~javascriptweekly | Issue 725 - Doom for TypeScript types (11)

Developer Implements 'Doom' in TypeScript's Type System — A curious quirk of TypeScript’s type system is that it is Turing-complete which has led some developers to implement apps entirely in the type system. One such developer has spent eighteen months producing 177 terabytes of types to get 1993’s Doom running with them. Ridiculous and amazing in equal measure, he ▶️ explains the project in this...

Functional JavaScript First Steps, v2 — A friendly, practical introduction to functional programming fundamentals in JavaScript. Learn the power of the pure function while exploring functional programming paradigms.

Bun v1.2.3 and v1.2.4 Released — The rapid pace of progress on the JavaScriptCore-based runtime is only increasing. v1.2.3 pushes frontend dev server features (run bun ./index.html and all the bundling is done for you). bun init can now be used to create a new React project. Meanwhile, Bun 1.2.4 builds macOS apps 60% faster and macOS executables can now be code signed.

What is TypeScript? An Overview for JavaScript Programmers — You may have noticed esteemed JavaScript developer and author Dr. Axel has been on a TypeScript odyssey recently. Here he does a good job at boiling down the what (rather than the ‘why’) of TypeScript. A handy primer on what’s going on, even if you don’t plan to use it, since you'll end up interacting...

React Libraries for 2025 — Each year, prolific React blogger Robin updates his post covering his opinionated list of essential React ecosystem libraries. He covers a lot of angles from project creation and package management through to state management, animation, form creation, auth, and i18n.

Turbocharging V8 with Mutable Heap Numbers — The V8 team uses the JetStream2 benchmark suite to investigate performance issues and has implemented a new optimization yielding not just a 2.5x improvement in the async-fs benchmark but in other areas too.

Subverting Control with Weak References — A weak reference differs from a normal reference in that it doesn’t prevent a referenced object from being garbage collected. Most modern JS runtimes support them and James shows how they can be useful.

Svelvet 11: Build Node-Based UIs with Svelte — A mature Svelte component library for creating interactive node-based UIs and diagrams. v11 adds the ability to toggle between ‘snap grid’ and freeform modes for manipulating elements. (There’s a live demo at the bottom of the homepage.)

React Native 0.78 Released — A big release for React Native as it ships React 19 support (which requires some tweaks when upgrading) and some more minor tweaks.

Random: Seedable Random Number Generator — You’ve got Math.random but this library takes things a few steps further with easy ways to create random values of various types and using different distributions (e.g. normal distribution, Bernoulli, Poisson, Pareto and Weibull).

QuickJS Sandbox 2.0: Execute JS/TS in a QuickJS Powered Sandbox — QuickJS is a small, embeddable JavaScript engine built by Fabrice Bellard and this extends it to make it easy to run code in an isolated sandboxed environment, along with some basic Node module support and a virtual file system. GitHub repo.