Firestore emulator: Error: 14 UNAVAILABLE

Firebase CLI 7.10.0 Firestore emulator 1.10.2

index.js:

const functions = require ('firebase-functions');
const admin = require ('firebase-admin');
admin.initializeApp();
const firestore = admin.firestore();

exports.helloWorld = functions.https.onRequest (async (req, res) => {
  const docRef = firestore.collection ('col').doc ('doc');
  await docRef.set ({foo: 'bar'});
  const docSnap = await docRef.get();
  const wroteCorrectly = docSnap.get ('foo') == 'bar';
  res.send (wroteCorrectly ? 'Worked' : 'Did not work');
});

Expected: ‘Worked’. Instead: Error: 14 UNAVAILABLE: No connection established (etc.)

• FIRESTORE_EMULATOR_PORT is set (8080).
• GOOGLE_APPLICATION_CREDENTIALS are set.
• This runs fine on the remote Firestore. Only a problem when using local emulator.

[samtstern]

@bwhrsc thanks for your feedback, it shows that some things are not documented as clearly as they could be.

FIRESTORE_EMULATOR_HOST is an environment variable you can set to tell Firebase SDKs to talk to the emulator rather than to production. It does not control where the emulator runs. To set that, you change a value in firebase.json:

{
  "emulators": {
     "firestore": { "port": 8080 }
  }
}

So when you want to run tests against the emulator you can use one of two methods.

Method 1: Manual In one terminal, run the emulators:

$ firebase emulators:start

In another terminal, run your tests and set the env var:

$ export FIRESTORE_EMULATOR_HOST="localhost:8080"
$ npm run test

Method 2: Automatic In your terminal, run:

$ firebase emulators:exec "npm run test"

The above command will do the following things, in order:

1. Start up all the emulators (and wait for them to confirm they are running)
2. Launch a new subprocess with the proper environment variables (FIRESTORE_EMULATOR_HOST, etc) setup
3. Run your test command (npm run test or anything else) in that subprocess
4. Wait for your test command to finish
5. Cleanly shut down all the emulators and exit

So I believe that should fix your issue. Let me know if something is still not working!

[mrspence]

Tip: Try removing the protocol from your hostname

i.e.:

functionsInstance.useEmulator(`http://${emulatorHostname}`, 5001)

becomes

functionsInstance.useEmulator(emulatorHostname, 5001)