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.