What do you do when you have an old school application where JavaScript is written in non-modern style? For example, you have a.js and b.js. You define a function "hello" in a.js and use it in b.js. In the project, the developer assumes that the two files will be included in correct order within HTML. Linters fail here because they think b.js uses an undefined function, when it's actually defined. Unfortunately, since most JS linters only validate one file at a time, they are pretty much useless here.