angular4 activatedRoute test issue

import { Component, Injectable, Directive, Input, OnInit } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { ActivatedRoute, Router } from '@angular/router';
import { RouterTestingModule } from '@angular/router/testing';
import {
  async,
  TestBed,
  ComponentFixture
 } from '@angular/core/testing';
import { SharedModule } from './shared/shared.module';
import { MaterialModule } from '@angular/material';

import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/of';

@Injectable()
class MockService {
  getThing(id: any) {
    console.log('called with id:', id);
    return Observable.of({ hi: 'there' });
  }
}

@Component({
  selector: 'test-component',
  template: '<div> this is a test </div>'
})
class TestComponent implements OnInit {
  constructor(private activatedRoute: ActivatedRoute, private service: MockService) {}
  ngOnInit() {
    this.activatedRoute.params.subscribe((params: any) => {
      console.log('Hey there, param', params);
      this.service.getThing(params.id);
    });
  }
}

let mockAR: any = {
  params: {
    subscribe: function() {
      console.log('Subscribed.');
      Observable.of({ id: 123 });
    }
  }
}

export function main() {
  xdescribe('My Test Component', () => {
    let fixture: ComponentFixture<TestComponent>;
    let instance: TestComponent;
    let domEl: Element;
    let routeSpy;
    const routes = [
      { path: 'test/:id', component: TestComponent }
    ];
    beforeEach(async(() => {
      routeSpy = spyOn(mockAR.params, 'subscribe').and.callThrough();
      TestBed.configureTestingModule({
        imports: [FormsModule, SharedModule, MaterialModule, RouterTestingModule.withRoutes(routes)],
        declarations: [TestComponent],
        providers: [
          MockService,
          {
            provide: ActivatedRoute, useValue: mockAR,
          }
        ]
      });

      TestBed
        .compileComponents()
        .then(() => {
          fixture = TestBed.createComponent(TestComponent);
          instance = fixture.debugElement.componentInstance;
          domEl = fixture.debugElement.nativeElement;
        });
    }));

    it('should work',
      async(() => {
        let mockService =
          fixture.debugElement.injector.get<any>(MockService) as MockService;
        // let serviceSpy = spyOn(mockService, 'getThing').and.callThrough();

        fixture.detectChanges();
        expect(routeSpy.calls.count()).toBe(1);
        // expect(serviceSpy.calls.count()).toBe(1);
      }));
  });
}

Can you help me?