def test_delta_should_return_2_element_tuple(self): point = EarthPoint(x=1, y=2, altitude=5) self.assertEqual(tuple, type(point.delta(0, 0))) self.assertEqual(2, len(point.delta(0, 0)))
def test_delta_should_apply_negative_increase_to_y(self): point = EarthPoint(x=1, y=2, altitude=5) delta = point.delta(5, -3) self.assertEqual(2 - 3, delta[1])
def test_delta_should_apply_nil_increase_to_y(self): point = EarthPoint(x=1, y=2, altitude=5) delta = point.delta(0, 0) self.assertEqual(2, delta[1])
def test_delta_should_apply_negative_increase_to_x(self): point = EarthPoint(x=1, y=2, altitude=5) delta = point.delta(-5, 2) self.assertEqual(1 - 5, delta[0])