def test_next(self):
singly_linked_list = SinglyLinkedList()
it = singly_linked_list.iterator()
with self.assertRaises(NoSuchElementException):
it.next()
singly_linked_list.insert_last("element 1")
singly_linked_list.insert_last("element 2")
singly_linked_list.insert_last("element 3")
it = singly_linked_list.iterator()
self.assertEqual(it.next(), "element 1")
self.assertEqual(it.next(), "element 2")
self.assertEqual(it.next(), "element 3")
with self.assertRaises(NoSuchElementException):
it.next()
def test_has_next(self):
singly_linked_list = SinglyLinkedList()
it = singly_linked_list.iterator()
self.assertFalse(it.has_next())
singly_linked_list.insert_last("element 1")
singly_linked_list.insert_last("element 2")
singly_linked_list.insert_last("element 3")
it = singly_linked_list.iterator()
self.assertTrue(it.has_next())
it.next()
self.assertTrue(it.has_next())
it.next()
self.assertTrue(it.has_next())
it.next()
self.assertFalse(it.has_next())
def test_rewind(self):
singly_linked_list = SinglyLinkedList()
singly_linked_list.insert_last("element 1")
singly_linked_list.insert_last("element 2")
singly_linked_list.insert_last("element 3")
it = singly_linked_list.iterator()
self.assertEqual(it.next(), "element 1")
self.assertEqual(it.next(), "element 2")
it.rewind()
self.assertEqual(it.next(), "element 1")
class TestSinglyLinkedList(unittest.TestCase):
def setUp(self):
self.list = SinglyLinkedList()
def add_elements(self, quantity, shift=0):
for i in range(quantity):
self.list.insert_last(f"element {i+1+shift}")
def remove_elements(self, quantity):
for _ in range(quantity):
self.list.remove_last()
def test_is_empty(self):
self.assertTrue(self.list.is_empty())
self.add_elements(1)
self.assertFalse(self.list.is_empty())
def test_size(self):
self.assertEqual(self.list.size(), 0)
self.add_elements(3)
self.assertEqual(self.list.size(), 3)
self.remove_elements(3)
self.assertEqual(self.list.size(), 0)
def test_get_first(self):
with self.assertRaises(EmptyListException):
self.list.get_first()
self.add_elements(3)
self.assertEqual(self.list.get_first(), "element 1")
def test_get_last(self):
with self.assertRaises(EmptyListException):
self.list.get_last()
self.add_elements(3)
self.assertEqual(self.list.get_last(), "element 3")
def test_get(self):
with self.assertRaises(EmptyListException):
self.list.get(0)
self.add_elements(5)
self.assertEqual(self.list.get(2), "element 3")
def test_find(self):
self.assertEqual(self.list.find("empty list"), -1)
self.add_elements(5)
self.assertEqual(self.list.find("element 3"), 2)
self.assertEqual(self.list.find("missing element"), -1)
def test_insert_first(self):
self.list.insert_first("element")
self.assertEqual(self.list.get_first(), "element")
self.list.make_empty()
self.add_elements(5)
self.assertNotEqual(self.list.get_first(), "element")
self.list.insert_first("element")
self.assertEqual(self.list.get_first(), "element")
def test_insert_last(self):
self.list.insert_first("element")
self.assertEqual(self.list.get_last(), "element")
self.list.make_empty()
self.add_elements(5)
self.assertNotEqual(self.list.get_last(), "element")
self.list.insert_last("element")
self.assertEqual(self.list.get_last(), "element")
def test_insert(self):
with self.assertRaises(InvalidPositionException):
self.list.insert("element X", 42)
self.list.insert("element 1", 0)
self.assertEqual(self.list.get_first(), "element 1")
self.add_elements(4, shift=1)
self.list.insert("element X", 2)
self.assertEqual(self.list.get(2), "element X")
self.list.insert("last element", self.list.size())
self.assertEqual(self.list.get_last(), "last element")
with self.assertRaises(InvalidPositionException):
self.list.insert("element bean", 42)
def test_remove_first(self):
with self.assertRaises(EmptyListException):
self.list.remove_first()
self.add_elements(5)
self.list.remove_first()
self.assertEqual(self.list.get_first(), "element 2")
def test_remove_first_single_element(self):
self.add_elements(1)
self.assertEqual(self.list.remove_first(), "element 1")
with self.assertRaises(EmptyListException):
self.list.remove_first()
with self.assertRaises(EmptyListException):
self.list.get(0)
with self.assertRaises(EmptyListException):
self.list.get_last()
with self.assertRaises(EmptyListException):
self.list.get_first()
self.assertTrue(self.list.is_empty())
self.assertEqual(self.list.find("element 1"), -1)
self.add_elements(1)
self.assertEqual(self.list.get_first(), "element 1")
self.assertEqual(self.list.get_last(), "element 1")
self.assertEqual(self.list.remove_first(), "element 1")
def test_remove_last(self):
with self.assertRaises(EmptyListException):
self.list.remove_last()
self.add_elements(5)
self.list.remove_last()
self.assertEqual(self.list.get_last(), "element 4")
def test_remove_last_two_elements(self):
self.add_elements(2)
self.assertEqual(self.list.remove_last(), "element 2")
def test_remove_last_single_element(self):
self.list.make_empty()
self.add_elements(1)
self.assertEqual(self.list.remove_last(), "element 1")
with self.assertRaises(EmptyListException):
self.list.remove_last()
with self.assertRaises(EmptyListException):
self.list.get(0)
with self.assertRaises(EmptyListException):
self.list.get_last()
with self.assertRaises(EmptyListException):
self.list.get_first()
self.assertTrue(self.list.is_empty())
self.assertEqual(self.list.find("element 1"), -1)
self.add_elements(1)
self.assertEqual(self.list.get_first(), "element 1")
self.assertEqual(self.list.get_last(), "element 1")
self.assertEqual(self.list.remove_last(), "element 1")
def test_remove(self):
with self.assertRaises(InvalidPositionException):
self.list.remove(1)
self.add_elements(5)
with self.assertRaises(InvalidPositionException):
self.list.remove(6)
self.assertEqual(self.list.remove(0), "element 1")
self.assertEqual(self.list.remove(2), "element 4")
self.assertEqual(self.list.remove(2), "element 5")
def test_remove_single_element(self):
self.list.make_empty()
self.add_elements(1)
self.assertEqual(self.list.remove(0), "element 1")
with self.assertRaises(InvalidPositionException):
self.list.remove(0)
with self.assertRaises(EmptyListException):
self.list.get(0)
with self.assertRaises(EmptyListException):
self.list.get_last()
with self.assertRaises(EmptyListException):
self.list.get_first()
self.assertTrue(self.list.is_empty())
self.assertEqual(self.list.find("element 1"), -1)
self.add_elements(1)
self.assertEqual(self.list.get_first(), "element 1")
self.assertEqual(self.list.get_last(), "element 1")
self.assertEqual(self.list.remove(0), "element 1")
def test_make_empty(self):
self.assertTrue(self.list.is_empty())
self.add_elements(5)
self.assertFalse(self.list.is_empty())
self.list.make_empty()
self.assertTrue(self.list.is_empty())
def test_iterator(self):
self.assertIsInstance(self.list.iterator(), Iterator)
self.assertIsInstance(self.list.iterator(), SinglyLinkedListIterator)