ngOnDestroy上的jasmine测试失败

import { Component, OnDestroy } from '@angular/core';
import { Subscription } from 'rxjs';

@Component({
  selector: 'app-example',
  template: `<div>Example Component</div>`
})
export class ExampleComponent implements OnDestroy {
  private subscription: Subscription;

  constructor() {
    this.subscription = new Subscription();
  }

  ngOnDestroy() {
    this.subscription.unsubscribe();
  }
}

import { ComponentFixture, TestBed } from '@angular/core/testing';
import { ExampleComponent } from './example.component';

describe('ExampleComponent', () => {
  let component: ExampleComponent;
  let fixture: ComponentFixture<ExampleComponent>;

  beforeEach(async () => {
    await TestBed.configureTestingModule({
      declarations: [ ExampleComponent ]
    })
    .compileComponents();
  });

  beforeEach(() => {
    fixture = TestBed.createComponent(ExampleComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it('should create', () => {
    expect(component).toBeTruthy();
  });

  it('should unsubscribe on ngOnDestroy', () => {
    spyOn(component.subscription, 'unsubscribe').and.callThrough();
    component.ngOnDestroy();
    expect(component.subscription.unsubscribe).toHaveBeenCalled();
  });
});

import { Component, OnDestroy } from '@angular/core';
import { Subject } from 'rxjs';
import { takeUntil } from 'rxjs/operators';

@Component({
  selector: 'app-example',
  template: `<div>Example Component</div>`
})
export class ExampleComponent implements OnDestroy {
  private destroy$ = new Subject<void>();

  constructor() {
    someObservable$.pipe(takeUntil(this.destroy$)).subscribe();
  }

  ngOnDestroy() {
    this.destroy$.next();
    this.destroy$.complete();
  }
}

beforeEach(async () => {
  await TestBed.configureTestingModule({
    declarations: [ ExampleComponent ]
  })
  .compileComponents();
});

beforeEach(() => {
  fixture = TestBed.createComponent(ExampleComponent);
  component = fixture.componentInstance;
  fixture.detectChanges();
});