如何在 TypeScript 中导入和导出命名空间、接口和类型？ 从索引文件？

Question

I want to declare a module and define its Types and Interfaces without repeat my self - so I can define a type and if it is something that can be shared, to use it again from elsewhere.

So if for example I have a module called: User, I want to define a namespace called User and under it to define an Interface called Address and under Address to define one or more Types.

Now, Address Type is something that I probably going to use in other modules - not specific to User, but also to Order for example.

So I thought about creating a Interface directory and in this directory to add some files, each file per Interface and import all of those Interfaces to an index.ts file so it can be imported from anywhere of the app - actually even from other packages and modules and services that are not from within the same app.

For example:

Interfaces
  Address.ts
  Contact.ts
  Role.ts
  index.ts

// index.ts

import Address from './Address'
import Contact from './Contact'
...etc

export default { Address, Contact }

But this won't work. Because TS only help to write code, it won't add actual modules to the code and export it the way I mentioned above is meant for actual modules, not just Types and Interfaces!

So how can I export and import TS objects (Types, Interfaces, Namespaces, etc)?

What is the best practice? can you please provide a demo structure of it?

Answer 1

Something like this...

I made aCode Sandbox here which just prints some data to the console to prove type imports are working. This is based on having a types.ts file with types in, and importing them from there into an index.ts so you can indeed import types from another file in Typescript.