How to reduce boiler and repeatitive code when writing test cases - angular6

Question

I am writing a lot of boiler and duplicate code in each describe section of my app-component.spec.ts. Is there a way to reduce it? Another problem is that whenever I write a new component, I have to explicitly add reference of the new component in each describe. For eg.
describe('AppComponent Test suite', () => {
let component: AppComponent;
let fixture: ComponentFixture<AppComponent>;
beforeEach((() => {
TestBed.configureTestingModule({
declarations: [
AppComponent,
... //29 components need to be referrred her
],
imports: [
AppRoutingModule,
QuillModule,
BrowserModule,
HttpClientModule,
MatProgressBarModule,
BrowserAnimationsModule,
HttpClientXsrfModule.withOptions({cookieName: 'CJCsrfCookie', headerName: 'CJCsrfHeader'}),
ReactiveFormsModule
],
providers: [{provide: APP_BASE_HREF, useValue: '/'},
...//14 services need to be added here
}).compileComponents();
}));
beforeEach(() => {
fixture = TestBed.createComponent(AppComponent);
component = fixture.componentInstance;
fixture.detectChanges();
});
fit('should create the app', (async() => {
expect(component).toBeTruthy();
}));
...
});
If I write another describe, I'll have to write all the imports and declarations again. Can I avoid this?

Answer 1

It seems it is quite easy to do it unless I am mistaken!
I just import the AppModule. For any providers I want to provide an alternate of, I just mention that explicitly.
eg.
beforeEach(async(() => {
TestBed.configureTestingModule({
imports: [AppModule],
providers: [
{provide: UserManagementService, useClass: MockUserManagementService}, //mock user management service
],
})
.compileComponents();
}));
The above replaces
beforeEach(async(() => {
TestBed.configureTestingModule({
declarations: [//23 components. These in new implementation come from AppModule
],
imports: [AppModule],
providers: [//14 services. They also some now from AppModule,
{provide: UserManagementService, useClass: MockUserManagementService}, //mock user management service
{provide: APP_BASE_HREF, useValue: '/'}],
})
.compileComponents();
}));