"TypeError: Cannot read property 'pipe' of undefined" - Do I miss additional setup in my unit tests ( Angular / Unit testing / ActivatedRoute )

Question

I'm currently facing an issue where I have an Observable based on the paramMap of my activatedRoute

this.current$ = this.route.paramMap.pipe(map(paramMap => paramMap.get('title')));

It's working nice on my front-end, but I recently started using angular unit tests, and I have a very basic test to start out. Which currently only holds:


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

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

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

For some reason, when running my test. It is erroring on the following.

TypeError: Cannot read property 'pipe' of undefined

I have some other simple tests setup, but they all fail on this above message. Do I miss something here?

Thanks in advance.

`paramMap` will be null as your test has no routing - you need to mock `ActivatedRoute` - see https://stackoverflow.com/questions/45917883/how-do-you-mock-activatedroute — wlf, Feb 19 '22 at 01:52

score 0 · Accepted Answer · answered Feb 19 '22 at 07:02

You can try to mock the Route like:

 `` 
    {
      provide: ActivatedRoute,
      useValue: {
        snapshot: {
          paramMap: {
            get: (key: string) => {
              switch (key) {
                case 'title':
                  return 'my title';
                case 'subtitle':
                  return 'my subtitle'
              }
            }
          },
        },
      },
    }``

"TypeError: Cannot read property 'pipe' of undefined" - Do I miss additional setup in my unit tests ( Angular / Unit testing / ActivatedRoute )

1 Answers1