable. Feels like a full circle: from mutating in vanilla JS → immutable in React → “mutating safely” in Redux Toolkit. ✅ Lesson: Redux Toolkit makes state management clean, simple, and safe. #React #ReduxToolkit #JavaScript #WebDev #StateManagement

Staring at the screen, wondering why your React component re-renders endlessly? I've been there. I was debugging a sluggish dashboard last week. The profiler showed one component re-rendering like crazy. 🤯 The culprit? A simple inline arrow function passed as a prop: `<ChildComponent onClick={() => doSomething()} />`. On every parent render, we were creating a 𝐧𝐞𝐰 𝐟𝐮𝐧𝐜𝐭𝐢𝐨𝐧 𝐢𝐧𝐬𝐭𝐚𝐧𝐜𝐞. This breaks `React.memo` because the prop is never truly the same. It's a classic trap! 💡 Wrapping that handler in `useCallback` stabilized the component instantly. A small change with a huge performance win. 🚀 Have you struggled with this before? #ReactJS #FrontendDevelopment #DeveloperTips

Ever spend an hour on a bug that turned out to be a one-line fix? I did yesterday. My component was stuck in an infinite re-render loop, and my network tab was on fire. 🔥 The culprit? A `useEffect` hook where I passed an object directly into the dependency array. Since a new object reference is created on every render, React saw a "new" dependency and re-ran the effect. 𝐄𝐯𝐞𝐫𝐲. 𝐒𝐢𝐧𝐠𝐥𝐞. 𝐓𝐢𝐦𝐞. It’s a classic trap that still gets me when I'm moving too fast. 🧠 Reminder: for non-primitive values in a dependency array, stabilize them with `useMemo` or `useCallback`. Have you struggled with this before? #ReactJS #FrontendDevelopment #DeveloperTips

React Developers: Are your components suffering from useEffect misuse? The useEffect hook is powerful, but easily misunderstood. Misplaced dependencies, forgotten cleanups, and derived state issues are common culprits for bugs and performance hits. In my latest blog post, I break down the 4 most critical useEffect anti-patterns I see in professional codebases (including the dreaded infinite re-render loop): Dependency Array Pitfalls (Stale closures, unstable objects) Derived State Misuse (When to use useMemo or just compute on render) Cleanup Failures (The memory leak trap) Misapplication (Using effects for what belongs in event handlers) Master these best practices to write cleaner, more performant React. Click to read the expert debugging guide: [ https://lnkd.in/g9NpcKBq ] #Reactjs #FrontendDevelopment #CodeQuality #ProgrammingTips #SoftwareEngineering

React 19 Alpha is here! Panel 1: React 19 Alpha  The new era of React begins! Featuring the upcoming React Compiler that automatically optimizes components—no more manual useMemo or useCallback. Plus, Server Components & Actions make apps faster by keeping heavy work on the server. Panel 2: New Hooks & Features  Developers, get ready! React 19 introduces fresh hooks like useActionState, useFormStatus, and useOptimistic, along with the new use() API for simpler async data handling. Panel 3: Performance & Ecosystem Growth  Expect huge performance gains and a rapidly growing ecosystem—React is evolving faster than ever. #React19 #WebDevelopment #JavaScript #Frontend #ReactJS

Built a React state management library: react-snap-state ⚡ It is a lightweight, key-based state management library for React 17+ built on top of useSyncExternalStore. 1. Key-based reactivity 2. No context re-renders 3. Less than 15KB unpacked 4. TypeScript-ready 5. Ready for concurrent rendering 6. Uses use-sync-external-store/shim for React@17 👉 npm: https://lnkd.in/dBwrGcmk 👉 GitHub: https://lnkd.in/dF7HqVTr Building this from scratch was a great way to explore React internals, store subscriptions and concurrent rendering in depth. #ReactJS #JavaScript #TypeScript #OpenSource #WebDev

🎉 Just released a tiny one I've been using internally @mateosuarezdev/attempt - an utility for explicit error handling in TypeScript. Tired of nested try-catch blocks? This library treats errors as values, not exceptions, making your code cleaner and safer: ✨ No try-catch boilerplate ✨ Explicit error handling with TypeScript type inference ✨ Array destructuring for flexible variable naming ✨ Works with custom error types across your app ✨ Supports both sync and async operations Perfect for DB Queries, API calls, JSON parsing, or any operation where you want predictable error handling. Built as a standalone package after extracting the pattern from my apps. Get started: npm install @mateosuarezdev/attempt yarn/pnpm/bun add @mateosuarezdev/attempt Repo: https://lnkd.in/dsVrK7Yb Check it out and let me know what you think! #typescript #javascript #trycatch #errors #bun #node #react

🚀 Exploring React 19: Auto-Memoization with the React Compiler In today's exploration of React 19, I delved into the new React Compiler, a game-changer for performance optimization. 🔍 What's New? The React Compiler now automatically applies memoization to your components, reducing the need for manual useMemo or useCallback hooks. This feature enhances performance by preventing unnecessary re-renders, leading to smoother user experiences. 💡 Why It Matters: Simplifies codebase by eliminating redundant memoization logic. Improves application performance without additional developer overhead. Allows developers to focus more on building features rather than optimizing renders. 🔗 Learn More: For a deeper understanding, check out the official React 19 release notes: React #ReactJS #React19 #WebDevelopment #FrontendDevelopment #JavaScript #PerformanceOptimization

💠 Understanding the Cleanup Function in React 🔹 When React components run effects (like fetching data, setting up event listeners, or using timers), sometimes those effects keep running even after the component is gone or re-rendered. 🔹 That’s where the cleanup function comes in. 🔹It helps “clean up” or cancel anything that shouldn’t continue once the component is unmounted or updated.  ▫️ Why Cleanup Is Important 🔸 Without cleanup functions, your app can 🔸Keep running unnecessary background tasks Cause memory leaks 🔸Lead to unexpected behavior when the component re-renders ▫️ Real-Life Use Cases 🔸Clearing timers or intervals 🔸 Removing event listeners 🔸Canceling API requests 🔸 Disconnecting WebSocket connections #ReactJS #WebDevelopment #Frontend #JavaScript #LearnReact #CodingTips #ReactHooks #CleanCode #DeveloperCommunity

I am not dunking on Next.js, but at this point it's not enjoyable to write react with next.js. The Pages router was good but things change and I understand. I have great respect for people who have worked on Next.js and consequently vercel. The addition of directives is also specific to turbopack, compiler for next, we can't say the same thing about parcel, vite, rspack etc. I would much rather go with Tanstack start over remix v7 or other alternatives because even remix has marked its departure from react to signals based API. Frameworks change, ideas evolve and there are better ways to do things and we have to adapt but with that being said whether we like it or not Next.js has had an enormous impact on the React ecosystem and I'm afraid we're not going to be seeing anymore of the react we used to like. But Tanstack start I believe is offering something that I'm not seeing in other frameworks -> Explicit decision making over implicit magic. The design is neat and I'm sure the dev community will appreciate the thought process behind its design. A developer should understand why we're using the 'use client' or 'use server' directive and understand its internals rather than knowing the surface level. Remix v6 tried to introduce that concept with loaders and it refreshed our perspective with Forms API and I'm sure Tanstack start will do a great job in bringing the concepts of SSR closer to the user. You should try Tanstack start today.