How to unit-test canActivate guard method of angular2 using Jasmine?

Question

Sorry for asking this type of question. But I\'m not able to find any blog or youtube tutorials on writing the canActivate guard file testing. Nor in the official documentat

Answer 1

This question is pretty old - but as I was trying to find some detailed unit testing documentation myself right now, I just wanted to put my approach here. In general, if there are dependencies in my guard / service / component / whatever I think these should all be mocked and not the real services should be used. As theses services are not what we want to test in our unit test for the guard - we just want to test the guard. So here is a generic example how I would do it for a guard returning an observable:

import { MyGuard } from './path/to/your/guard';
import { TestBed } from '@angular/core/testing';
import { finalize } from 'rxjs/operators';

describe('MyGuard Test', () => {
    const createMockRoute = (id: string) => {
    return {
      params: { id: id }
    } as any;
  };

  const createMockRouteState = () => null;
  let guard: MyGuard;

  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [
        MyGuard,
      ]
    });

    guard = TestBed.get(MyGuard);
  });

  it('should not be able to activate invalid route', done => {
    const route = createMockRoute(null);
    const state = createMockRouteState();
    const res$ = guard.canActivate(route, state);
    res$.pipe(finalize(done)).subscribe(res => expect(res).toBeFalsy());
  });
});

and this is what I would do in your specific case (should work with angular 6, canActivate should also take 2 params):

import { LoggedInGuard } from './loggedin.guard';
import { TestBed } from '@angular/core/testing';
import { Router } from '@angular/router';
import { StorageService } from '../storage.service';

describe('LoggedInGuard', () => {
  let guard: LoggedInGuard;

  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [
        LoggedInGuard,
        { provide: Router, useClass: { navigate: () => null } },
        { provide: StorageService, useClass: { } }
      ]
    });

    guard = TestBed.get(LoggedInGuard);
  });

  it('should not be able to activate when logged out', () => {
    const storageService = TestBed.get(StorageService);
    storageService.isLoggedIn = false;
    const res = guard.canActivate(null, null);
    expect(res).toBeFalsy();
  });

  it('should be able to activate when logged in', () => {
    const storageService = TestBed.get(StorageService);
    storageService.isLoggedIn = true;
    const res = guard.canActivate(null, null);
    expect(res).toBeTruthy();
  });
});