How to stop Laravel Mix breaking my JS file that contains jquery libraries?

Hi all I have a really simple newbies question. I've just started using Laravel Mix, which seems great in general.

This in progress project I have currently contains a single Js file, which is a mixture of my own functions and a few jQuery libraries pasted one after the other. This worked fine until I start using Mix.

It seems that some of the JS libraries I was manually compilin ginto my master JS file manually don't play well with mix/jetpack.

If this is the case, I want to confirm, what is the best way of just appending js libraries without them being recompiled or altered during the merging process with my other JS?

Currently I'm using require("jquery-library/src/filename.js");

Is that the best approach ?