Class article MUST READ

[mhulse]

Avoid exporting your class. Use class internally for performance gains, but export a factory that creates instances in order to discourage users from extending your class and avoid forcing callers to use new.

https://medium.com/javascript-scene/why-composition-is-harder-with-classes-c3e627dcd0aa

The above seems to argue that factory functions are preferable over exporting a class from a module.