Can't bind to 'routerLink' since it isn't a known property of 'a'. ("<header id="header">

Solution 1:

When you use the TestBed you are configuring a module from scratch. In your current configuration, all you have is

TestBed.configureTestingModule({
  declarations: [
    AppComponent
  ],
});

So all that's included in the module for the test environment is the AppComponent. Nothing from the AppModule is included.

So you're getting the error because you are missing all the router directives that are included in the RouterModule. You could import the RouterModule, but for tests, you should instead use the RouterTestingModule

import { RouterTestingModule } from '@angular/core/testing'

TestBed.configureTestingModule({
  imports: [
    RouterTestingModule.withRoutes([])
  ],
  declarations: [
    AppComponent
  ],
});

You can add routes to the withRoutes.

See Also:

• Angular 2 unit testing components with routerLink

Solution 2:

This is your app.component.spec.ts

You should also add routerModule there

beforeEach(() => {
    TestBed.configureTestingModule({
      declarations: [
        AppComponent
      ],
      imports:[RouterModule.forRoot([])] //add the router module here as well
    });
    TestBed.compileComponents();
  });

When you're testing your AppComponent , like I said , you should give the test bed what ever you've given to your root @NgModule , so :

 beforeEach( () => {
    TestBed.configureTestingModule( {
        imports : [
            BrowserModule,
            FormsModule,
            HttpModule,
            RouterTestingModule.withRoutes( [
                { path : '', redirectTo : '/home', pathMatch : 'full' },
                { path : 'home', component : HomeComponent },
                { path : 'about', component : AboutComponent },
                { path : 'experiments', component : ExperimentsComponent },
                { path : '**', component : HomeComponent }
            ] )
        ],
        declarations : [
            AppComponent,
            AboutComponent,
            HomeComponent,
            ExperimentsComponent,
            ExperimentDetailComponent
        ],

        schemas : [
            CUSTOM_ELEMENTS_SCHEMA
        ],
        providers : [
            ExperimentsService,
            StateService
        ]
    } );
    TestBed.compileComponents();
} );