https://github.com/azu/tsconfig-to-dual-package

This tool helps you to create Dual CommonJS/ES module packages. (dual package is a package that can be used from CommonJS and ESM)

It is hard to create dual package in only TypeScript Compiler(`tsc`) because TypeScript do not change import file path by their design goal. This tool create Dual Package by using some tricks in package.json without additional transpiling.