Today, we’ve got some game-changing updates from Microsoft, the long-awaited Svelte 5 release, and the new Next.js 15 release—plus a whole lot more!

Microsoft GenAIScript

• Prompt as Code: Automate code summarization, error checking, and data parsing using minimal JavaScript or TypeScript syntax.

• LLM Tools & Agents: Define tools and agents like Git assistants or weather data fetchers that interact seamlessly with LLM models. By defining these agents, developers can create reusable components that provide intelligent suggestions or perform specific functions based on LLM prompts.

• File Manipulation: Extract, analyze, and manipulate data from PDFs, DOCX, CSVs, and more, making it ideal for data-heavy projects. Whether it’s converting a PDF to text or extracting tables from CSV files, developers can automate these tedious processes, which are often prone to errors when done manually.

• GitHub Integration & CI/CD Automation: With built-in support for GitHub Models and Copilot, as well as automated GitHub Actions, developers can leverage LLMs to handle pull request reviews, commit message generation, and even integrate into CI/CD pipelines.

Svelte 5 Is Finally Here

• Runes & Reactivity: Introduces "runes" for cleaner reactive state management, replacing the old $: construct. This change simplifies state handling by making dependencies more explicit, avoiding common pitfalls with the previous system.

• Native TypeScript: Full TypeScript support, no more preprocessors needed.

• Backward Compatibility: Svelte 5 offers a mostly seamless upgrade from Svelte 4, with migration tools for easy transition. This backward compatibility ensures that developers can migrate gradually, without having to rewrite their entire application from scratch. The migration tools automate much of the process, minimizing downtime.

• Improved Event Handling: Event handlers are now treated as props, making component composition more intuitive. This change allows developers to more easily manage event propagation and conditional handling, streamlining the creation of reusable components, especially for large applications and libraries.

Next.js 15: The Speed King

Next.js 15 has finally been released! This version focuses on improving both stability and speed.

Here’s all you need to know:

• @next/codemod CLI: Automates code upgrades, making it easier to update Next.js and React versions. With this tool, you can avoid manual refactoring when upgrading, ensuring your codebase stays clean and efficient.

• Turbopack Dev: Boosts development speed with up to 96% faster code updates. Turbopack is set to replace Webpack as the default bundler, offering blazing-fast rebuild times, especially in large projects.

• Static Route Indicators: New visual cues for static routes during development provide immediate feedback, helping you optimize performance for individual pages and track which routes are truly static for better caching and rendering.

• Automatic Image Optimization Enhancements: Image optimization is now built-in by default, removing the need for manual configuration. This means you get optimized images (including resizing, lazy loading, and WebP support) automatically, allowing developers to focus on building features rather than handling image performance.

Tools & Releases You Should Know About

Let’s speed-run through some of the other big tool updates this week!

• React Native 0.76: The new default architecture delivers smoother app performance, improved debugging, and smaller Android app sizes.

• Bun’s Latest Update: Experimental CSS parsing and bytecode compilation options boost development speed by 2x. Plus, bun publish makes npm package publishing a breeze.

• ExpressJS v5: After a decade of waiting, Express 5 is here with modernized security features, improved route patterns, and enhanced support for promises.

• Transformers.js v3: Running machine learning models in JavaScript just got faster thanks to WebGPU support. Now you can execute real-time tasks right in the browser!

• eslint-plugin-functional: This plugin enforces functional programming principles in JavaScript and TypeScript by blocking mutation and encouraging immutability, helping you write cleaner, more reliable code.

That’s a wrap for this week! If you found these JavaScript updates useful, give this post an upvote to help others discover it.

Don’t forget to share it with your fellow developers, and keep an eye out for more insights in the JavaScript world. Until next time, keep coding and stay curious!

References

Microsoft GenAIScript

Svelte 5 Update

Next.js 15

React Native 0.76

Bun v1.1.33

ExpressJS v5

Transformers.js v3

eslint-plugin-functional