Java Script - You Need a Bundler

If you're writing anything beyond super trivial code, then you need to be writing tests. In order to write tests in JavaScript, you probably are going to use a testing framework. bundler is one of those things that you don't really need to know, you just need to be able to use it. It's kind of mandatory for now, but it's not something like, you know, deep knowledge. Anybody disagrees?