def test_raises_valueerror_when_attempting_darken_with_invalid_type(
dummy_image: Image, level: int):
with pytest.raises(ValueError):
dummy_image.darken(level=level)
def test_darken_operation_respects_maximum_grayscale(dummy_image: Image):
p = GrayPixel(100)
dummy_image.set_pixel(1, 1, p)
darken_img = dummy_image.darken(200)
assert not any(val.value > 0 for row in darken_img.values for val in row)
