Export interfaces for typescript library published at npm

Question

I'm writing a library with TypeScript to be used by both js and ts projects. I compile it and upload both the .js and .d.ts files to npm, my main.ts exports the following:

interface MyInterface{
// ...
}


class MyClass{
 public myMethod(): MyInterface { /* code */ }
}

export = new MyClass();

A js project can then install and import the library directly:

const myLib=require('my-lib');

myLib.myMethod(); // OK

A typescript project can also import the library:

import * as myLib from 'my-class';

myLib.myMethod(); // OK

However, I want to also export MyInterface for typescript projects so I can do the following in a project importing my library:

import {MyInterface} from 'my-lib';

function anotherFunction(arg: MyInterface){

}

I have no idea how should I export things in my main.ts so I can achieve something like this while keeping the same support for javascript-based projects.

Answer 1

Just export both interface and class,

// my-lib

export interface MyInterface{
// ...
}


export class MyClassStatic{
 // if your method not dealing with any context(this), you can decalre the method as 'static'
 public static myMethod(): MyInterface { /* code */ }
}

export class MyClass{
     public myMethod(): MyInterface { /* code */ }
}

In code,

import * as myLib from 'my-lib';

// accessing static method
myLib.MyClassStatic.myMethod();

// accessing class members 
const myClass = new myLib.MyClass();
myClass.myMethod();