The future JavaScript features at TC39

August 26, 2022 By Mark Otto Off

If you missed my note two weeks ago, we took last week off, so you didn’t miss any issues 🙂 We’re now back every week until Christmas (121 sleeps to go..)
Peter Cooper, your editor.

When Alternative JS Runtimes Grow Up: Deno Has Big Changes Ahead, and the Creator of Bun Forms Oven

Two distinct stories that we felt deserved to be together as they provide a little look at the development of alternative server-side JavaScript runtimes that aren’t Node.js and are both going after overlapping markets.

Deno’s big news is that they’re working hard on npm compatibility and Deno will be able to use most npm modules soon (Deno 1.25 has been released with a preview). Meanwhile, Jarred Sumner, the creator of Bun, has answered our pun prayers and formed Oven, a company to support Bun’s development, and already raised $7m for it. The heat is, most certainly, on.



▶  On the Future Features of JS — Hemanth is a TC39 delegate and hosts the popular TC39er podcast. In this 25-minute talk, he flies through a variety of current language proposals, their progress, and why they matter.

Hemanth HM

Take a Tour of JavaScript & React Patterns — Join Lydia Hallie for the video course covering design patterns you can use to improve the code architecture of your web apps. Learn traditional JavaScript design patterns, React patterns, performance, and reading patterns.

Frontend Masters

TypeScript 4.8 Released — The typed superset of JavaScript continues to remain popular. 4.8 is more a minor evolution than a revolution, but makes improvements to inference, correctness and consistency, file watching, and serious speedups on rebuilds.

Daniel Rosenwasser (Microsoft)


  • 🛰 JavaScript is in space! The James Webb Space Telescope runs JavaScript onboard, though not in quite the same way as we all run it.

  • How do you pronounce JSON? Douglas Crockford, who basically came up with it in the first place, ▶️ explains all here. But what about tabs vs spaces..?

  • If you have any apps deployed on Heroku’s free tier, be aware of changes coming to Heroku in the next few months that may mean you need to migrate elsewhere. (Replit and are options we’re keen on.)

  • Node 18.8.0 is out and introduces easy support for creating and loading user-land snapshots.

  • PlanetScale, a serverless MySQL platform, has introduced an official serverless driver for JavaScript that’s Fetch API compatible.

  • Storybook 7.0 is now in alpha with some nice design changes.


Solid 1.5 – Declarative and flexible JS UI library.
Fiddle 0.30 – Electron playground tool.
Capacitor 4.1 – Cross-platform JS native app platform.
Note: There are more at the end of the issue.

📒 Articles & Tutorials

Understanding When and Why React Re-Renders — The processes around rendering are important to understand if you want to get the best performance possible from your React apps, so learn why and when React re-renders in the first place.

Josh W. Comeau

(Re-)Introducing Gatsby as a ‘Reactive Site Generator’? — Gatsby’s new focus is on enabling teams to deploy content rapidly with a new architecture that they say allows Gatsby Cloud to publish to its CDN in under a second. This post benchmarks Gatsby’s “Reactive Site Generation” (RSG) approach against most traditional approaches.

Kyle Mathews

🛠 Code & Tools

Node v16.17.0 (LTS) Released — A useful LTS release with a couple of modern backported features – this time, 16.x users gain access to the util.parseArgs CLI argument parsing function, the experimental ESM loader hooks API, and the node:test module and runner.

Michaël Zasso


Focus Trap 7.0 – Trap the focus within a DOM node (e.g. a modal).
Electron Packager 16.0 – Customize and package Electron apps.
DOMPurify 2.4 – Fast, tolerant XSS sanitizer for HTML and SVG.
vue-advanced-chat 2.0 – Agnostic chat room component.
Soketi 1.4 – Fast, resilient WebSocket server on Node.
Mineflayer 4.4 – API to create Minecraft bots.
calendar-base 2.0 – Base methods for generating calendars.

Find JavaScript Jobs with Hired — Create a profile on Hired to connect with hiring managers at growing startups and Fortune 500 companies. It’s free for job-seekers.

🥳 A Quick Bit of Fun

Head straight back to the 90s / early 00s and enjoy some retro Web cursor effects. Next up: custom scrollbars, 10px Tahoma, and scrolling frames everywhere.