def test_tree(self):
"""Test that the tree structure is as expected: all nodes have correct parent and children.
"""
tree = Tree()
root = tree.add_root(1)
left = root.add_left(2)
right = root.add_right(3)
self.assertEqual(None, root.parent)
self.assertEqual(root, tree.root)
self.assertEqual(left, tree.root.left)
self.assertEqual(right, tree.root.right)
self.assertEqual(root, left.parent)
self.assertEqual(root, right.parent)
self.assertEqual(None, left.left)
self.assertEqual(None, left.right)
self.assertEqual(None, right.left)
self.assertEqual(None, right.right)
def breadth_first_test(self):
"""Test that the breadth first traversal returns nodes in the correct order: left to right, top to bottom;
processing all nodes on a level from left to right before proceeding down a level.
E.g. 1
2 3
4 5 6 7
"""
tree = Tree()
root = tree.add_root(1)
left = root.add_left(2)
right = root.add_right(3)
left.add_left(4)
left.add_right(5)
right.add_left(6)
right.add_right(7)
items = []
for item in tree.breadth_first():
items.append(item.data)
self.assertEqual(items, [1, 2, 3, 4, 5, 6, 7])