It's interesting to me that everyone uses that isArrayish module example as though it represented the downfall of civilization when to me, yes maybe it represents the downfall of civilization a little bit, but it also represents the strength of npm. Absolutely anyone can create code, put it online and then have others use it fast. Of course this means you do end up with a lot of nonsense, but a lot of brilliance too.

Nobody does this with maven because maven and the Java community in general makes this hard. It's doable, but generally takes more work, which is a strength and a weakness for the Java community. You could argue this is "worse is better"[0], making sacrifices, in this case in redundancy for simplicity of use. People should really just write the code for isArrayish if it is this simple, or perhaps the language or babel or whatever should provide such a function.

However no one forces anyone to use these, if you want a standard library, use Lodash, here is its isArray: https://lodash.com/docs#isArray, it even has differentiations of this like: https://lodash.com/docs#isArrayLikeObject. Complaints about something like the isArrayish module make my head hurt. It filled a void fast where one existed so people could use it and get on with their projects and subsequently their lives. I just don't see anything wrong with that.

0) https://www.jwz.org/doc/worse-is-better.html