It seems like whenever you run `functions-framework` locally, it deploys your function on localhost on a port of your choosing. This works great if you are developing a new function and just need to test it in a quick and easy way, but how are you supposed to write code that lets you easily develop and test multiple functions over time? I'm aware that firebase might solve that, but the reason I am asking this question is to understand what the state-of-the-art is outside of firebase.

The problem is, if I have code that hits my function URL, and then I want to update the function and test it as part of my application, it seems like I have to set a per-function environment variable that swaps out the HTTP trigger uri for the localhost:PORT testing URI. That's pretty annoying when you have to have a separate env variable for each function you might test.

Surely I'm missing something here? What do people do in this situation?

EDIT: Found this github issue (https://github.com/GoogleCloudPlatform/functions-framework-nodejs/issues/23) that seems to indicate that there's no equivalent solution to firebase/the old functions emulator for serving multiple functions locally, but you can fairly easily work around it by writing a little bit of code to multiplex your functions manually. I wish this was included in the official docs rather than just in the Github Issue!