TypeError: Object(...) is not a function

Question

working on ionic3, angularfire2 v5

TypeError: Object(...) is not a function
    at SwitchMapSubscriber.project (http://localhost:8100/build/vendor.js:73935:76)
    at SwitchMapSubscriber._next (http://localhost:8100/build/vendor.js:61778:27)
    at SwitchMapSubscriber.Subscriber.next (http://localhost:8100/build/vendor.js:20750:18)
    at RefCountSubscriber.Subscriber._next (http://localhost:8100/build/vendor.js:20786:26)
    at RefCountSubscriber.Subscriber.next (http://localhost:8100/build/vendor.js:20750:18)
    at Subject.next (http://localhost:8100/build/vendor.js:23237:25)
    at ConnectableSubscriber.Subscriber._next (http://localhost:8100/build/vendor.js:20786:26)
    at ConnectableSubscriber.Subscriber.next (http://localhost:8100/build/vendor.js:20750:18)
    at Notification.observe (http://localhost:8100/build/vendor.js:51866:50)
    at AsyncAction.DelaySubscriber.dispatch (http://localhost:8100/build/vendor.js:76246:40)

home.ts

import { Component } from '@angular/core';
import {IonicPage, NavController} from 'ionic-angular';
import { Observable } from "rxjs/Observable";
import { Item } from "../../models/item/item.model";
import {ShoppingListServices} from "../../services/shopping-list/shopping-list.services";



@IonicPage()

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {
  shoppingList$: Observable<Item[]>;
  constructor(public navCtrl: NavController,  private shopping: ShoppingListServices) {
    this.shoppingList$=this.shopping
      .getShoppingList()
      .snapshotChanges()
      .map(
        changes => {
          return changes.map(c => ({
            key: c.payload.key, ...c.payload.val()
          }));
        }
      );
  }

}

home.html

<ion-header>
  <ion-navbar color="primary">
    <ion-title>
      Shoping List
    </ion-title>
    <ion-buttons end>
      <button navPush="AddShoppingItemPage" ion-button>
        <ion-icon name="add"></ion-icon>
      </button>
    </ion-buttons>
  </ion-navbar>
</ion-header>

<ion-content padding>
  <ion-list>
    <ion-list-header>
      Items
    </ion-list-header>
    <ion-item *ngFor="let item of shoppingList$ | async">
      {{ item.name }}
    </ion-item>
  </ion-list>
</ion-content>

Answer 1

This works for me, using "angularfire2": "^5.0.0-rc.11"

npm i rxjs@6 rxjs-compat@6 promise-polyfill --save

To retrieve the data:

this.db.list('/customers').valueChanges().subscribe((datas) => { 
  console.log("datas", datas)
},(err)=>{
   console.log("probleme : ", err)
});

Or you can check the GitHub repository for angularfire2 here for more details