def test_get_elements(self):
l = DoublyLinkedList()
self.assertEqual(l.get_elements(), 0)
for i in range(100):
l.add(i)
self.assertEqual(l.get_elements(), (i + 1))
for i in range(100):
l.delete(i)
self.assertEqual(l.get_elements(), (99 - i))
def test_is_empty(self):
l = DoublyLinkedList()
self.assertTrue(l.is_empty())
for i in range(10):
l.add(i)
self.assertFalse(l.is_empty())
for i in range(10):
l.delete(i)
self.assertTrue(l.is_empty())
def test_delete(self):
l = DoublyLinkedList()
self.assertRaises(ValueError, l.delete, 0)
for i in range(5):
l.add(i)
self.assertTrue(l.contains(i))
l.delete(2)
self.assertFalse(l.contains(2))
self.assertEqual(l.index_of(1), 1)
self.assertEqual(l.index_of(3), 2)
self.assertEqual(l.get_elements(), 4)
l.delete(0)
self.assertFalse(l.contains(0))
self.assertEqual(l.get_first(), 1)
self.assertEqual(l.index_of(3), 1)
self.assertEqual(l.get_elements(), 3)
l.delete(4)
self.assertFalse(l.contains(4))
self.assertEqual(l.get_last(), 3)
self.assertEqual(l.get_first(), 1)
self.assertRaises(ValueError, l.index_of, 4)
self.assertEqual(l.get_elements(), 2)
l.delete(1)
self.assertFalse(l.contains(1))
self.assertEqual(l.get_first(), 3)
self.assertEqual(l.get_last(), 3)
self.assertEqual(l.get_elements(), 1)
l.delete(3)
self.assertTrue(l.is_empty())
self.assertEqual(l.get_elements(), 0)
