Announcing TypeScript 5.9
If you’re not familiar with TypeScript, it’s a language that builds on JavaScript by adding syntax for types. With types, TypeScript makes it possible to check your code to avoid bugs ahead of time. The TypeScript type-checker does all this, and is also the foundation of great tooling in your editor and elsewhere, making coding even easier. If you’ve written JavaScript in editors like Visual Studio and VS Code, TypeScript even powers features you might already be using like completions, go-to-definition, and more. You can learn more about TypeScript at our website.
A few fixes for reported issues have been made since the 5.9 beta, including the restoration of AbortSignal.abort() to the DOM library. Additionally, we have added a section about Notable Behavioral Changes.
For a while, the TypeScript compiler has supported an --init flag that can create a tsconfig.json within the current directory. In the last few years, running tsc --init created a very “full” tsconfig.json, filled with commented-out settings and their descriptions. We designed this with the intent of making options discoverable and easy to toggle.
