Maintaining a dependency on a library should be much less effort than maintaining 17 lines of code. If it isn't that's a deficiency in your dependency infrastructure.
If you have 100 dependencies, then that's a 100 projects you need to follow and understand the updates for. The minute your dependencies bring in their own dependencies then you start having troubles keep up or even keeping track of the updates. The 17 lines of code you pull in is in most cases a one time deal, having it in a third party library means that you need to keep track of that library for ever.
Honestly, and this is maybe just me being biased against JavaScript, then this is what happens when you pick a language fully knowing it's limited in all sort of silly ways and attempt to use it as a general purpose language. It's not that you can't, but if you need say typing that can tell you if something is an array, then maybe picking JavaScript to begin with wasn't the brightest idea.
There's a ton of libraries and hacks out there, all attempting to fix the fact that JavaScript isn't really good general purpose language. ES6 is fixing a lot of these thing, but it's a little late in the game.
