How do I properly test a custom icon function?

I have a function that returns a leaflet icon with some properties:

addSimpleIcon(
    iconUrl,
    iconRetinaUrl: string = null,
    iconHeight: number = 20,
    iconWidth: number = 20
  ): Icon {
    const icon: Icon = L.icon({
      iconUrl,
      iconRetinaUrl,
      iconSize: [iconWidth, iconHeight], 
      shadowSize: [0, 0],
      iconAnchor: [iconWidth / 2, iconHeight / 2], 
      shadowAnchor: [0, 0], 
      popupAnchor: [0, 0]
    });
    return icon;
  }

Here is my test

it('should return a simple icon with properties', () => {
    const test = 'testUrl';
    const anotherTestString = 'test';
    const testHeight = 2;
    const testWidth = 2;
    expect(
      service.addSimpleIcon(test, anotherTestString, testHeight, testWidth)
    ).toEqual(anotherTestIcon);
  });

Here is that const that the test is seeing if it is equal:

const anotherTestIcon: Icon = L.icon({
    iconUrl: 'testUrl',
    iconRetinaUrl: 'test',
    iconSize: [2, 2],
    shadowSize: [0, 0],
    iconAnchor: [20 / 2, 20 / 2],
    shadowAnchor: [0, 0],
    popupAnchor: [0, 0]
  });

My overall thinking is I want to make sure that these values are getting set properly but I’m coming across this error here:

Expected $.options.iconAnchor[0] = 1 to equal 10.
Expected $.options.iconAnchor[1] = 1 to equal 10.

I know it’s expecting the iconAnchor, shadowAnchor, and popupAnchor but how can I pass these in if the method only takes four parameters, right?

Is there a better way to test this function?

>Solution :

I think maybe your setup is off. Looks like "anotherTestIcon" is passed in but is never defined.

Here’s a working example: https://stackblitz.com/edit/github-test-run-draft-fn737v?file=src/app/app.component.spec.ts

Try changing your test to look more like this:

  it('should return a simple icon with properties', () => {
    const anotherTestIcon = {
      iconUrl: 'foop',
      iconRetinaUrl: 'doop',
      iconSize: [1, 1],
      shadowSize: [0, 0],
      iconAnchor: [1 / 2, 1 / 2],
      shadowAnchor: [0, 0],
      popupAnchor: [0, 0],
    };

    const result = component.addSimpleIcon(
      anotherTestIcon.iconUrl,
      anotherTestIcon.iconRetinaUrl,
      1,
      1
    );

    expect(result).toEqual(anotherTestIcon);
  });