Angular Service singleton constructor called multiple times
As you have declared the TestService as -
@Injectable({ providedIn: 'root'})Which means you are adding to AppRoot module.
No need to add explicitly in the CoreModule, so remove from providers of CoreModule. Remove following -
providers: [ TestService ]As you are adding the TestSevice in CoreModule which is already added in RootModule that's the reason it constructor getting called multiple times.
So use either of one from above.
@Injectable({ providedIn: 'root'})
- The
providedInwithrootoption means, the service is available throughout the application assingletonservice. - It doesn't complain any error like
No provider for xxxservicebcz ofprovidedInif you didn't added to providers list of any module. - If you do adding to the list will leads to creating a new instance of service, which will give you wrong results than expected.
NOTE : Please make sure to use the concept for better results.