JavaScript

reactjs/react.dev: Fix stream demos on iOS Safari (#8613)

Fix stream demos on iOS Safari (#8613)

The "USB-C" for AI That's Fixing the M N Integration Problem

What is MCP, and where did it come from? In November 2024, Anthropic released the Model Context Protocol (MCP) — often described as the "USB-C for AI." It solves what's known as the M×N integration problem. Before MCP,…

oven-sh/bun: Bun v1.4

To install Bun v1.4 curl -fsSL https://bun.com/install | bash # or you can use npm # npm install -g bun Windows: powershell -c "irm bun.com/install.ps1|iex" To upgrade to Bun v1.4.0: bun upgrade Read the blog post:…

A Guardrail Can Hide a Tool Result Without Undoing the Action

OpenAI Agents JS 0.17.0 clarifies a subtle boundary around guardrails, tool-result replay, and retained copies. A guardrail may keep a tool result out of the model’s next replay, but that does not automatically reverse…

We caught a SQL injection with an offline AI security scanner — here's the exact query it found

The bug Here's a login endpoint from a small Express demo app (scan-target-demo-apps/apps/01-sql-injection): app.post('/login', (req, res) => { const { username = '', password = '' } = req.body; const query = `SELECT…

Autonomous AI Agent Orchestration: Scaling Multi-Agent Systems in Production

Transitioning generative models from isolated chat interfaces into production-grade multi-agent frameworks requires solving complex coordination challenges. As organizations scale autonomous workflows, naive prompt…

A Beginners Guide To Closures

Introduction If you've been writing JavaScript for some time now, you've probably used a closure without realizing it, maybe in a setTimeout, an event listener, or a function that returns another function. Closures are…

The Dependency Graph Is the Type: Meet InferDI

Most TypeScript dependency injection containers type services. InferDI goes further: it types the dependency graph itself. As you register services, the container's type evolves with the graph. TypeScript knows which…

Who Can Join a MERN Full Stack Course?

Who Can Join a MERN Full Stack Course? A MERN Full Stack Course is suitable for anyone who wants to build a career in modern web development. The course can be particularly useful for students, fresh graduates,…

Your generated file is the claim. Test it like one: reading a theorem back out of a WAV

Last night I generated a three minute film whose soundtrack is supposed to be a mathematical object. Not music inspired by it. The object itself, performed. The object is a rhythmic tiling canon: a set of onsets A, a…

Computing WHO growth percentiles on-device

Every baby tracker shows growth percentiles. "Your daughter is in the 72nd percentile for weight." It looks like a lookup — find the row for her age, compare, print a number. It isn't. And the ways it goes wrong are…

How a Simple Calculator for My Father Turned Into a Growing Web Platform

A few months ago, I built a small tool for one person: my father. He likes playing Lotofácil, a popular Brazilian lottery, and used to spend a lot of time doing combinations and calculations manually on paper. One day I…

Random pairing gets surprisingly tricky once you try to avoid repeats

I thought a "random pairing" tool would be a half-hour job. Shuffle a list, take names two at a time, done. The annoying part only showed up when I tried to make it usable for recurring things like coffee chats, book…

A missing exchange rate is not an exchange rate of 1

This is a submission for DEV's Summer Bug Smash: Smash Stories powered by Sentry. var fx = (rates.rates && rates.rates[v.currency]) || 1; That line converts a crypto price into whatever currency the visitor picked. It…

I asked a mapping API for lakes named Huron. It sent me Lake Baikal.

I was testing a geospatial library against a public demo server and sent it a filter: GET /collections/lakes/items?filter=name LIKE '%Huron%'&filter-lang=cql2-text It replied 200 OK. It reported 25 matches. Here is what…

How to Convert PDF to Word in the Browser with Vue 3 and pdf-lib

Converting PDF to Word seems straightforward, but the reality is more complex. PDF stores text as character coordinates, while Word uses structured paragraphs. Bridging this gap requires careful text extraction and…

Autism Treatment, Speech Therapy, Hearing Aid Centre for Kids & Children in Ludhiana Punjab

I Built DEVRIAN: Privacy-First Developer Tools That Run in Your Browser

How many times have you opened a random website just to format JSON, decode a JWT, generate a UUID, test a regex, or calculate a hash? I’ve done it more times than I’d like to admit. The annoying part isn't the task…

I got tired of writing boilerplate imports, so I built Block: Run Python, JS, and Lua in a single file

💡 The Problem: The Import / Glue Code Headache A while ago, I was practicing importing modules across different projects. I wanted to use Python for its rich data science libraries and Node.js for its async web…

Salary Attendance Calculator – A Simple Tool for Employee Pay Estimation

Tracking employee attendance and calculating monthly salaries can become repetitive for businesses. A salary-attendance calculator provides a convenient way to estimate employee pay using salary and attendance…

Convertendo Tabelas Web em Instruções SQL INSERT

Você tem uma tabela em uma página web. Precisa dela no seu banco de dados. A abordagem manual: copiar para o Excel, limpar, exportar CSV, escrever CREATE TABLE à mão, usar LOAD DATA ou COPY, debugar os erros. A…

Purpose of the useReducer hook in React

The useReducer hook is a state management hook in React that provides an alternative to the useState hook. It is used when the state of a component is complex and requires more than one state variable. Syntax: const…

What three JavaScript JSON parsers really return when an LLM's output is broken

Three JavaScript parsers, one pile of broken model output, twelve labelled cases. One run each, nothing tuned afterwards. Here is what each one actually returned — including the case where the best scorer confidently…

Give Claude Code your JetBrains IDE tools for free

Using Claude Code on a large codebase while keeping a JetBrains IDE open beside it? Give the agent access to what the IDE already knows. Explyt MCP connects Claude Code, Codex, Cursor, OpenCode, and other MCP clients to…

The Design Workflow That Makes an Expo Template Stop Looking Like an Expo Template

TL;DR Six defaults give away almost every Expo template: blue-500, Inter, Lucide outline icons, borderRadius: 12 cards, borderRadius: 8 buttons, and a "Nothing here yet" empty state. Three changes do most of the work in…

WHY YOUR REACT APP RE-RENDERS TOO MUCH (AND WHAT ACTUALLY FIXES IT)

A React page feels slow, so someone opens the code and starts adding memo, useMemo, and useCallback everywhere. Usually that makes the code harder to read before it makes the page faster. React rendering a component…

Fix Next.js "params should be awaited" Error in Next.js 15+

Fix Next.js "params should be awaited" Error in Next.js 15+ If you are seeing the params should be awaited Next.js error after upgrading to Next.js 15 or following an older App Router tutorial, you are not alone. The…

I Stopped Asking Cursor to “Fix My Code” Here’s What I Do Instead

Cursor is one of the most powerful AI coding editors available today. But if you've used it on a real React codebase, you've probably hit this frustrating pattern: you ask for a small change, and Cursor rewrites half…

I Built ChessIQ to Train Positional Chess Evaluation, Not Just Tactics

If you've played competitive chess, you've probably hit this moment: Neither side has a tactic. Nothing is hanging. No forced combination to calculate. But a strong player glances at the board for three seconds and…

Best Web Development Course in Laxminagar: Build the Skills to Create Modern Websites

Best Web Development Course in Laxminagar: Build the Skills to Create Modern Websites In today's world every business needs a strong online presence. From startups and local shops to companies, websites play an…

Modern Concurrency: From Execution Models to Production Reliability

Concurrency programming can be reduced to three questions: How do we divide work? How do tasks coordinate? How do we protect shared state? Languages and runtimes provide threads, coroutines, event loops, actors, and…

How I Built a Context-Dependent Core Belief Detector in 110 Lines of Vanilla JavaScript - No AI, No NLP, No Attention Mechanism

The same words mean different things in different contexts. "I'm not good enough" at work means I'm incompetent. "I'm not good enough" in a relationship means I'm unlovable. "I'm not good enough" with family means I'm a…

Prevent Optimizely from being blocked by ad-blockers using AWS

Category: Privacy Some ad-blockers might block Optimizely from running. In this tutorial, we’ll see how we can prevent this from happening. Ad-blockers will often look at the domain the request is originating from and…

We Can't See What You Paste — And That Was a Design Constraint, Not a Slogan

We can't see what you paste. No logging. No uploading. Just your browser. That's not marketing copy I wrote after the fact — it's a description of how FormatStack is actually built. Every tool (JSON formatter, regex…

The x402 ecosystem quietly split — and your endpoint may be unpayable

We run 19 paid x402 services — 800+ endpoints selling data to AI agents for USDC micropayments. Last week we tried to pay one of our own endpoints with the most-installed x402 npm client. It couldn't. No error. No…

The End of useMemo: React Compiler in Next.js

The Exhausting Re-Render Crisis For the past decade, building highly interactive React applications has been a delicate balancing act. React’s core architecture dictates that when a component's state or props change,…

Why input.value = 'x' doesn't fill a React form (and what actually works)

If you have ever tried to script a React form — a test helper, a browser extension, a bookmarklet, an onboarding demo — you have probably hit this: document.querySelector('#email').value = 'test@example.com'; The field…

I built 59 free browser-based dev tools in vanilla JS — here's what I learned

I've been quietly building Antigravity Tools — a collection of 59 free, browser-based developer utilities — and today I'm sharing everything I built and learned. Why vanilla JS? No React, no build step. The main…

10 Best Platforms for Buying OnlyFans Accounts In 2026

Buy Old OnlyFans Accounts – Security, Privacy, Account Management & Safer Alternatives 🌟💬 24/7 Premium Support — Always Here for You! 🤝✨ 📱💎 WhatsApp: +1 (506) 541-7768 ✈️🚀 Telegram: @usadigitalhub 🎮🔥 Discord:…

Logging Done Right: A Practical Guide

Logging Done Right: A Practical Guide Logging is one of those things we all do, but rarely do well. I've spent years sifting through tangled log files, and I've learned that a little discipline goes a long way. Here's…