Today we are excited to announce the availability of TypeScript 4.9! If you’re not familiar with TypeScript, it’s a language that builds on JavaScript by adding types and type-checking. Types can describe things like the shapes of our objects, how functions can be called,

Here’s a quick list of what’s new in TypeScript 4.9!

  • The satisfies Operator
  • Unlisted Property Narrowing with the in Operator
  • Auto-Accessors in Classes
  • Checks For Equality on NaN
  • File-Watching Now Uses File System Events
  • “Remove Unused Imports” and “Sort Imports” Commands for Editors
  • Go-to-Definition on return Keywords
  • Performance Improvements
  • Correctness Fixes and Breaking Changes