autoUnsubscribe-ivy-hoc.ts

export function autoUnsubscribe(subscriptions: string[] = []) {
    return (componentType) => {
        const orgFactory = componentType.ngComponentDef.factory;

        componentType.ngComponentDef.factory = (...args) => {
            const component = orgFactory(...args);

            componentType.ngComponentDef.onDestroy = () => {
                if (component.ngOnDestroy) {
                    component.ngOnDestroy();
                }

                if (subscriptions && subscriptions.length) {
                    // Unsubscribe for specific subscriptions
                    subscriptions.forEach(key => {
                        if (component[key] && component[key].unsubscribe) {
                            console.log([key, component[key]])
                            component[key].unsubscribe();
                        }
                    })
                } else {
                    // Unsubscribe for all keys
                    Object.keys(component)
                        .forEach(key => {
                            if (component[key] && component[key].unsubscribe) {
                                console.log([key, component[key]])
                                component[key].unsubscribe();
                            }
                        });

                }

            };

            return component;
        };
        return componentType;
    };
}

home.component.ts

import { Component, OnInit } from '@angular/core';
import { Subscription, timer } from 'rxjs';
import { tap } from 'rxjs/operators';
import { autoUnsubscribe } from '../../unsubscribe';

// @autoUnsubscribe(['timerSubscription'])
@autoUnsubscribe()
@Component({
  selector: 'app-home',
  templateUrl: './home.component.html',
  styleUrls: ['./home.component.css']
})
export class homeComponent implements OnInit {
  timerSubscription: Subscription;
  constructor() { }

  ngOnInit() {
    this.timerSubscription = timer(0, 1000)
      .pipe(
        tap(console.log),
      )
      .subscribe(
      )
  }
}