$ firebase emulators:start
i  emulators: Starting emulators: functions
⚠  functions: The following emulators are not running, calls to these services from the Functions emulator will affect production: auth, firestore, database, hosting, pubsub
⚠  Your requested "node" version "12" doesn't match your global version "10"
i  ui: Emulator UI logging to ui-debug.log
i  functions: Watching "/private/var/folders/xl/6lkrzp7j07581mw8_4dlt3b000643s/T/tmp.4l0amrGc/functions" for Cloud Functions...
✔  functions[functions-helloWorld]: http function initialized (http://localhost:5001/fir-dumpster/us-central1/functions-helloWorld).

┌─────────────────────────────────────────────────────────────┐
│ ✔  All emulators ready! It is now safe to connect your app. │
│ i  View Emulator UI at http://localhost:4000                │
└─────────────────────────────────────────────────────────────┘

┌───────────┬────────────────┬─────────────────────────────────┐
│ Emulator  │ Host:Port      │ View in Emulator UI             │
├───────────┼────────────────┼─────────────────────────────────┤
│ Functions │ localhost:5001 │ http://localhost:4000/functions │
└───────────┴────────────────┴─────────────────────────────────┘
  Emulator Hub running at localhost:4400
  Other reserved ports: 4500

$ http http://localhost:5001/fir-dumpster/us-central1/functions-helloWorld
HTTP/1.1 200 OK
connection: keep-alive
content-length: 20
content-type: text/html; charset=utf-8
date: Mon, 28 Dec 2020 15:50:38 GMT
etag: W/"14-z3iZXchEt5DVWZKsMncy8Wl4KSQ"
x-powered-by: Express

Hello from Firebase!

$ http http://localhost:5001/fir-dumpster/us-central1/functions.helloWorld
HTTP/1.1 404 Not Found
Connection: keep-alive
Content-Length: 86
Content-Type: text/html; charset=utf-8
Date: Mon, 28 Dec 2020 15:50:58 GMT
ETag: W/"56-o2lBSK2ZagofGuWRTO91r8ShW5M"
X-Powered-By: Express

Function functions.helloWorld does not exist, valid triggers are: functions-helloWorld