satisfies operator

DaTaobao Tech

Oct 17, 2022 · Frontend Development

New Features in TypeScript 4.9 Beta

The TypeScript 4.9 beta, released on September 23 2022 and installable via npm or the VS Code Nightly extension, introduces a new satisfies operator, upcoming --noImplicitSuffix option, per‑file @ts‑* directives, refined in operator narrowing, NaN equality warnings, an updated Promise.resolve signature, and preserves import statements in JavaScript files, while postponing full decorator support to version 5.0.

4.9DecoratorsModuleResolution

0 likes · 15 min read

Taobao Frontend Technology

Sep 27, 2022 · Fundamentals

What’s New in TypeScript 4.9 Beta? New Decorators, satisfies Operator, and More

TypeScript 4.9 beta introduces ECMAScript‑aligned decorators, a new satisfies operator for safer upcasting, support for .ts import extensions, per‑file tsconfig directives, enhanced in‑operator narrowing, NaN equality warnings, updated Promise.resolve typing, and full retention of JavaScript imports, with installation instructions and migration notes.

BetaDecoratorsTypeScript

0 likes · 16 min read

What’s New in TypeScript 4.9 Beta? New Decorators, satisfies Operator, and More