How do I Mock RouterStateSnapshot for a Router Gua

Question

I have a simple router guard and I am trying to test the canActivate( route: ActivatedRouteSnapshot, state: RouterStateSnapshot ). I can create the ActivatedRouteSnapshot like this new ActivatedRouteSnapshot() but I cannot figure out how to create a mocked RouterStateSnapshot.

Per the code I tried...

let createEmptyStateSnapshot = function(
    urlTree: UrlTree, rootComponent: Type<any>){
    const emptyParams = {};
    const emptyData = {};
    const emptyQueryParams = {};
    const fragment = '';
    const activated = new ActivatedRouteSnapshot();
    const state = new RouterStateSnapshot(new TreeNode<ActivatedRouteSnapshot>(activated, []));
    return {
        state: state,
        activated: activated
    }
}

But import {TreeNode} from "@angular/router/src/utils/tree"; seems to need to be transpiled or something because I get...

Uncaught SyntaxError: Unexpected token export at webpack:///~/@angular/router/src/utils/tree.js:8:0 <- test.bundle.ts:72431

Answer 1

I needed to get the data in the route to test for user roles in my guard, so I mocked it this way:

class MockActivatedRouteSnapshot {
    private _data: any;
    get data(){
       return this._data;
    }
}

describe('Auth Guard', () => {
   let guard: AuthGuard;
   let route: ActivatedRouteSnapshot;

   beforeEach(() => {
      TestBed.configureTestingModule({
         providers: [AuthGuard, {
            provide: ActivatedRouteSnapshot,
            useClass: MockActivatedRouteSnapshot
        }]
      });
      guard = TestBed.get(AuthGuard);
  });

  it('should return false if the user is not admin', () => {
     const expected = cold('(a|)', {a: false});

     route = TestBed.get(ActivatedRouteSnapshot);
     spyOnProperty(route, 'data', 'get').and.returnValue({roles: ['admin']});

     expect(guard.canActivate(route)).toBeObservable(expected);
  });
});

Answer 2

I managed to do it slightly differently but it should work for you :

...

let mockSnapshot:any = jasmine.createSpyObj<RouterStateSnapshot>("RouterStateSnapshot", ['toString']);

@Component({
  template: '<router-outlet></router-outlet>'
})
class RoutingComponent { }

@Component({
  template: ''
})
class DummyComponent { }

describe('Testing guard', () => {
  beforeEach(() => TestBed.configureTestingModule({
    imports: [
      RouterTestingModule.withRoutes([
        {path: 'route1', component: DummyComponent},
        {path: 'route2', component: DummyComponent},
        ...
      ])
  ],
  declarations: [DummyComponent, RoutingComponent],
  providers: [
    GuardClass,
    {provide: RouterStateSnapshot, useValue: mockSnapshot}
  ]
}).compileComponents());

  it('should not allow user to overcome the guard for whatever reasons', 
    inject([GuardClass], (guard:GuardClass) => {
      let fixture = TestBed.createComponent(RoutingComponent);
      expect(guard.canActivate(new ActivatedRouteSnapshot(), mockSnapshot)).toBe(false);
  })
 ...

Answer 3

Based on a previous question I had about Router I tried this...

let mockSnapshot: any;
...
mockSnapshot = jasmine.createSpyObj("RouterStateSnapshot", ['toString']);
...
TestBed.configureTestingModule({
  imports: [RouterTestingModule],
  providers:[
    {provide: RouterStateSnapshot, useValue: mockSnapshot}
  ]
}).compileComponents();
...
let test = guard.canActivate(
  new ActivatedRouteSnapshot(),
  TestBed.get(RouterStateSnapshot)
);

The problem I now have is that I need the toString here mockSnapshot = jasmine.createSpyObj("RouterStateSnapshot", ['toString']);. This is because jasmine createSpyObj requires at least one mocked method. Since I am not testing the side effects of RouterStateSnapshot, this seems like extra work for nothing.