This tool reads type definitions files written for TypeScript (.d.ts files) and rewrites them to .scala files usable with Scala.js.
The process is not 100 % accurate, so manual editing is often needed afterwards. This can be improved, but not to perfection, because the features offered by the type systems of TypeScript and Scala.js differ in some subtle ways.
$ sbt 'run somelib.d.ts SomeLib.scala'
The TypeScript Importer for Scala.js is distributed under the Scala License.