Angular service testing (constructor)

service.spec.ts

import { inject, TestBed } from '@angular/core/testing';
import { of } from 'rxjs/observable/of';
import { LoggingService, LocalStorageService } from '../';
import { RouterEventService } from '../../routing';

export class MockLocalStorageService {
    setItem() {}
    getItem() { return []; }
}
export class MockRouterEventService {
    endEvents() {
        return of({url: 'test/redirect', urlAfterRedirects: 'test/test'})
    }
}

describe('The LoggingService', () => {
    let mockStorage = new MockLocalStorageService();
    let mockRouterEventService = new MockRouterEventService();

    beforeEach(() => {
        spyOn(mockStorage, 'getItem');
        spyOn(mockStorage, 'setItem');
        spyOn(mockRouterEventService, 'endEvents').and.callThrough();
    });

    beforeEach(() => TestBed.configureTestingModule({
        providers: [        
            { provide: LocalStorageService,  useValue: mockStorage },
            { provide: RouterEventService,  useValue: mockRouterEventService },
            LoggingService
        ]
    }));

    it('should exist', inject([LoggingService], (loggingService : LoggingService) => {
        expect(loggingService).toBeDefined();
    }));

    it('should retrieve previous history from localStorage', inject([LoggingService], (loggingService : LoggingService) => {
        expect(mockStorage.getItem).toHaveBeenCalledTimes(1);
        expect(mockStorage.getItem).toHaveBeenCalledWith('history');
    }));
    
    // etc

});