firebase.firestore() is not a function when trying to initialize Cloud Firestore

Question

When I try to initialize Firebase Cloud Firestore, I ran into the following error:

Uncaught TypeError: WEBPACK_IMPORTED_MODULE_0_firebase

Answer 1

Solution for Angular 8 (as of 4th January 2020):

1. Delete package-lock.json file
2. Run npm install
3. import AngularFirestoreModule from @angular/fire/firestore

Just need to import AngularFirestoreModule.

// App.module.ts

import { AngularFireModule } from '@angular/fire';
import { AngularFirestore, AngularFirestoreModule } from '@angular/fire/firestore';
import { AngularFireDatabaseModule } from '@angular/fire/database';
imports: [
    AngularFireModule.initializeApp(environment.firebaseConfig),
    AngularFirestoreModule,
    AngularFireDatabaseModule
]