more detailed test

bag.spec.ts

//testing both success and fail status  
it('should handle Add to bag Message', () => {
    const msg: BagResponse = {
      actionType: 'add',
      category: 'bag',
      product: { colorId: '01', productId: '23423', sizeId: 'SM003' },
      status: 'success'
    };
    component.chooseMessageHandler(msg);
    expect(component.bag[0]).toBe(component.buildIdentifier(msg.product));
    component.bag = [];
    msg.status = 'fail';
    component.chooseMessageHandler(msg);
    expect(component.bag[0]).toBeFalsy();
  });

it('should handle remove from bag Message', () => {
    const msg: BagResponse = {
      actionType: 'remove',
      category: 'bag',
      product: { colorId: '01', productId: '23423', sizeId: 'SM003' },
      status: 'fail'
    };
    component.add(component.buildIdentifier(msg.product));
    component.chooseMessageHandler(msg);
    expect(component.bag[0]).toBeTruthy();
    msg.status = 'success';
    component.chooseMessageHandler(msg);
    expect(component.bag[0]).toBeFalsy();
  });