create one place where all your mocks are created

firebae_mocks.ts

import JestMockers from "@tests/jest_mockers"
import { Database } from "firebase/database"


namespace FirebaseMocks {
  export function createAppInitMock() {
    const app_mock = jest.fn()
    const initializeAppMock = jest.fn()
    initializeAppMock.mockReturnValue(app_mock)

    JestMockers.mockDefaultExport(
      'firebase/app',
      {
        initializeApp: initializeAppMock,
      }
    )

    return {
      app_mock,
      initializeAppMock,
    }
  }


  export function createMockDb() : {
    actual: Database,
    mock: { app: jest.Mock, type: jest.Mock },
    } {
    const mock = { app: jest.fn(), type: jest.fn() }
    const actual = mock
    // @ts-ignore mock of app is not complete
    return { actual, mock }
  }


  export function mockAnalytics() {
    const getAnalyticsMock = jest.fn()
    const logEventMock = jest.fn()

    JestMockers.mockDefaultExport(
      'firebase/analytics',
      {
        getAnalytics: getAnalyticsMock,
        logEvent: logEventMock,
      }
    )

    return {
      getAnalyticsMock,
      logEventMock,
    }
  }


  export function mockClientDatabase() {
    const getDatabaseMock = jest.fn()
    const goOfflineMock = jest.fn()

    JestMockers.mockDefaultExport(
      'firebase/database',
      {
        getDatabase: getDatabaseMock,
        goOffline: goOfflineMock,
      }
    )

    return {
      getDatabaseMock,
      goOfflineMock,
    }
  }
}


export default FirebaseMocks