Angular: How can I test component which uses 'getCurrentNavigation'?

Angular9

I want to test component using jasmine/karma. But I cannot find the way to write test on component which has routing parameter ( using getCurrentNavigation ).

actual component is as below

import { Router } from '@angular/router';

export class myComponent implements OnInit {
  // parameters from previous page
  param1: param1model;
  param2: param2model;
  param3: param3model;

  constructor(
    private router: Router,
     ....
  ) {
    if (this.router.getCurrentNavigation().extras.state.data != undefined) {
      this.param1 = this.router.getCurrentNavigation().extras.state.data.aaa;
      this.param2 = this.router.getCurrentNavigation().extras.state.data.bbb;
      this.param3 = this.router.getCurrentNavigation().extras.state.data.ccc;
    }
  }

and current test code is

import { async, ComponentFixture, TestBed } from '@angular/core/testing';
import { HttpClientModule } from '@angular/common/http';
import { Router, ActivatedRoute } from '@angular/router';
import { myComponent } from './myComponent';
import { RouterTestingModule } from '@angular/router/testing';

describe('myComponent', () => {
  let component: myComponent;
  let fixture: ComponentFixture<myComponent>;
  let router: jasmine.SpyObj<Router>;

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [HttpClientModule, RouterTestingModule],
      declarations: [myComponent],

    }).compileComponents();
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(myComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });
  afterEach(() => {
    TestBed.resetTestingModule();
  });

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

If I run test, I got

TypeError: Cannot read property 'extras' of null And I know it should shows up because this myComponent must receive params (param1,param2,param3). But I don't know how I can receive these params. On Angular official document, I couldn't find any guides for such case.

I appreciate it if someone would share knowledge to me