def test_insert_with_7_items(self):
# Create a complete binary search tree of 7 items in level-order
items = [4, 2, 6, 1, 3, 5, 7]
tree = BinarySearchTree()
for item in items:
tree.insert(item)
assert tree.root.data == 4
def test_size(self):
tree = BinarySearchTree()
assert tree.size == 0
tree.insert('B')
assert tree.size == 1
tree.insert('A')
assert tree.size == 2
tree.insert('C')
assert tree.size == 3
def test_insert_with_3_items(self):
# Create a complete binary search tree of 3 items in level-order
tree = BinarySearchTree()
tree.insert(2)
assert tree.root.data == 2
tree.insert(1)
assert tree.root.data == 2
tree.insert(3)
assert tree.root.data == 2