Export javascript function from Wordpress plugin and import it in app.js?

Question

I'm writing a WP Plugin for my team to allow us to initialize GravityForms and handle form submissions from the client side. I have a function , initGravityForms() in the plugin's main.js that I want to be able to call from app.js, and I would prefer to have it as a module import so that I can force type and shape of the parameters that are passed to the function. Is there any way to accomplish this? Thanks.