Myujth

My purpose is simply to test one function. I cannot figure out how to mock firebase properly. I try to keep the example with axios mocking from Jest docs. I have the following code:

MusicService.js

import initializeApp from "firebase/app";
import "firebase/database";

const firebase = initializeApp(
 apiKey: "<API_KEY>",
 authDomain: "<PROJECT_ID>.firebaseapp.com",
 databaseURL: "https://<DATABASE_NAME>.firebaseio.com",
 projectId: "<PROJECT_ID>",
 storageBucket: "<BUCKET>.appspot.com",
 messagingSenderId: "<SENDER_ID>",
);

export class MusicService 
 static getAlbums() 
 return firebase.database().ref("albums").once("value")
 .then(snapshot => Object.values(snapshot.val()));
 

MusicService.test.js

import firebase from 'firebase/app';
import 'firebase/database';
import MusicService from './MusicService';

jest.mock('firebase/app');
jest.mock('firebase/database');

test("test", () => 
 firebase.initializeApp.mockImplementation(() => 
 database: jest.fn(() => 
 return 
 ref: jest.fn()
 
 )
 );

 MusicService.getAlbums();
);

The problem is that I get the following error:

I tried to mock firebase.database.

test("test", () => 
 firebase.mockImplementation(() => 
 return 
 database: 

 
 
 );
 MusicService.getAlbums();
);

But in this case I get the error that says:

TypeError: _app.default.mockImplementation is not a function.

I don't expect the working example will be given, but rather could you tell please, what exactly should I mock? The whole firebase library or maybe the part where my function starts - return firebase.database().