TypeScript 5.9
9 months ago
- #JavaScript
- #Programming
- #TypeScript
- TypeScript 5.9 has been released, introducing several new features and optimizations.
- New features include support for `import defer` syntax, `--module node20`, and summary descriptions in DOM APIs.
- Enhancements to developer experience include expandable hovers (preview) and configurable maximum hover length.
- Performance optimizations include caching instantiations on mappers and avoiding closure creation in file existence checks.
- Notable behavioral changes involve `lib.d.ts` updates and type argument inference adjustments.
- TypeScript 6.0 is planned as a transition point towards TypeScript 7.0, focusing on readiness for future updates.