Angular 6 - can't resolve all parameters for AppComponent

Question

I am trying to build an application with Angular 6 and I am still setting everything up. But it seems there is something wrong with the dependency injection in my app.

Answer 1

I also experienced the same issue with Angular 8.2.13 + Typescript. Finally the trick was to use a @Inject('RefOnlyUsedForTesting'), even if the type is string.

export abstract class MyBaseClass {
  ....
  constructor(@Inject(ElementRef) elementRef: ElementRef,
          @Optional() @Inject('RefOnlyUsedForTesting') dep1: MyObject,
          @Optional() @Inject('RefOnlyUsedForTesting') dep2: string,
          @Optional() @Inject('RefOnlyUsedForTesting') dep3: string) {
  super();    
  ...
 }
}