Component with routerLinkActive fails to compile for testing

I am writing test for sibebar navigation component. Each link contains routerLink and routerLinkActive directives. If I remove routerLinkActive directive from all link, everything is fine, but with routerLinkActive it gives me an error TypeError: Cannot read property 'subscribe' of undefined at new RouterLinkWithHref

Here is an example of my links in html:

<li>
 <a class="tab" [routerLink]="['dashboard']" [routerLinkActive]="active">
  Dashboard
 </a>
</li>

My test file:

describe('SideBarComponent', () => {
  let component: SideBarComponent;
  let fixture: ComponentFixture<SideBarComponent>;

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [
        RouterTestingModule.withRoutes(appRoutes)
      ],
      declarations: [SideBarComponent],
      providers: [
        {
          provide: UserService, useClass: UserServiceMock
        },
        {
          provide: Router, useClass: RouterStub
        },
        {
          provide: ActivatedRoute, useClass: ActivatedRouteStub
        }
       ]
    }).compileComponents();
 }));

 beforeEach(() => {
   fixture = TestBed.createComponent(SideBarComponent);
   component = fixture.componentInstance;
   fixture.detectChanges();
 });