def test_all_match(self):
self.assertEqual(U.first(always, ''), None)
self.assertEqual(U.first(always, 'abc'), 'a')
def test_with_predicate(self):
self.assertEqual(U.first(is_alpha, ''), None)
self.assertEqual(U.first(is_alpha, 'abc'), 'a')
self.assertEqual(U.first(is_alpha, '123abc'), 'a')
self.assertEqual(U.first(is_alpha, ' abc'), 'a')
def test_no_match(self):
self.assertEqual(U.first(never, ''), None)
self.assertEqual(U.first(never, 'abc'), None)