Scope is like oxygen to a programmer. It’s everywhere. You often don’t even think about it. But when it gets polluted . . . you choke.
The world of JavaScript development is changing frantically, and the part of the language that has undergone the most change is its module system.
In modern application development, we take the notion of modular programming for granted. The practice of breaking our applications into different files and then recombining them is already second nature to us. We don’t do these things to avoid getting blisters on our fingers from endless scrolling; we do them so that we can reason about and evolve different parts of our applications separately without fear of breaking others.