Angular unit test - how to test reactive form reset method?

Question

I'm trying to test this method:

doResetForm(){
   this.form.reset();
}

so I tried:

it('should reset the form', () => {
   const spyformReset = jest.spyOn(component.form, 'reset');
   
   fixture.detectChanges();
   component.doResetForm();
   expect(spyformReset).toHaveBeenCalled();
}

but I'm getting the error:

Cannot spyon on a primitive value, undefined give

Answer 1

You can use spyOn to mock the method.

const spyformReset = spyOn(component.form, 'reset').and.callThrough();
component.doResetForm();
expect(spyformReset).toHaveBeenCalled();