def test_find_right_minimum_returns_root_node_when_no_rights():
root_node = BinaryTreeNode(5)
child_node = BinaryTreeNode(3)
tree = BinaryTree(root_node)
tree.insert_node(child_node)
result = tree.find_right_minimum(root_node)
assert result == root_node
def test_find_right_minimum_returns_right_minimum_in_shallow_example():
root_node = BinaryTreeNode(5)
left_node = BinaryTreeNode(3)
right_node = BinaryTreeNode(7)
tree = BinaryTree(root_node)
tree.insert_node(left_node)
tree.insert_node(right_node)
result = tree.find_right_minimum(root_node)
assert result == right_node
def test_find_right_minimum_returns_right_minimum_in_deep_example():
root_node = BinaryTreeNode(5)
left_node = BinaryTreeNode(3)
right_node = BinaryTreeNode(9)
deep_right_right_node = BinaryTreeNode(8)
deep_right_left_node = BinaryTreeNode(11)
tree = BinaryTree(root_node)
tree.insert_node(left_node)
tree.insert_node(right_node)
tree.insert_node(deep_right_left_node)
tree.insert_node(deep_right_right_node)
result = tree.find_right_minimum(root_node)
assert result == deep_right_right_node