Authentication error when using database with emulators #2034

import admin from 'firebase-admin'

process.env.GCLOUD_PROJECT = 'demo'
process.env.FIREBASE_AUTH_EMULATOR_HOST = 'localhost:9099'

const demoApp = admin.initializeApp({
    databaseURL: 'http://localhost:9000/?ns=demo-default-rtdb',
})

// This uses the emulator and works.
await demoApp.auth().listUsers()
    .then(l => console.log(l))

// This fails with FirebaseAppError.
// code: app/invalid-credential
// Credential implementation provided to initializeApp() via the "credential" property failed to fetch a valid Google OAuth2 access token with the following error: "Error fetching access token: Error while making request: getaddrinfo ENOTFOUND metadata.google.internal. Error code: ENOTFOUND"
// in firebase-admin/lib/app/firebase-app.js:85:19
await demoApp.database().getRules()
    .then(r => console.log(r))

import admin from 'firebase-admin'

process.env.GCLOUD_PROJECT = 'demo'
process.env.FIREBASE_AUTH_EMULATOR_HOST = 'localhost:9099'

const demoApp = admin.initializeApp({
    credential: {
        getAccessToken: () => Promise.resolve({access_token: 'foo', expires_in: 3600}),
    },
    databaseURL: 'http://localhost:9000/?ns=demo-default-rtdb',
})

await demoApp.auth().listUsers()
    .then(l => console.log(l))

await demoApp.database().getRules()
    .then(r => console.log(r))