How to mock router in angular jasmine spec

Question

I am new to writing test specs using jasmine. I have a condition in ngOnInit() something like, router.url.includes(some string). The default spec test case which checks component to be truthy is getting failed saying TypeError: Cannot find includes of undefined. Is there any way to spy or mock includes?

Answer 1

You can use RouterTestingModule to mock the angular router.

Just import the angular router as below.

import { RouterTestingModule } from '@angular/router/testing';
import { ActivatedRoute, Router } from '@angular/router';

And add it to the imports array of NgModule

TestBed.configureTestingModule({
    declarations: [
        someComponent
    ],
    imports: [
        RouterTestingModule.withRoutes([]),
    ],
    providers: [someProvider],
}).compileComponents

Then you can inject the Router as follows and use it for testing

it('should Navigate', () => {
    const actiavtedRoute = TestBed.inject(ActivatedRoute);
    const router = TestBed.inject(Router);
})