import { async, ComponentFixture, TestBed } from '@angular/core/testing'; import { CounterComponent } from './counter.component'; describe('CounterComponent', () => { let component: CounterComponent; let fixture: ComponentFixture; beforeEach(async(() => { TestBed.configureTestingModule({ declarations: [ CounterComponent ] }) .compileComponents(); })); beforeEach(() => { fixture = TestBed.createComponent(CounterComponent); component = fixture.componentInstance; fixture.detectChanges(); }); it('should display a title', async(() => { const titleText = fixture.nativeElement.querySelector('h1').textContent; expect(titleText).toEqual('Counter'); })); it('should start with count 0, then increments by 1 when clicked', async(() => { const countElement = fixture.nativeElement.querySelector('strong'); expect(countElement.textContent).toEqual('0'); const incrementButton = fixture.nativeElement.querySelector('button'); incrementButton.click(); fixture.detectChanges(); expect(countElement.textContent).toEqual('1'); })); });