Angular Firebase Auth Service

auth.service.ts

import { Injectable } from '@angular/core';
import {
  Auth, authState, createUserWithEmailAndPassword, GoogleAuthProvider, OAuthCredential,
  signInWithCredential, signInWithEmailAndPassword, signInWithPopup, signOut
} from '@angular/fire/auth';
import { FirebaseAuthentication } from '@capacitor-firebase/authentication';
import { Capacitor } from '@capacitor/core';
import { AlertController, LoadingController } from '@ionic/angular';
import { switchMap } from 'rxjs/operators';

import { UserService } from './user.service';

@Injectable({
  providedIn: 'root'
})
export class AuthService {

  constructor(
    private auth: Auth,
    private alertCtrl: AlertController,
    private userService: UserService,
    private loadingCtrl: LoadingController
  ) {
    authState(this.auth)
      .pipe(switchMap(user => this.userService.getUserData(user)))
      .subscribe({
        next: user => {
          if (user) {
            this.userService.currentUser.next(user);
          } else {
            this.userService.currentUser.next(null);
          }
          console.log('currentUser', this.userService.currentUser.value);
        }
      });
  }

  registerUserWithEmailAndPassword(email: string, password: string) {
    createUserWithEmailAndPassword(this.auth, email, password)
      .then(userCredential => this.userService.getUserData(userCredential.user))
      .catch(err => this.showErrorAlert(err));
  }

  signInUserWithEmailAndPassword(email: string, password: string) {
    signInWithEmailAndPassword(this.auth, email, password)
      .then(userCredential => this.userService.getUserData(userCredential.user))
      .catch(err => this.showErrorAlert(err));
  }

  async signInWithGoogle() {
    const isNativePlatform = Capacitor.isNativePlatform();
    const loading = await this.loadingCtrl.create();
    loading.present();
    if (isNativePlatform) {
      const result = await FirebaseAuthentication.signInWithGoogle();
      const oAuthCreds: OAuthCredential = GoogleAuthProvider.credential(result.credential?.idToken);
      signInWithCredential(this.auth, oAuthCreds)
        .then(userCredential => this.userService.getUserData(userCredential.user))
        .then(() => loading.dismiss())
        .catch(err => this.showErrorAlert(err));
    } else {
      signInWithPopup(this.auth, new GoogleAuthProvider())
        .then(userCredential => this.userService.getUserData(userCredential.user))
        .then(() => loading.dismiss())
        .catch(err => this.showErrorAlert(err));
    }
  };

  async signOut() {
    await FirebaseAuthentication.signOut();
    await signOut(this.auth);
  }

  private showErrorAlert(error: any) {
    console.log(error);
    this.alertCtrl.create({
      header: error.error.message,
      message: error.error.error,
      buttons: ['OK']
    }).then(alert => alert.present());
  }
}