Indeterminate Behavior: Initializing Firebase for Emulator Suite

[hazel-sudz]

[REQUIRED] Describe your environment

• Operating System version: windows@latest
• Browser version: chrome@latest
• Firebase SDK version: firebase@latest (^8.5.0)
• Firebase Product: firestore/auth (auth, database, storage, etc)

[REQUIRED] Describe the problem

{code: "auth/invalid-api-key", message: "Your API key is invalid, please check you have copied it correctly.", a: null}

Steps to reproduce:

Using the documentation at https://firebase.google.com/docs/emulator-suite/connect_and_prototype the code snippett says:

// Firebase previously initialized using firebase.initializeApp().

However, it is unclear how one should call initializeApp(). Using the example linked in https://www.youtube.com/watch?v=pkgvFNPdiEs&t=314s, the firebaseConfig:

{
"databaseURL": "http://localhost:9000?ns={my project name here}"
}

produces the following error:
{code: "auth/invalid-api-key", message: "Your API key is invalid, please check you have copied it correctly.", a: null}

However, the firebaseConfig (project name substituted in):

{
   "apiKey": "this-does-not-matter-but-it-crashes-without-it",
   "projectId": "mock-firebase-backend",
}

Works just fine with no errors. I have confirmed this by sending reads and writes to the emulator without errors:

Am I missing something, or did the behaviour break between when the video was released and the current package version on npm?

Relevant Code:

Shown above

[looptheloop88]

Hi @daniel-sudz, you can use useEmulator() instead of changing the databaseURL property in the configuration object.

import firebase from 'firebase/app';
import 'firebase/database'

const config = {
    apiKey: "...",
    authDomain: "...",
    databaseURL: "...",
    projectId: "...",
    storageBucket: "...",
    messagingSenderId: "...",
    appId: "...",
    measurementId: "..."
};

firebase.initializeApp(config);

const database = firebase.database();
database.useEmulator("localhost", 9000);

[hazel-sudz]

@looptheloop88 I am aware of the useEmulator() -- I use it myself -- but what is potentially confusing to users of the emulator though is that apiKey property in the config is not actually needed for the emulator and yet it crashes without it. Ie. you have to set it to some string for initializeApp not to fail.

Is this expected behaviour? If so, could there be a PR upstream to clarify this in the documentation?

[looptheloop88]

@daniel-sudz, I wasn't able to reproduce the error. Using just the projectId property in the configuration worked fine. Please make sure that the Firebase Tools version that you're using is updated.

[vamsiampolu]

I have the same error reported by @daniel-sudz , despite providing an API Key. I started firebase emulators for auth and firestore, the environment looks like this:

Environment:
Node: lts/fermium
typescript: 4.2.4
jest: 26.6.3

"firebase-admin": "^9.7.0"
"firebase": "^8.6.2",
"firebase-tools": "^9.10.2",
@firebase/rules-unit-testing": "^1.3.2"

Error:

 {
      code: 'auth/invalid-api-key',
      message: 'Your API key is invalid, please check you have copied it correctly.',
      a: null
}

Code:

export async function createJwtToken(
  uid: string,
  email: string,
  databaseName = 'users',
  projectId = 'tellyhealth'
): Promise<string | undefined> {
  const hub = {
    host: 'localhost',
    port: 4400
  }

  firebaseTest.useEmulators({
    ...emulatorConfig.emulators,
    hub
  })

  const apiKey = process.env.FIREBASE_API_KEY
  console.log(apiKey)

  const app = firebaseTest.initializeTestApp({
    auth: {
      uid,
      email
    },
    projectId,
    databaseName,
    apiKey: process.env.FIREBASE_API_KEY
  } as any)

  console.log('Test App', app) // the test app is created.
  let testAuth = null

  try {
    testAuth = app.auth() // this line fails
    console.log('Test Auth', testAuth)
  } catch (e) {
    console.error(e)
  }

  if (!testAuth?.currentUser) {
    return undefined
  }
  return await testAuth.currentUser.getIdToken()
}

This error occurs even when using a databaseUrl. Please provide a working example of how a backend service can use @firebase/rules-unit-testing to initalise an app and retrieve a token?

[hazel-sudz]

@vamsiampolu just curious, could try updating firebase-tools to latest? I currently can't check but I set up a brand new project with latest sdks (but maybe not the tools) and am still seeing the problem

[vamsiampolu]

@daniel-sudz I updated from 9.10.2 to 9.11.0 which is the latest published version on npm. I restarted my emulators to be greeted once more with:

t {
      code: 'auth/invalid-api-key',
      message: 'Your API key is invalid, please check you have copied it correctly.',
      a: null
    }

I must point out that I have provided an apiKey despite it not being a part of the type in the testing library. @looptheloop88 any suggestions?

When I tried doing this instead:

async function createJwtToken({ email, password, projectId }) {
  const app = firebase.initializeApp({
    apiKey: 'gibberish',
    projectId,
    databaseName: 'default',
    databaseUrl: `http://localhost:9000?ns=${projectId}`,
    appId: 'fake-app',
    storageBucket: 'no-storage-bucket',
    authDomain: 'auth.foobar.com'
  })

  const authEmulatorHost = process.env.FIREBASE_AUTH_EMULATOR_HOST as string

  const auth = app.auth()
  console.log('auth emulator', process.env.FIREBASE_AUTH_EMULATOR_HOST)
  auth.useEmulator(`http://${authEmulatorHost}`)

  const creds = await auth.signInWithEmailAndPassword(email, password)

  if (!creds || !creds.user) return null

  const idToken = await creds.user.getIdToken()
  return idToken
  
}

This gives me the error:

 WARNING: You are using the Auth Emulator, which is intended for local testing only.  Do not use with production credentials.

I have also tried using the admin-sdk to generate a custom token:

process.env.GCLOUD_PROJECT = 'myProject'; //assume that the admin-sdk and the firebase emulators are using this projectId

async function createJwtToken(uid: string) {
   return firebaseAdmin.auth().createCustomToken(uid, {})
}

When I attempt to verify it, I provide the isEmulator flag:

async function verifyToken(token: string) {
  return firebaseAdmin.auth().verifyIdToken(token, process.env.FIREBASE_AUTH_EMULATOR_HOST != null);
}

With this method I get an error like audience must be myProject-id, it is https://identitytoolkit.googleapis.com/google.identity.identitytoolkit.v1.IdentityToolkit.

When I attempt to add an aud as a custom claim, it throws an error because aud is reserved and cannot be a developer claim.

[looptheloop88]

@vamsiampolu, you may want to create a new issue and indicate the information you've shared here.