def test_add_node_second():
ll = LinkedList()
ll.add_node(3)
ll.add_node('hello')
first_node = ll.base.next_node
second_node = first_node.next_node
assert first_node.value == 3
assert first_node.next_node is not None
assert second_node.value == 'hello'
assert second_node.next_node is None
def test_add_node_none():
ll = LinkedList()
ll.add_node(3)
nodes_before = count_nodes(ll)
ll.add_node(None)
nodes_after = count_nodes(ll)
assert nodes_before == nodes_after
first_node = ll.base.next_node
assert first_node.value == 3
assert first_node.next_node is None
def test():
l = LinkedList()
l.add_node(10)
l.add_node(3)
l.add_node(7)
l.add_node(9)
# List: base -> 10 -> 3 -> 7 -> 9
l = update_list(l)
# List: base -> 3 -> 9
assert isinstance(l, LinkedList)
assert isinstance(l.base, Node)
assert l.base.value is None
assert l.base.next_node is not None
assert l.count_nodes() == 2
p = l.base.next_node
assert p.value == 3
p = p.next_node
assert p.value == 9
p = p.next_node
assert p is None
def create_list():
l = LinkedList()
l.add_node(10)
l.add_node(3)
l.add_node(7)
l.add_node(9)
return l
def test_remove_node_last():
ll = LinkedList()
ll.add_node(3)
ll.add_node('hello')
ll.add_node(4)
ll.add_node(5)
ll.add_node(6)
# list: 3 'hello' 4 5 6
nodes_before = count_nodes(ll)
ll.remove_node(6)
nodes_after = count_nodes(ll)
assert nodes_after == nodes_before - 1
last = ll.base
while last.next_node is not None:
last = last.next_node
assert last.value == 5
def test_remove_node_inexisting():
ll = LinkedList()
ll.add_node(3)
ll.add_node('hello')
ll.add_node(5)
# list: 3 'hello' 5
nodes_before = count_nodes(ll)
ll.remove_node(4)
nodes_after = count_nodes(ll)
assert nodes_before == nodes_after
def test_remove_node_duplicate():
ll = LinkedList()
ll.add_node(3)
ll.add_node('hello')
ll.add_node(5)
ll.add_node(5)
# list: 3 'hello' 5 5
nodes_before = count_nodes(ll)
ll.remove_node(5)
nodes_after = count_nodes(ll)
assert nodes_after == nodes_before - 1
def test_remove_node_first():
ll = LinkedList()
ll.add_node(3)
ll.add_node('hello')
ll.add_node(5)
# list: 3 'hello' 5
nodes_before = count_nodes(ll)
ll.remove_node(3)
nodes_after = count_nodes(ll)
assert nodes_after == nodes_before - 1
p = ll.base.next_node
assert p.value == 'hello'
p = p.next_node
assert p.value == 5
assert p.next_node is None
def test_add_node_first():
ll = LinkedList()
ll.add_node(3)
assert ll.base.next_node is not None
assert ll.base.next_node.value == 3
def test_count_nodes():
ll = LinkedList()
ll.add_node('hello')
ll.add_node(5)
assert ll.count_nodes() == 2