Possibility of more robust emulator detection

[luc122c]

I was taking a look at the way Vuefire detects and connects to the Firebase emulators:

vuefire/packages/nuxt/src/module/emulators.ts

Line 55 in cab2e95

export function detectEmulators(

Currently, it uses a combination of environment variables and the firebase.json file to see which emulators should be enabled. However, I believe there is a better option. firebase.json and the env variables just tell the emulator suite the desired ports. While most of the services will shutdown if the port is unavailable, not all do:

⚠  logging: Logging Emulator unable to start on port 4500, starting on 4501 instead.

The firebase emulator hub offers a REST API to query the running emulators and get back the actual host and port in use. I think this would be a more robust solution.

We could simply fetch this endpoint, and capture the host and ports from it. A rough example below:

const emulators = await $fetch<FirebaseEmulatorConfig>(`http://${HOST}:4400/emulators`)
 
if (emulators.firestore) {
  const { host, port } = emulators.firestore;
  connectFirestoreEmulator(firestore, host, port);
}

if (emulators.auth) {
  const { host, port } = emulators.auth;
  connectAuthEmulator(auth, `http://${host}:${port}`);
}

I've been using this in my testing to connect to the emulators and it works fine. Just thought I'd post this idea to get your thoughts.

[posva]

This is a very good idea! Feel free to give it a shot as I have other things to focus on right now.

[luc122c]

I'll work on a PR for it. Just wanted to run it past you before making a start.