Ошибка: StaticInjectorError (DynamicTestModule) [AuthService -> Http]:

Question

Во время тестов появляется сообщение об ошибке:

Error: StaticInjectorError(DynamicTestModule)[AuthService -> Http]: 
  StaticInjectorError(Platform: core)[AuthService -> Http]: 
    NullInjectorError: No provider for Http!
    at _NullInjector.webpackJsonp../node_modules/@angular/core/esm5/core.js._NullInjector.get (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:1003:1)
    at resolveToken (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:1301:1)
    at tryResolveToken (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:1243:1)
    at StaticInjector.webpackJsonp../node_modules/@angular/core/esm5/core.js.StaticInjector.get (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:1111:1)
    at resolveToken (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:1301:1)
    at tryResolveToken (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:1243:1)
    at StaticInjector.webpackJsonp../node_modules/@angular/core/esm5/core.js.StaticInjector.get (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:1111:1)
    at resolveNgModuleDep (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:10896:1)
    at _createClass (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:10935:1)
    at _createProviderInstance$1 (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/esm5/core.js:10907:1)

мой скрипт auth.service.spec.ts :

describe('AuthService', () => {
  let injector: TestBed;
  let service: AuthService;
  let httpMock: HttpTestingController;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [HttpClientTestingModule, RouterTestingModule] ,
      providers: [AuthService]
    });
    injector = getTestBed();
    service = injector.get(AuthService);
    httpMock = injector.get(HttpTestingController);
  });

  it('should be created', inject([AuthService], (service: AuthService) => {
    expect(service).toBeTruthy();
  }));
});

Добавление класса HttpClientTestingModuleна импорт не помогает.Что я должен сделать, чтобы исправить ошибку в тестах?