fix: firebase auth issues on ios

src/app/shared/services/auth/providers/firebase.auth.ts

@@ -1,9 +1,11 @@
 import { Injectable, Injector } from "@angular/core";
 import { FirebaseAuthentication, User } from "@capacitor-firebase/authentication";
-import { getAuth } from "firebase/auth";
+import { getAuth, initializeAuth, indexedDBLocalPersistence, Auth } from "firebase/auth";
 import { FirebaseService } from "../../firebase/firebase.service";
 import { AuthProviderBase } from "./base.auth";
 import { IAuthUser } from "../types";
+import { FirebaseApp } from "firebase/app";
+import { Capacitor } from "@capacitor/core";
 
 /** LocalStorage field used to store temporary auth profile data */
 const AUTH_METADATA_FIELD = "firebase_auth_openid_profile";
@@ -14,12 +16,15 @@ export type FirebaseAuthUser = User;
   providedIn: "root",
 })
 export class FirebaseAuthProvider extends AuthProviderBase {
+  private auth: Auth;
+
   public override async initialise(injector: Injector) {
     const firebaseService = injector.get(FirebaseService);
     // TODO - is service required here?
     if (!firebaseService.app) {
       throw new Error("[Firebase Auth] app not configured");
     }
+    this.initialiseAuth(firebaseService.app);
     await this.handleAutomatedLogin();
   }
 
@@ -43,6 +48,22 @@ export class FirebaseAuthProvider extends AuthProviderBase {
     return this.authUser();
   }
 
+  /**
+   * Configure Firebase Auth to use indexedDB for persistence on native platforms.
+   * Default mechanism (cookies?) may not be available from capacitor://localhost domains (e.g. on ios)
+   * See https://stackoverflow.com/a/74904270
+   * and https://firebase.google.com/docs/auth/web/custom-dependencies#platform-specific_considerations
+   */
+  private initialiseAuth(app: FirebaseApp) {
+    if (Capacitor.isNativePlatform()) {
+      this.auth = initializeAuth(app, {
+        persistence: indexedDBLocalPersistence,
+      });
+    } else {
+      this.auth = getAuth();
+    }
+  }
+
   private setAuthUser(user: User, profile: Partial<IAuthUser>) {
     const authUser: IAuthUser = {
       ...profile,
@@ -59,7 +80,7 @@ export class FirebaseAuthProvider extends AuthProviderBase {
   private async handleAutomatedLogin() {
     // use firebase authStateReady to ensure any previously logged in user is available
     // and update the auth user with loaded profile
-    await getAuth().authStateReady();
+    await this.auth.authStateReady();
     const { user } = await FirebaseAuthentication.getCurrentUser();
     if (user) {
       const storedProfile = localStorage.getItem(AUTH_METADATA_FIELD);