Mastering TypeScript 3 - Third Edition

Angular model tests

To start off with, we will create a series of tests that will check the internal state of the AppComponent class once instantiated, in a file named src/app/app.component.spec.ts as follows:

describe('/src/app/app.component.spec.ts : AppComponent ', () => { 
    let fixture: ComponentFixture<AppComponent>; 
    let app: AppComponent; 
    beforeEach(async(() => { 
        TestBed.configureTestingModule({ 
            declarations: [ 
                AppComponent 
            ], 
            imports: [ 
                FormsModule, 
                ReactiveFormsModule 
            ] 
        }).compileComponents(); 
        fixture = TestBed.createComponent(AppComponent); 
        app = fixture.debugElement.componentInstance; 
 
    })); 
 
}); 

Here, we have defined our test suite with a beforeEach function. We start our test suite by defining two variables named fixture and app