Webpack: Mix AMD and ES6 Modules

We are especially interested in what happens to contructor function, because we are stumbled on issues in a really large project with them. Contructor functions are suddenly objects if you do the following:

Module 1 (ES6) -> uses Module 2 (AMD) -> in which the class MyClass of Module 3 (ES6) is instantiated -> Error
    -> Uncaught TypeError: MyClass is not a constructor
    -> it is an object

Usage

1. npm install
2. npm run start
3. load index.html in browser

Former Console Output

Is is very unlikely: it works as expected! The current output in my browser console looks like this (Chrome 60, Linux):

Inside module2, what type is the exported constructor of module3? object Object
mix-bundle.js:89 Uncaught TypeError: Something is not a constructor
    at Object.<anonymous> (mix-bundle.js:89)
    at Object.defineProperty.value (mix-bundle.js:95)
    at __webpack_require__ (mix-bundle.js:20)
    at Object.<anonymous> (mix-bundle.js:72)
    at __webpack_require__ (mix-bundle.js:20)
    at Object.defineProperty.value (mix-bundle.js:63)
    at mix-bundle.js:66

SO-Question

There is this SO-Question, which describes at least a similar problem. I will now try to find a solution based on its answer and similar resources, although it is related to the usage of Babel.

Current Console Output

After fixing the bug by using Something.default in module2 the console output looks like this:

Inside module2, what type is the exported constructor of module3? object Object ƒ Something(){
    this.hello = 'Hello';
}
mix-bundle.js:90 check instance of something Hello June!
mix-bundle.js:78 Check anotherthing and whole chain: Hello Cathrine!

Solution

It is up to you, whether you want to use export default and the .default reference, just export or the (for me) opaque

export var __useDefault = true; // after export default

solution here.