Add ability to use inject() for element injector hierarchy

Which @angular/* package(s) are the source of the bug?

core

Is this a regression?

No

Description

When providing a Service in a component, inject() triggers NullInjectorError when called within runInContext :

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css'],
  providers: [Service],
})
export class AppComponent {
  public constructor(injector: EnvironmentInjector, service: Service) {
    console.log(service); // OK
    console.log(inject(Service)); //OK

    setTimeout(() => {
      injector.runInContext(() => {
        console.log(inject(Service)); //KO
      });
    }, 100);
  }
}

This does not happen

• if the service is providedIn:'root'
• if the service is provided in the module

Please provide a link to a minimal reproduction of the bug

https://stackblitz.com/edit/angular-ivy-yccqgi?file=src%2Fapp%2Fapp.component.ts,src%2Fapp%2Fapp.component.html

Please provide the environment you discovered this bug in (run ng version)

Angular 14.2.3

[antischematic]

It’s possible to create an environment injector that inherits from the node injector, would it be possible to widen the type signature so that createEnvironmentInjector allows this without a type cast? Alternatively, could we get runInContext added to the Injector class?

@Component({
  providers: [Service]
})
class AppComponent {
  constructor(parent: Injector) {
    const injector= createEnvironmentInjector([], parent as EnvironmentInjector)
    setTimeout(() => {
      injector.runInContext(() => {
        console.log(inject(Service)); // now it works
      });
    }, 100);
  }
}

[JeanMeche]

Thx @pkozlowski-opensource, It this mentioned somewhere in the documentation ? If not, it would be a good idea to add it.

In my use case, I have objects created outside DI, but they still need to get access to injected services.