import unittest

from main import array_diff

class Test_array_diff(unittest.TestCase):





    def test(self):

        self.subTest("Basic tests")
        self.assertEqual(array_diff([1, 2], [1]), [2], "a was [1,2], b was [1], expected [2]")
        self.assertEqual(array_diff([1, 2, 2], [1]), [2, 2], "a was [1,2,2], b was [1], expected [2,2]")
        self.assertEqual(array_diff([1, 2, 2], [2]), [1], "a was [1,2,2], b was [2], expected [1]")
        self.assertEqual(array_diff([1, 2, 2], []), [1, 2, 2], "a was [1,2,2], b was [], expected [1,2,2]")
        self.assertEqual(array_diff([], [1, 2]), [], "a was [], b was [1,2], expected []")

if __name__ == '__main__':
    unittest.main()