def test_get_size(self):
stack = LinkedListStack()
expected = 0
actual = stack.get_size()
self.assertEqual(expected, actual)
stack.push(42)
stack.push(42)
stack.push(42)
stack.pop()
expected = 2
actual = stack.get_size()
self.assertEqual(expected, actual)
def test_pop(self):
stack = LinkedListStack()
self.assertIsNone(stack.pop())
expected = 42
stack.push(expected + 2)
stack.push(expected + 1)
stack.push(expected)
actual = stack.pop()
self.assertEqual(expected, actual)
actual = stack.pop()
self.assertEqual(expected + 1, actual)
actual = stack.pop()
self.assertEqual(expected + 2, actual)
def test_push(self):
stack = LinkedListStack()
expected = 42
stack.push(expected)
stack.push(expected + 1)
actual = stack.pop()
self.assertEqual(expected + 1, actual)
def test_iterator(self):
stack = LinkedListStack()
expected = 42
stack.push(expected)
stack.push(expected + 1)
iterator = stack.__iter__()
actual1 = iterator.__next__()
actual2 = iterator.__next__()
self.assertEqual(expected + 1, actual1)
self.assertEqual(expected, actual2)
def test_is_empty(self):
stack = LinkedListStack()
actual = stack.is_empty()
self.assertTrue(actual)
stack.push(42)
actual = stack.is_empty()
self.assertFalse(actual)
def test_str(self):
stack = LinkedListStack()
stack.push(42)
stack.push(43)
stack.push(44)
expected = "44\n43\n42\n"
actual = str(stack)
self.assertEqual(expected, actual)
def test_clear(self):
stack = LinkedListStack()
self.assertTrue(stack.is_empty())
expected = 42
stack.push(expected + 2)
stack.push(expected + 1)
stack.push(expected)
self.assertFalse(stack.is_empty())
self.assertEqual(3, stack.get_size())
stack.clear()
self.assertTrue(stack.is_empty())
self.assertEqual(0, stack.get_size())
self.assertIsNone(stack.pop())
def test_peek(self):
stack = LinkedListStack()
self.assertIsNone(stack.peek())
expected = 42
stack.push(expected + 2)
stack.push(expected + 1)
stack.push(expected)
self.assertEqual(3, stack.get_size())
actual = stack.peek()
self.assertEqual(expected, actual)
self.assertEqual(3, stack.get_size())
actual = stack.pop()
self.assertEqual(expected, actual)