Firebase features injection tokens

firebase-tokens.ts

const app = initializeApp(environment.firebase);

export const AUTH = new InjectionToken('Firebase auth', {
  providedIn: 'root',
  factory: () => {
    const auth = getAuth();
    if (environment.useEmulators) {
      connectAuthEmulator(auth, 'http://localhost:9099', {
        disableWarnings: true,
      });
    }
    return auth;
  },
});

export const FIRESTORE = new InjectionToken('Firebase firestore', {
  providedIn: 'root',
  factory: () => {
    const firestore = getFirestore(app);
    if (environment.useEmulators) {
      connectFirestoreEmulator(firestore, 'localhost', 8080);
    }
    return firestore;
  },
});

export const STORAGE = new InjectionToken('Firebase storage', {
  providedIn: 'root',
  factory: () => {
    const storage = getStorage();
    if (environment.useEmulators) {
      connectStorageEmulator(storage, 'localhost', 9199);
    }
    return storage;
  },
});

export const FUNCTIONS = new InjectionToken('Firebase functions', {
  providedIn: 'root',
  factory: () => {
    const functions = getFunctions(getApp());
    if (environment.useEmulators) {
      connectFunctionsEmulator(functions, 'localhost', 5001);
    }
    return functions;
  },
});

These tokens are defined to be used with rxfire;