App init service for loading feature flags

app-init.service

@Injectable({
  providedIn: 'root'
})
export class AppInitService {
  constructor(private httpClient: HttpClient, private featureToggleService: FeatureToggleService) {}

  public init() {
    return this.httpClient
      .get('assets/feature-config.json')
      .pipe(tap((features) => (this.featureToggleService.features = features as any)))
      .toPromise();
  }
}