JavaScript Weekly

What's new in ECMAScript 2026 (and usable today)

Tue, 7 Jul 2026 00:00:00 +0000

#793 — July 7, 2026

JavaScript Weekly

Vite+ Beta: A Web Dev Toolchain Behind One Command — Vite+ is the Vite team’s ‘unified toolchain’ that brings Vite, Vitest, Oxlint, and similar tools together under a single vp command, whether for running a dev server, tests, formatting, or bundling.

VoidZero

💡 Vite+ was originally intended to be a commercial project to fund work on Vite and related projects, but was open sourced under the MIT license earlier this year.

Still Writing Tests Manually? Meticulous AI Is Here — Notion, Dropbox, Wiz and LaunchDarkly now use a testing paradigm they can’t work without. Built by former Palantir engineers, Meticulous automatically creates an evolving suite of E2E UI tests, delivering exhaustive coverage with no developer effort.

Meticulous sponsor

What's New in ECMAScript 2026 — The 876 page ECMAScript 2026 spec was approved last week, and this round-up covers several main new features that made the cut, from Array.fromAsync to native Uint8Array Base64/Hex conversion, with examples for each. All are already in browsers and runtimes (except Math.sumPrecise in Node) so you can likely use them today.

Pawel Grzybek

IN BRIEF:

🕹️ js1024, the annual 1KB code-golf competition, is open for entries. The theme is 'dreaming', and you've got 1,024 bytes to make something neat. Here's last year's winner to get a feel for the caliber.
There's a TC39 proposal to standardize a code property on Error (long a de-facto Node convention). Its champion, James Snell, hopes to advance it at this month's plenary.

RELEASES:

vinext 1.0 Beta – Cloudflare's Vite plugin reimplementing Next.js's API surface.
webpack-dev-server 6.0 – The official webpack dev server with live reloading upgrades to Express 5 and native ESM.
Dependency Cruiser 18.0 – Tool to validate and graph project dependencies.
npm 11.18.0, pnpm 11.10

📖 Articles and Videos

Working with AI: A Concrete Example — The creator of htmx reflects on the role of AI in his work with a practical example of using Claude to investigate a bug report. He also touches on how AI fits in with being an ‘older developer’, a topic I rarely see brought up.

Carson Gross

How Medal Cut Its Electron Frontend Bundle from 40MB to 2.7MB — A gaming metaphor heavy tale of slashing an Electron app’s bundle from 40MB+ to 2.7MB using Vite, Rolldown, code splitting, and aggressive dead-code elimination.

Rick Zhang (Medal)

Streaming Real-Time HDR Reflections to Every Device with Miris — Miris built a WebXR car configurator that streams a 1.2GB asset in real-time with HDR reflections across any device.

Miris sponsor

📄 A Guide to Hydration and Rendering Strategies – SSR, streaming, islands, resumability, and RSC, compared. Neciu Dan

📄 WebGL Without a GPU – Useful tips for testing or taking screenshots of WebGL-rendered experiences. Kiko Beats

📄 Understanding TypeScript's Distributive Conditional Types Tejas Bubane

🛠 Code & Tools

Wordgard: A New Rich Text Editor Library from ProseMirror's Creator — With Eloquent JavaScript and ProseMirror under his belt, not many people know more about JavaScript and making good editor controls than Marijn. Modular, supports collaborative editing, and thoughtfully built. Live demo and how to get started.

Marijn Haverbeke

The TypeScript-Native AI Backend for Autonomous Software — Orchestrate agents as typed APIs — then spin up software factories that ship production-grade PRs. Open source.

Agentfield.ai sponsor

Astryx: Meta Open Sources Its Design System — A design system used by 13,000+ apps inside Meta is now open source with 150+ React components, theming options, dark mode, and CLI tooling.

Will npm v12 reject your .npmrc?

Tue, 30 Jun 2026 00:00:00 +0000

#792 — June 30, 2026

Read on the Web

JavaScript Weekly

Deno 2.9 Released — A huge release for the runtime: deno desktop turns scripts and framework-based projects into native, self-contained desktop apps, quick migration from npm/pnpm/Yarn/Bun lockfiles, big test runner improvements, ~2x faster cold starts, and a target of Node.js 26 compatibility.

Bartek Iwańczuk

44 Recorded PostgreSQL Talks Are Now Available to Watch — Explore 44 talks about PostgreSQL-backed app development, Postgres performance & AI, Postgres 19, Azure HorizonDB and more. All sessions are available on YouTube. Learn directly from Postgres experts at your own pace. Check out the playlist.

Microsoft | AMD sponsor

Iterating Faster on VS Code with TypeScript 7 — How the VS Code team incrementally adopted the Go-based TypeScript 7 compiler (currently in RC) while it was still being built. Type-checking the source went from 36s to 5s, with npm run watch going from 80s to ~20s.

The VS Code Team (Microsoft)

IN BRIEF:

The second preview release of npm 12 is available for testing. This is worth doing, as Colin McDonnell has already noticed npm 12 hard-errors on unrecognized keys in .npmrc files.
🔒 npm now locks 'high impact accounts' (maintainers of the most popular packages) into a 72-hour read-only mode when they change their email or use a 2FA recovery code.
The Svelte team has just posted the latest monthly Svelte update. In related news, Svelte creator Rich Harris was recently asked ▶️ for his takes on working with AI and Svelte.

RELEASES:

🤖 AI SDK v7 – Vercel's SDK that provides an abstraction for building against any AI model provider.
Node.js v26.4 (Current) adds experimental package map support to resolve packages from a static JSON file instead of walking node_modules.
Formisch v1 RC – Schema-first, headless type-safe form state library.
Prettier 3.9, Rspack 2.1, Electron 43, ESLint 10.6, pnpm 11.9

📖 Articles and Videos

Why Drizzle Couldn't Publish New Releases on npm for a Month — As well as explaining why the creators of the popular ORM ran into the problem, Evert shares some tips to see if you're at risk of the same problem, and how to avoid it entirely.

Evert Pot

The Shifting Line Between CSS States and JavaScript Events — A tour of the (more than you’d think) CSS pseudo-classes that can stand in for JS event listeners, plus a look at the experimental/future event-trigger syntax.

Daniel Schwarz

Real-Time Analytics on Your Operational Postgres Table — Polling just hides the lag. TimescaleDB's continuous aggregates keep data fresh on read. Get $1000 credit to start.

Tiger Data (Creators of TimescaleDB) sponsor

Blocking Install Scripts is Not a Silver Bullet — npm v12 won't run install scripts by default, but Ulises argues that only solves part of the supply chain security problem.

Ulises Gascon

Moving Linear from styled‑components to StyleX — A migration away from a runtime CSS-in-JS approach yielded ~30% faster renders when navigating between pages.

Kenneth Skovhus (Linear)

📺 How Tanner Linsley Built TanStack to Outlive Him – A very smoothly produced 15 minute interview with the creator of TanStack. The Build Log

📄 Benchmarking 5 WebSocket Servers for Node.js Irina Nazarova

📄 Handling Mutations with TanStack Query for Vue Marina Mosti

📄 Parsing Arbitrary Dates in Strings with Chrono and a Web Component Raymond Camden

🛠 Code & Tools

Nub: An All-in-One Toolkit That Augments Node.js — While Bun or Deno can replace Node, this project from Zod’s creator extends Node with nice-to-haves, like fuller TypeScript support, faster & more secure package installation, better .env handling, and a web-standard Worker.

Colin McDonnell et al.

Gea: A Compiler-First Reactive UI Framework — A UI framework that goes all in on "compile the framework away": no VDOM, JSX transformed into string templates, proxy-based stores, and 'surgical' DOM patching. The big win is tiny build sizes.

Armagan Amcalar

Stop Alt-Tabbing to the Dashboard When CI Breaks — Depot CI's new API and CLI let you query runs, pull logs, and diagnose failures without leaving your terminal.

Depot sponsor

<qr-code> 2.0: Web Component for Generating QR Codes — An easy way to display QR codes in the browser using pure JavaScript. A 13 year old solution that’s been modernized and is now ESM only. Live demo.

Eduard Castellano

spartan/ui 1.0: shadcn/ui-Style UI Primitives for Angular — If you’re an Angular developer who’s ever envied the copy and paste simplicity of shadcn/ui, this is for you.

Robin Goetz

Wakaru 1.6 – JavaScript decompiler and bundle splitter. Now with even better 'source-like' output, particularly from bundled React apps.
🎬 TurboRes 1.0 – Fast Zig/WASM-powered Apple ProRes video decoder for JS environments. From the creator of Mediabunny.
📊 ngx-charts 24.0 – Declarative charting framework for Angular. Interactive demo.
GopherJS 1.21.0 – A Go to JavaScript transpiler. Now supporting up to Go 1.21.13.
whatwg-url 17.0 – JS implementation of the WHATWG URL Standard. Demo.

📰 Classifieds

Flaky tests slowing down dev? Meticulous gives engineers confidence to ship faster by autonomously testing every edge case of your web app.

Build TypeScript-first AI agents in your codebase. No timeouts, durable queues, & full tracing. Ship your first agent in minutes with Trigger.dev.

📢 Elsewhere in the ecosystem

📊 Frank Denis wanted to see the performance of WebAssembly runtimes in 2026 and pitted nine options against one another, including Bun and Node/V8's options.
GitHub is continuing with efforts to make project management less overwhelming in the agentic era. Now you can restrict issue creation to collaborators with write access.
Meta has ported Flow, the static type checker for its typed dialect of JavaScript, from OCaml to Rust.
The pnpm project is working on pnpr, an experimental pnpm-compatible npm registry server, written in Rust.
Git 2.55 has been released with git history fixup for 'fixing up' earlier commits, faster git status on Linux, and more.
🐘 Postgres 19 is currently in beta, with the final release expected this September. Craig Kerstiens looks ahead to what's interesting in Postgres 19 for users and developers.

Babel 8.0, Vite 8.1, and TypeScript 7.0 RC

Tue, 23 Jun 2026 00:00:00 +0000

#791 — June 23, 2026

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JavaScript Weekly

Desktop Apps With deno desktop — Deno 2.9 (or the 'canary' build now) can turn JavaScript projects into self-contained apps on macOS, Windows, and Linux. Unlike Electron, you can opt to use the default OS WebView or a bundled Chromium backend, plus you get cross-compilation and automatic support for apps built on frameworks like Next.js and SvelteKit.

The Deno Project

📉 It's not in the post, but a --compress option gets packaged app sizes down a lot – from 65MB to 19MB in my test with a basic app.

Catch Runtime Bugs Before Your JS PR Merges — Some JavaScript bugs only show up after the app runs. Greptile reviews each PR with full repo context, runs the code in a sandbox, and returns screenshots, logs, and traces as proof of what broke. Use Greptile in GitHub, GitLab, or from your terminal.

Greptile sponsor

Babel 8.0 Released: The JavaScript Transpiler — It’s been eight years since Babel 7.0, and despite the rise of tools like SWC and Oxc, weekly downloads of the @babel packages have increased 380x since. v8.0 is a modernization release that goes ESM-only and targets ~ES2023 by default (vs ES5 before).

Babel Team

TypeScript 7.0 Release Candidate — A step closer for the Go-powered TypeScript compiler that promises ~10x faster build performance. (I've seen people on social media getting very excited by this.)

Daniel Rosenwasser (Microsoft)

IN BRIEF:

Cloudflare has added the ability to create and deploy Workers on 'temporary accounts'. Ostensibly 'for AI agents', but you can use them yourself too, and get a Worker running for 60 minutes with no strings attached.
TC39 delegate Luca Casonato has made a proposal to add built-in localized time formatting to <time>, akin to GitHub's <relative-time> element.
🤖 MDN has introduced an official MCP server to provide better access to MDN's up-to-date JS and frontend docs to coding agents.
The Bun team has proposed adding shared-memory threads to JavaScriptCore (a more traditional threading approach versus worker threads).

RELEASES:

⭐ Vite 8.1 – Adds experimental support for 'bundled dev mode' which radically speeds up dev server startup and full reloads on large apps. Also adds WASM/ESM integration support.
⭐ Astro 7.0 – The popular web framework gets faster build times, with .astro compilation and Markdown/MDX processing going through a Rust-powered pipeline. Advanced Routing also gives you full control over the request pipeline.
pnpm 11.7 and 11.8 – pnpm install gets a --dry-run option, --frozen-store adds support for read-only package stores, and more.
Node.js v26.3.1 (Current), v24.17.0 (LTS), and v22.23.0 (LTS)

📖 Articles and Videos

How an Underrated Refactor Saved 90% Memory Usage — The tale of how TanStack Table v9 uses less memory than v8 on large tables, thanks to a simple idea: storing methods on shared prototypes instead of creating them for every object. Benchmarks included, plus a pattern other libraries can copy.

Kevin Van Cott (TanStack)

You Already Know Enough JavaScript to Ship a Real Mobile App — Build for iOS and Android from one codebase with React. Expo handles builds, the App Store, and updates.

Expo sponsor

📄 window.showDirectoryPicker Opens Up a Whole New World – Chrome 86+ added a way to let users open a local directory for use by webapps. Steve Harrison

📄 What are Git Worktrees, And Why Should I Use Them? – A decade-old git feature that's seen a boost in the AI agent era. Cassidy Williams (GitHub)

📄 TanStack Start: A Mental Model for Next.js Devs – Maps TanStack Start onto Next.js concepts with side-by-side code comparisons. Adarsha Acharya

🛠 Code & Tools

FullCalendar 7.0: A Full Sized JavaScript Calendar — A Google Calendar-style experience for your own apps. Works with React, Vue and Angular (v7.0 adds Angular 22 support), but can be used with plain JavaScript. Here’s a demo where you can play with the themes and styling approaches. MIT licensed with commercial extensions.

FullCalendar LLC

🤖 Eve: Like Next.js, But for Building Agents — A new framework from Vercel that provides Next.js-esque structure for building AI-powered agents using TypeScript and Markdown.

Vercel

Your Charts Endpoint Doesn't Need a Second Database — It's the query behind it, not the render. TimescaleDB extends Postgres for analytics. Get $1000 credit to start.

Tiger Data (creators of TimescaleDB) sponsor

ForesightJS 4: Predictive User Intent Library for the Web — Predicts intent from pointer and keyboard cues to prefetch content before it's needed for a snappier user experience. v4.0 adds official React and Vue packages with a declarative <Foresight> component in v4.2.

ForesightJS, Inc.

Prop For That: What JS Knows, Now CSS Knows — Provides CSS with access to values you'd often need JS to provide (e.g. pointer position, time, a slider’s value). Add attributes to HTML and live values show up as custom properties, bridging the JS–CSS gap. The demo page is neat.

Adam Argyle

Kage: Shadow a Website for Offline Viewing — A tool to clone a site and serve it up for offline viewing. The difference vs "Save As" is it handles JS-rendered sites by saving the DOM using a headless browser. Repo.

Duc-Tam Nguyen

goja: An ECMAScript/JavaScript Engine in Pure Go — A mature JavaScript engine for adding scripting functionality to Go apps without CGo/V8.

Dmitry Panov

Anime.js 4.5 – The powerful animation engine adds adapters to support animating non-DOM objects like Three.js meshes or a canvas context.
Ink 7.1 – The popular TUI renderer adds suspendTerminal() for temporarily handing the terminal over to a child process (like an editor).
Nuxt UI 4.9 – The Vue UI library improves its calendar component, adds uniform focus styles, and adds useTour for driving guided tours.
Nx 23.0 – The monorepo tool's yearly major. Now nx migrate can hand migrations off to AI agents.
☀️ SunCalc 2.0 – Calculate the position and phase of the Sun and Moon.

📰 Classifieds

Flaky tests slowing down dev? Meticulous gives engineers confidence to ship faster by autonomously testing every edge case of your web app.

🚀 Take your app from dev to production in one command. clerk deploy handles DNS and OAuth: clerk.com/changelog/2026-06-10-clerk-deploy

Handsontable: Production-ready data grid that feels like Excel. Rock-solid reliability, performance at scale. Try now.

🦊 Extract tables, text, forms, and images from any PDF as structured JSON. Foxit's API combines OCR, layout recognition, and AI parsing.

📢 Elsewhere in the ecosystem

A developer code-golfed a signal implementation to just 33 bytes (above). I had to stare at it for a solid minute before it clicked, but mercifully, a Redditor breaks down exactly what's going on.
🔒 GitHub has released actions/checkout v7 that "refuses common pwn request patterns by default" including refusing to fetch fork pull request code in pull_request_target and workflow_run workflows.
If you're a GitHub project maintainer getting flooded with PRs, GitHub now has the ability to limit the number of PRs any single user can open at once.
Tim Wehrle stored a website in a favicon. Why? Why not?

Flow vs TypeScript in 2026

Tue, 16 Jun 2026 00:00:00 +0000

#790 — June 16, 2026

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JavaScript Weekly

Flow for TypeScript Users in 2026 — Flow is Meta's mature typed dialect of JavaScript, and over the years its syntax has converged closely with TypeScript's. This post walks through where the two now differ: Flow's stricter defaults reject several crash-prone patterns TypeScript's strict mode accepts, and it adds features of its own, like exhaustive match expressions.

George Zahariev (Meta)

Free Claude Code Course from Anthropic + Master.Dev — Coding is changing fast, and the engineers who thrive will be the ones who direct AI instead of guessing at it. Lydia Hallie from Anthropic teaches exactly that in our Claude Code course, now free for everyone.

Master.dev sponsor

npm v12 to Stop Running Install Scripts by Default — The forthcoming npm v12 will no longer execute preinstall/install/postinstall scripts, unless you explicitly allow them. You can get ready now by using npm 11.16.0 which prints warnings about anything v12 would block.

GitHub

🤖 Code is Cheap(er) — The creator of htmx says that while code is increasingly easy to produce, understanding is still expensive, and “complexity remains our apex predator.”

Carson Gross

IN BRIEF:

The pnpm team has created a new GitHub Action to set up both pnpm and a JS runtime (Node, Deno, or Bun).
🐈 Compilecat (repo) is a new, experimental JavaScript performance compiler that does Closure-style optimizations.
Several major projects are taking shape in beta/pre-release stages right now, including SvelteKit 3.0, Vue 3.6, Vite 8.1, and Astro 7.0.

RELEASES:

Playwright 1.61 – You can now register and test passkeys, as well as read/write to localStorage and sessionStorage via a new WebStorage API.
ESLint v10.5.0 – Five core rules now highlight smaller ranges of code to avoid shadowing other problems in editors.
🤖 TanStack AI Beta – Framework and provider-agnostic AI toolkit.

📖 Articles and Videos

How TanStack Cut TypeScript Type-Checking Work by Up to 86% — TanStack Table v9 (now in beta) made its features modular, but the generic types behind that flexibility introduced noticeable editor lag in alpha. This deep-dive shows how the team used tsc diagnostics to cut type-checking work by 62–86%, with lessons for anyone authoring type-heavy libraries.

Kevin Van Cott (TanStack)

🛠️ React Libraries and Tools for 2026 — Every year, Robin updates this post covering his opinionated list of essential React ecosystem libraries.

Robin Wieruch

Your AI Writes Tests That Pass but Prove Nothing. Fix It — Wallaby CLI makes test generation 10x smarter with live coverage and runtime data, using 3x fewer tokens. One skill to install.

Wallaby Team sponsor

Changing the Kindle's Homepage by Editing Hermes Bytecode — The Kindle’s UI now runs on a Hermes-powered JavaScript stack. Here’s how you can edit the bytecode Hermes produces to change the Kindle UI’s behavior.

Nicholas Tarta

📈 Making numpy-ts as Fast as Native — How a TypeScript NumPy port went from 15x slower to matching native, by changing not whether to use WASM, but who owns the bytes.

Nico Dupont

📄 How Building an HTML-First Site Doubled Our Users Overnight – Out with the React, and in with the Astro. Alistair Davidson

📄 Building a Real Blog Easily in Astro – By real, Zell means something beyond demo-level, with excerpts, post update dates, etc. Zell Liew

📄 Streaming HTML with textStream() in Chrome Canary Ollie Williams

🛠 Code & Tools

eslint-plugin-unicorn 67.0: More Than 200 Powerful ESLint Rules — Sindre’s set of curated rules has grown a lot, with almost 100 added or updated in the past few weeks alone. Like enforcing better comments, limiting the depth of nested calls, preferring Temporal over Date, and preferring HTTPS over HTTP in URLs. These rules will seriously challenge (and improve!) your code.

Sindre Sorhus et al.

zod-compiler: Compile Zod Schemas into Zero-Overhead Validators — A build-time compiler that plugs into Vite, webpack, et al. and rewrites existing schemas into optimized, tree-shakeable validators. Claims 2–75x faster validation with no source changes and the full Zod API preserved.

Gajus Kuizinas

That Slow Analytics Endpoint? It's a Database Problem — Pipelines, sync lag, stale data. That's the cost of a split stack. TimescaleDB extends Postgres so your app stays fast.

Tiger Data (creators of TimescaleDB) sponsor

📊 billboard.js 4.0: A JavaScript Chart Library Based on D3 — At almost nine years old, billboard.js now has a new, opt-in canvas-based rendering mode (SVG remains the default), smaller bundles, and better performance on large datasets. There are hundreds of demos ranging from donut charts and funnel charts to overlapping bar charts and radar charts.

Jae Sung Park (NAVER)

PolyCSS: CSS 3D Engine for the DOM — Renders textured 3D polygon meshes entirely in the DOM using CSS matrix3d() transforms — no WebGL or <canvas> required. Works with vanilla JS, React, and Vue. There’s a gallery to explore and a live builder if you want to play around.

LayoutitStudio

Tabulator 6.5 (above) – Create interactive tables from any HTML table, JS array or JSON data.
🕒 <relative-time> 5.2.0 – Web Component for formatting automatically-updating timestamps as localized strings or relative times.
Fable 5.2 – No, not the LLM you can't use, but an F# to JS/TS (and now Erlang too) compiler you can use. More info.
React Native 0.86 – Edge-to-edge support on Android 15+ and improvements to its DevTools.
Biome 2.5 – The fast code formatting and linting toolchain has now passed 500 lint rules.
get-value 4.1 – Use paths like a.b.c to get a nested value from an object.
axios v1.18.0 – Promise-based HTTP client for the browser and Node.
📊 visx 4.0 – Airbnb's visualization primitives for React.

📰 Classifieds

📸 Add robust in-browser barcode scanning to your web apps using STRICH, a lean JS library. Free 30-day trial, try the demo app today!

Flaky tests slowing down dev? Meticulous gives engineers confidence to ship faster by autonomously testing every edge case of your web app.

🤖 Generate 50,000 invoices overnight. Foxit's DocGen API merges JSON data into branded PDFs at scale, with no PDFKit and no copy-paste.

📢 Elsewhere in the ecosystem

🌐 The WebKit team shows off MapKit JS 6 (above), a way to integrate Apple Maps into your site like in this example. You need a token from an Apple Developer account though.
😱 A developer was sent a malicious JavaScript 'coding test' by a fake recruiter on LinkedIn in an attempt to backdoor his machine. I've heard about this vector a few times this year, so be careful.
WASI 0.3 (WebAssembly System Interface) has launched, bringing native async support to WebAssembly Components.
performative-ui is a fun set of modern clichéd "AI startup" UI components for React, like ASCII hero art and node graph backgrounds.
A dev had an old USB scanner with no modern drivers, but got it working via a browser-based WASM-powered emulator bridged to the physical scanner through WebUSB. He previously did something similar with an old printer.