def test_search(self):
sample_linked_list = linked_list.Linked_list()
for i in range(10):
sample_linked_list.insert(i)
self.assertEqual(sample_linked_list.head.key, 9)
self.assertEqual(sample_linked_list.head.next.next.key, 7)
self.assertEqual(sample_linked_list.head.next.next.next.next.key, 5)
def test_pop():
"""Test pop method with a populated and empty list.
Validate pop output and removal"""
a = ll.Linked_list()
a.insert("Mark")
a.insert("Henry")
assert a.pop() == "Henry"
# Confirming that Mark is the new Head and has no pointer
assert "Mark" == a.head.value
assert a.head.pointer is None
b = ll.Linked_list()
# Confirm Attribute error with pop from empty list
with pytest.raises(AttributeError):
assert b.pop() is None
def test_delete(self):
sample_linked_list = linked_list.Linked_list()
for i in range(10):
sample_linked_list.insert(i)
sample_linked_list.delete(9)
self.assertEqual(sample_linked_list.head.key, 8)
sample_linked_list.delete(5)
self.assertEqual(sample_linked_list.head.next.next.next.next.key, 3)
def test_insert(self):
sample_linked_list = linked_list.Linked_list()
sample_linked_list.insert(3)
self.assertEqual(sample_linked_list.head.key, 3)
sample_linked_list.insert(5)
self.assertEqual(sample_linked_list.head.key, 5)
self.assertEqual(sample_linked_list.head.next.key, 3)
sample_linked_list.insert(7)
self.assertEqual(sample_linked_list.head.key, 7)
self.assertEqual(sample_linked_list.head.next.key, 5)
self.assertEqual(sample_linked_list.head.next.next.key, 3)
def test_str():
"""Test of string formatting with integers and strings."""
a = ll.Linked_list()
assert str(a) == "()"
a.insert("Mark")
a.insert("Henry")
a.insert(1232)
a.insert("Efrain")
a.insert("Last")
a.insert(4545)
assert str(a) == "(4545, 'Last', 'Efrain', 1232, 'Henry', 'Mark')"
# Test string evaluates to a tuple literal
assert eval(str(a)) == (4545, 'Last', 'Efrain', 1232, 'Henry', 'Mark')
def test_insert():
"""Test insert by adding node to empty list and
adding list with exisiting nodes."""
# Test insert into empty list.
a = ll.Linked_list()
assert a.head is None
a.insert("Mark")
assert "Mark" == a.head.value
assert a.head.pointer is None
# Test insert into populated list.
a.insert("Henry")
assert "Henry" == a.head.value
assert "Mark" == a.head.pointer.value
def test_search():
"""Return the node containing value in the list, if present, else None."""
a = ll.Linked_list()
a.insert("Mark")
a.insert("Henry")
a.insert(1232)
a.insert("Efrain")
a.insert("Last")
a.insert(4545)
assert a.search("Mark").value == "Mark"
assert a.search(1232).value == 1232
# Test ability to find first node value
assert a.search(4545).value == 4545
# Test search for non-existing item
assert a.search("George") is None
def test_size():
"""Test Size with pop and remove commands."""
a = ll.Linked_list()
a.insert("Mark")
a.insert("Henry")
a.insert("Efrain")
a.insert("Last")
a.display()
assert a.size() == 4
a.remove(a.search("Henry"))
assert a.size() == 3
a.pop()
assert a.size() == 2
a.pop()
assert a.size() == 1
a.pop()
assert a.size() == 0
def test_remove():
"""Test removal of nodes."""
# Test remove of node in middle of linked list
a = ll.Linked_list()
a.insert("Henry")
a.insert("Efrain")
a.insert("Last")
a.remove(a.search("Henry"))
assert a.size() == 2
assert str(a) == "('Last', 'Efrain')"
# Test removal of the first node
a.remove(a.search("Last"))
assert a.size() == 1
assert str(a) == "('Efrain')"
# Test removal of last node
a.remove(a.search("Efrain"))
assert a.size() == 0
assert str(a) == "()"
def test_traverse(self):
sample_linked_list = linked_list.Linked_list()
for i in range(10):
sample_linked_list.insert(i)
self.assertEqual(sample_linked_list.traverse(),
[9, 8, 7, 6, 5, 4, 3, 2, 1, 0])
def test_init():
"""Test link_list class constructor."""
a = ll.Linked_list()
assert isinstance(a, ll.Linked_list)
