> I don't put all of that into my CSV parser,

The art of not cluttering a library with too much stuff is a hard lesson to acquire. Most library authors try to throw in the kitchen sink. It's insane. I'm sure I was guilty of it in the past.

For parser take a string. let me do the I/O outside. If you want to offer streams then just offer an abstract interface stream and then a few examples of implementing a stream but don't include them in your library. It's just clutter.

This is one if largest problems with NPM. So many libraries try to do too much. Some come with a command line utility "just because"!??!?! It then adds more surface area, more dependencies, more churn as we have to update all those un-needed dependencies.