def test_stack_is_empty(self):
s = util.Stack()
self.assertTrue(s.is_empty())
s.push(1)
self.assertFalse(s.is_empty())
s.pop()
self.assertTrue(s.is_empty())
def test_accepts_variable_inputs(self):
s = util.Stack()
s.push(*[2, 4, 6])
actual = []
for elem in s:
actual.append(elem)
self.assertListEqual(actual, [6, 4, 2])
def test_evaluates_to_false_when_empty(self):
s = util.Stack()
s.push(5)
self.assertTrue(s)
s.pop()
self.assertFalse(s)
def test_gets_size(self):
s = util.Stack()
s.push(1, 3, 5, 7, 9)
self.assertEqual(len(s), 5)