def test_gcd_b_equal_to_zero(self):
with self.assertRaises(ValueError):
gcd(2, 0)
def test_gcd_a_equal_to_b(self):
expected = 2
actual = gcd(2, 2)
self.assertEqual(expected, actual)
def test_gcd_both_negative(self):
expected = -2
actual = gcd(-4, -2)
self.assertEqual(expected, actual)
def test_gcd_a_negative_b_positive(self):
expected = 2
actual = gcd(-4, 2)
self.assertEqual(expected, actual)
def test_gcd_a_positive_b_negative(self):
expected = -2
actual = gcd(4, -2)
self.assertEqual(expected, actual)
def test_gcd_b_greater_than_a(self):
expected = 2
actual = gcd(2, 4)
self.assertEqual(expected, actual)
def test_gcd_a_greater_than_b(self):
expected = 2
actual = gcd(4, 2)
self.assertEqual(expected, actual)