def test_chaining_valid_operations(self):
a = Vector(1, 2, 3)
b = Vector(1, 2, 3)
# chain addition and subtraction
chain1 = a + b - a + b
chain1_expected_result = Vector(2, 4, 6)
self.assertEqual(chain1_expected_result, chain1)
# chain scalar multiplication and dot product
chain2 = a * b * 5 * a
chain2_expected_result = Vector(70, 140, 210)
self.assertEqual(chain2_expected_result, chain2)
# chain dot product, scalar multiplication, reversal
chain3 = (a * b * 5 * a).smul(0.5).reversed()
chain3_expected_result = Vector(-35, -70, -105)
self.assertEqual(chain3_expected_result, chain3)
# chain cross product, vector addition,
# vector subtraction, scalar multiplication
a = Vector(3, -3, 1)
b = Vector(4, 9, 2)
chain4 = a.crossmul(b).smul(-1).subtract(b).add(a)
chain4_expected_result = Vector(14, -10, -40)
self.assertEqual(chain4_expected_result, chain4)
def test_cross_product(self):
a = Vector(3, -3, 1)
b = Vector(4, 9, 2)
expected_cross_product = Vector(-15, -2, 39)
self.assertEqual(expected_cross_product, a.crossmul(b))
