JavaScript Weekly developer newsletter

Plus Bun's new built-in type checker, Partytown 1.0, and an obscure way to call functions without parentheses. #806 — October 13, 2026 Read on the Web Together with JavaScript Weekly Deno is Joining Cloudflare (But…) — Maybe David Bushell saw the writing on the wall, as the Deno team isn't joining Cloudflare to keep working on Deno, but to fold celld into workerd so Durable Objects can be self-hosted (more on that here). The Deno runtime will get a final year of official fixes, Deno Deploy closes in six months, and JSR moves to Cloudflare's infrastructure. Ryan Dahl 💡 On Hacker News, Ryan Dahl noted that Deno "has been sucked into the gravity well of Node compatibility" before asking: "Why reimplement Node? It works." But what happens to the JavaScript™ trademark case, I wonder…? CodeAF: #1 of Ten Coding Harnesses on DeepSWE — Ten coding harnesses ran the same open model on 113 real GitHub issues. CodeAF solved the most and paid the least per solved issue: 3.4x less than Claude Code, 4.8x less than OpenCode. A new open-source coding harness built for open models. AgentField AI sponsor Bun 1.4.3 Adds bun check, a Built-In TypeScript Type Checker — bun check is a port of TypeScript 7's checker that reads your tsconfig.json, reports the same errors as tsc and, Jarred claims, runs 3-6x faster. It plugs into bun run/test/build too. Idle server processes now use far less CPU, and a JavaScriptCore upgrade picks up numerous perf gains. Jarred Sumner IN BRIEF: AWS has launched Lambda Web Functions, which run an ordinary port-listening Node server (Express, Hono, Fastify, etc.) on Lambda with no handler rewrite, billing for active CPU time and separately for memory. 📊 The 2026 Stack Overflow Developer Survey results are out (30,903 people took part) with JavaScript the #1 language for the 12th year in a row (and TypeScript at #6). 🔒 Despite this week's fresh stir, no malicious Zod release reached npm. Malicious commits pushed to its repo in September were reverted the same day, as Colin McDonnell explains. 🔒 An out-of-band Next.js security release is due tomorrow. RELEASES: Last second addition: TanStack Start 1.0 has just dropped. Big news for full-stack React and Solid fans! :-) 🎉 Partytown 1.0 – A popular way to relocate third-party scripts to run in a Web Worker rather than on the main thread has left beta after five years in development. Marionette 5.0 – Six years on, the Backbone-era framework returns with a core free of Backbone, jQuery and Underscore… and they explain why! Bootstrap 6 Alpha – An early look at Bootstrap's first major release since 2021, leaning on modern CSS and making its JavaScript plugins ESM-only. Express 5.3.0 – A maintenance release worth upgrading to, as patched qs, proxy-addr and body-parser dependencies close five CVEs. 📖 Articles and Videos 📊 WebSocket Servers in JavaScript: Node.js, Bun, and Deno — In 2023, Daniel found Bun much faster than Node at relaying WebSocket messages, but there was a bug in his Bun server. This new attempt uses a C client/relay as a baseline, and Node 26 now gets close to C latency, ahead of Bun and Deno. Daniel Lemire How Sindre Sorhus' Personal Site is Now Made in Swift — One of JavaScript's most prolific developers explains how he's dropped Astro and now builds his personal site with Swift, including the styling and markup, with broken links and style typos failing at compile time (source). Sindre Sorhus Too Many Agent Traces to Read? Find the Ones That Matter, Live Oct 14 — Bad answers, wrong tool calls, too many traces. See how Sentry engineers find the failures worth fixing. Register now. Sentry sponsor Tiny Apps with TinyJS — A quick look at a new way to make tiny JS-powered desktop apps we featured a few weeks ago. Raymond Camden 📄 Yet Another Way to Invoke Functions Without Parentheses – There are many ways to invoke arbitrary functions in JavaScript without using parens, but this is a particularly obscure one! bartosz 📄 Six M