Related to this documentation in Angular website:

https://angular.dev/guide/components/inheritance

Simplifying inheritance by removing the need for:

• having a constructor in the parent just for common dependency injection
• having a constructor in the child just for common dependency injection
• calling super for common dependency injection
• calling super for common lifecycle hooks

Stackblitz link:

https://stackblitz.com/edit/stackblitz-starters-tzhggu9s?file=src%2Fmain.ts

Parent component:

@Component({template:``})abstractclassParent{protectedheroService=inject(HeroService);ngOnInit(){this.onInit();}protectedabstractonInit():void;}

Child component:

@Component({selector:'child',template:`Child`,})classChildextendsParent{overrideonInit(){this.heroService.log();}}

App:

@Component({selector:'app-root',template:`<child/>`,imports:[Child],})classApp{}bootstrapApplication(App);

Common service:

@Injectable({providedIn:'root'})classHeroService{log(){console.log('heroService');}}

Advice is to have:

{"compilerOptions":{"noImplicitOverride":true,}}

in tsconfig if not already there.
Goal is to avoid dev to mistakenly write an ngOnInit without knowing they'd be overriding the parent one.