npm install ngx-watcher --save

@NgModule({
  ...
  providers: [NgxWatcherService],
  ...
})
export class AppModule { }

 import {KvWatcher, IterWatcher, NgxWatcherService} from 'ngx-watcher';

 @Component({...})
  export class TestComponent implements DoCheck {
 
   private kvWatcher: KvWatcher<any>;
   private iterWatcher: IterWatcher<any>;
 
   value = {}; // keyValue тип
   array = []; // итерируемый тип
 
   constructor(private service: NgxWatcherService) {
     this.kvWatcher = service.of(this.value);
     this.iterWatcher = service.ofIter(this.array);
   }
 
   ngDoCheck(): void {
     this.kvWatcher.watch(
       this.value,
       v => console.log(`change after value:`, v),
       (t, v) => console.log(`changed value: WatchChangeType=${t} ${v.key} ${v.previousValue} ${v.currentValue}`)
     );
 
     this.iterWatcher.watch(
       this.array,
       v => console.log(`change after value:`, v),
       (t, v) => console.log(`changed value: WatchChangeType=${t} ${v.currentIndex} ${v.item} ${v.previousIndex} ${v.trackById}`)
     );
   }
 }

npm run build:lib