Welcome to the future with 50y old technology. There is an obscure emacs extension, swank js, that runs a nodejs daemon that speaks slime to emacs.
It allows you to work with js the same way you'd work with lisp, evaling lines or buffers into a live nodejs instance.
I use it (in combination with org-babel) to talk to live instances of remote services, to inspect data, experiment, but also as kind of an on-the-fly UI
It allows you to inject js into a browser as well, handy for js dev or even on the fly data scraping/web manipulation. Super useful yet not very well known.