{ provide: MyClass, useClass: MyMockClass }. In this post, we have seen how to create an Azure AD enabled ASP.NET Core Web API application and Angular 8 application and communicate with each other. The new dependency injection system in Angular comes with a feature called Multi Providers that basically enable us, the consumer of the platform, to hook into certain operations and plug in custom functionality we might need in our application use case. Use cases: 1) Don't expose full functionallity How to add providers, service and interceptor only for gift card module in angular? Angular 2 does not have a bootstrap directive (ng-app). The useFactory is used because initializeApp1 is a function and not a class. Check if a user is authenticated. In my case I use it when I need to implement different logic other than a default class provided by the angular. For example ErrorHandler is a defa Angular is a development platform for building mobile and desktop web applications. providers: [ {provide: AuthenticationService, useValue: authServiceMock }, {provide: Router, useValue: routerStub } ] 1. useFactory tells Angular which factory function to use. Aliased class providers. is a form control for selecting a value from a set of options, similar to the native and