tsconfig.json
======================

{
  "files": [
    "hello.ts"
  ],
  "compilerOptions": {
    "moduleResolution": "node"
  }
}

package.json
=====================

{
  "name": "sandbox",
  "version": "0.0.0",
  "description": "Sandbox",
  "main": "app.js",
  "author": {
    "name": "0xCDCDCDCD"
  },
  "dependencies": {
    "@types/node": "^9.4.5"
  }
}

app.json
=====================
'use strict';
var hello = require('./hello');
//import { hello } from 'hello';

var world = new hello();



hello.js
======================

'use strict';

var stream = require('stream');
var fs = require('fs');

//import { stream } from 'fs';
//import { fs } from 'fs';

export class hello {
    world(): stream.Readable {
        return fs.createReadStream('app.js');
    }
}