Let user specify the firebase app name

src/configTypes.ts

@@ -1,5 +1,5 @@
 import Cookies from 'cookies'
 import { PageURL } from './redirectTypes'
 import { User } from './createUser'
 import { Spread } from './Spread'
 
@@ -90,6 +90,7 @@
     // "G-MEASUREMENT_ID"
     measurementId?: string
   }
+  firebaseClientAppName?: string
   tenantId?: string
   cookies: Omit<Cookies.Option & Cookies.SetOption, 'sameSite'> & {
     // The base name for the auth cookies.

src/createUser.ts

@@ -3,6 +3,7 @@
 import { DecodedIdToken } from 'firebase-admin/auth'
 import isClientSide from 'src/isClientSide'
 import { Claims, filterStandardClaims } from 'src/claims'
+import { getConfig } from './config'
 
 interface UserDeserialized {
   id?: string
@@ -119,8 +120,9 @@
       const { getApp } = require('firebase/app')
       // eslint-disable-next-line global-require,  @typescript-eslint/no-var-requires
       const { getAuth, signOut } = require('firebase/auth')
+      const { firebaseClientAppName } = getConfig()
 
-      signOutFunc = async () => signOut(getAuth(getApp()))
+      signOutFunc = async () => signOut(getAuth(getApp(firebaseClientAppName)))
     }
 
     /**

src/initFirebaseClientSDK.ts

@@ -4,16 +4,20 @@ import { getConfig } from 'src/config'
 import logDebug from 'src/logDebug'
 
 export default function initFirebaseClientSDK() {
-  const { firebaseClientInitConfig, firebaseAuthEmulatorHost, tenantId } =
-    getConfig()
+  const {
+    firebaseClientInitConfig,
+    firebaseAuthEmulatorHost,
+    tenantId,
+    firebaseClientAppName,
+  } = getConfig()
   if (!getApps().length) {
     if (!firebaseClientInitConfig) {
       throw new Error(
         'If not initializing the Firebase JS SDK elsewhere, you must provide "firebaseClientInitConfig" to next-firebase-auth.'
       )
     }
 
-    initializeApp(firebaseClientInitConfig)
+    initializeApp(firebaseClientInitConfig, firebaseClientAppName)
     if (tenantId) {
       getAuth().tenantId = tenantId
     }
@@ -25,6 +29,9 @@ export default function initFirebaseClientSDK() {
   }
   // If the user has provided the firebaseAuthEmulatorHost address, set the emulator
   if (firebaseAuthEmulatorHost) {
-    connectAuthEmulator(getAuth(getApp()), `http://${firebaseAuthEmulatorHost}`)
+    connectAuthEmulator(
+      getAuth(getApp(firebaseClientAppName)),
+      `http://${firebaseAuthEmulatorHost}`
+    )
   }
 }

src/useFirebaseUser.ts

@@ -175,10 +175,19 @@ const useFirebaseUser = () => {
     }
 
     // https://firebase.google.com/docs/reference/js/firebase.auth.Auth#onidtokenchanged
-    const unsubscribe = onIdTokenChanged(getAuth(getApp()), onIdTokenChange)
-    return () => {
-      unsubscribe()
-      isCancelled = true
+    try {
+      const { firebaseClientAppName } = getConfig()
+      logDebug(`[withUser] firebaseClientAppName |${firebaseClientAppName}|`)
+      const app = getApp(firebaseClientAppName)
+      logDebug('[withUser] App loaded', app)
+      const unsubscribe = onIdTokenChanged(getAuth(app), onIdTokenChange)
+      return () => {
+        unsubscribe()
+        isCancelled = true
+      }
+    } catch (error) {
+      logDebug('[withUser] init error', error)
+      throw error
     }
   }, [])