Espruino plugin for Rollup module bundler

Couldn't you automate detection of the Espruino so that the port doesn't have to be entered manually? Even just changing to a different USB port will cause this value to change. In the script that I wrote for this, I copied the code that the web IDE uses to identify Espruino boards and connect to the corresponding port:
https://github.com/stokebrain/morra-buil­d/blob/master/main.js#L23

Webpack also has tree-shaking. When I first tried rollup, I concluded it wasn't a good choice because I saw that it was placing top-level variables from all modules, all together in the same scope. I was too concerned about name collision and went back to webpack.

Also, I don't see the smaller footprint that rollup is claiming.
https://vkbansal.me/blog/rollup-first-im­pressions/

I continually see people writing that rollup configuration is easier, but that has not been true for me. Webpack just worked, and rollup continues to require debugging.

I still have some complaints and issues to solve with webpack. For my first project it all worked well, but in my current MQTT test, I'm getting errors when using my build-and-save script. One thing that concerns me is the use of arrays in the build, because I don't know if these will cause performance issues for Espruino.