Besides support for nullable types, a beta of TypeScript 2.0 is now available that includes a smoother way of working with declaration files and makes module declarations more efficient.

TypeScript 5.5 also adds a t ranspileDeclaration API, which is designed to generate a single declaration file based on input source text. The API is similar to transpileModule for compiling a ...

Among other things, you’ll need to change module-based require() or define() statements to TypeScript import statements and add declaration files for any library modules you use.