firebase-my-app.tsx

import '@ionic/core';
import '@stencil/core';
import { Component, Prop, Listen } from '@stencil/core';
import { ToastController } from '@ionic/core';
import { firebaseConfig } from '../../helpers/config';
import firebase from 'firebase';

@Component({
  tag: 'my-app',
  styleUrl: 'my-app.scss'
})
export class MyApp {

  @Prop({ connect: 'ion-toast-controller' }) toastCtrl: ToastController;

  configureFirebase() {
    firebase.initializeApp(firebaseConfig);
    console.log('Firebase Configured!', firebase);
  }

  componentWillLoad() {
    this.configureFirebase();
  }