disclaimer: I am not a lawyer.
In short, no. You're not required to share anything when you use or adapt CC content.
So, while you may share your final product, you aren't required to share the intermediate forms, including source code.
Quoting from the CC-BY-SA 4.0 license (paraphrased and emphasis added):
Section 3.a. (Attribution) says "If You Share ...
I believe requiring .js files is definitely a dynamic linking. It's not much different from linking a library in your project for the use of library's functionality, which would be considered using the library as a plugin by GPL:
Linking a GPL covered work statically or dynamically with other modules is making a combined work based on the GPL covered work....