Category: Java Script

ES2024 (ECMAScript 2024) ships three utility methods that each solve a common boilerplate pattern: Object.groupBy() replaces Array.reduce()-based grouping, Promise.withResolvers() replaces the resolver-capture pattern, and Array.fromAsync() replaces manual async iterator consumption. All three are baseline in Chrome 117+, Firefox 119+, and Safari 17.2+.

Module Federation (Webpack 5) allows JavaScript modules to be loaded from a remote URL at runtime — meaning one WordPress plugin can expose a React component, utility library, or data store, and another plugin can consume it without bundling a copy. This solves the classic WordPress “multiple jQuery / multiple React” problem for plugin ecosystems…

The TC39 AsyncContext proposal (Stage 3) solves a longstanding problem in JavaScript: how to propagate contextual information — request IDs, user sessions, performance timers — through asynchronous call chains without threading it manually through every function parameter. AsyncContext.Variable works like a thread-local variable in other languages, automatically propagating its value through await, Promise.then(), setTimeout, and…

ES2025 finalises the Explicit Resource Management proposal — the using declaration and Symbol.dispose / Symbol.asyncDispose protocol. using works like a try/finally block but at the variable declaration level: when the variable goes out of scope (or an exception is thrown), the object’s [Symbol.dispose]() method is called automatically. This eliminates entire classes of resource-leak bugs in…

The TC39 Observable proposal (Stage 2) brings a standardised reactive event-stream primitive to the browser — similar to RxJS Observable but built into the platform. The DOM is also gaining a EventTarget.prototype.on() method that returns an Observable, replacing the common pattern of converting DOM events to streams with external libraries. You can experiment today with…

The Web Animations API (WAAPI) brings CSS keyframe animation power to JavaScript: you can create, pause, reverse, and sequence animations entirely in script without managing CSS class names or listening for transitionend events. It is now baseline across all browsers and is the foundation that Framer Motion and GreenSock use under the hood.

The TC39 Signals proposal (Stage 1 as of 2025) brings a standardised reactive primitive to JavaScript — the same mental model behind Angular signals, Preact signals, Solid.js, and Vue’s reactivity system. A Signal holds a value; any computation that reads it is automatically re-run when the value changes. The @tc39/signal-polyfill package lets you experiment with…

ES2025 finalises a long-awaited addition to the Set prototype: seven new methods — union(), intersection(), difference(), symmetricDifference(), isSubsetOf(), isSupersetOf(), and isDisjointFrom(). All are available in Chrome 122+, Firefox 127+, and Safari 17+ without any polyfill. They replace verbose reduce/filter patterns and work on any Set-like object (anything with size, has(), and keys()).

The TC39 Pattern Matching proposal (Stage 2 as of 2025) introduces a match expression to JavaScript that is far more powerful than switch: it supports destructuring, guard clauses, binding, and checks against both value and shape. You can experiment with it today using the @babel/plugin-proposal-pattern-matching Babel plugin.