Nested function test coverage in Angular with Jasmine

I have an issue trying to test the removal of a cookie using a directive.

My directive is the following one:

import { Directive, HostListener } from '@angular/core';
import { CookieService } from 'angular2-cookie/core';

@Directive({
  selector: '[appCloseWindow]'
})

/**
 * Directive that when we close the window, removes the cookie
 */
export class CloseWindowDirective {

  constructor( private readonly _cookieService: CookieService ) { }

  @HostListener('window:beforeunload', ['$event'])
  beforeunloadHandler(event: Event) {
    const cookie = this._cookieService.get('RandomCookie');
    if ( cookie !== undefined ) {
      this._cookieService.remove('RandomCookie');
    }
  }
}

So in the test my problem is that I am not able to reach the remove part, and dont know how to do it.

My test right now is this, I am new doing Tests with Jasmine so probably are wrong...

import { TestBed, async } from '@angular/core/testing';
import { CloseWindowDirective } from './close-window.directive';
import { CookieService } from 'angular2-cookie';

fdescribe('Directive: CloseWindow', () => {
  const service = new CookieService;
  const directive = new CloseWindowDirective(new CookieService);

  beforeEach(async(() => {
    spyOn(directive, 'beforeunloadHandler').and.callThrough();
    spyOn(service, 'get').and.returnValue('cookieTest');
    spyOn(service, 'remove').and.callThrough();

    TestBed.configureTestingModule({
      providers: [CookieService],
      declarations: [CloseWindowDirective]
    })
      .compileComponents();
  }));

  it('should create an instance', () => {
    expect(directive).toBeTruthy();
  });

  it('should call directive method', () => {
    directive.beforeunloadHandler(new Event('beforeunload'));
    expect(directive.beforeunloadHandler).toHaveBeenCalled();
  });

  it('should call remove the cookie', () => {
    const cookie = service.get('testCookie');
    service.remove(cookie);
    expect(service.remove).toHaveBeenCalled();
  });
});

Thanks in advance.