Javascript substack module pattern

Sup!?

So, we are using React to get a photo, send to an API and convert the response into a chart with ChartJS.

Our first attempt involved writing a DataConverter class like this:

This is nice but... we have a class (ECMAScript 2015 https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes) which has no state at all, wouldn't be better to have a module instead?

Cool uh?!
Hang on!
Take a look at the return call: when this module is called, it is not offering a series of methods.
It is returning a function instead, so this module can be called as a function:

This is nice but apparently the power of NodeJS let's us build more robust code, using the substack module pattern:

Using this pattern we don't have to use the weird module pattern syntax, the code is more elegant and clear... agree???
One catch though, is where this code will be executed: server side or client side with build tools is fine, other cases there is a chance that all this function will be available in the global scope.

This pattern has also ways to expand the behaviour of our modules: