def test_errors_if_target_does_not_exist_in_large_tree(self):
tree = Tree('parent', [
Tree('x', [Tree('kid-0'), Tree('kid-1')]),
Tree('sibling-0'),
Tree('sibling-1')
])
with self.assertRaisesWithMessage(ValueError):
tree.fromPov('nonexistent')
def test_can_reroot_complex_tree_with_cousins(self):
tree = Tree('grandparent', [
Tree('parent', [
Tree('x', [
Tree('kid-0'),
Tree('kid-1')
]),
Tree('sibling-0'),
Tree('sibling-1')
]),
Tree('uncle', [
Tree('cousin-0'),
Tree('cousin-1')
])
])
expected = Tree('x', [
Tree('kid-0'),
Tree('kid-1'),
Tree('parent', [
Tree('sibling-0'),
Tree('sibling-1'),
Tree('grandparent', [
Tree('uncle', [
Tree('cousin-0'),
Tree('cousin-1')
])
])
])
])
self.assertTreeEquals(tree.fromPov('x'), expected)
def test_can_reroot_a_tree_with_new_root_deeply_nested(self):
tree = Tree('level-0', [
Tree('level-1', [Tree('level-2', [Tree('level-3', [Tree('x')])])])
])
expected = Tree('x', [
Tree('level-3',
[Tree('level-2', [Tree('level-1', [Tree('level-0')])])])
])
self.assertTreeEquals(tree.fromPov('x'), expected)
def test_can_reroot_tree_with_parent_and_one_sibling(self):
tree = Tree('parent', [
Tree('x'),
Tree('sibling')
])
expected = Tree('x', [
Tree('parent', [
Tree('sibling')
])
])
self.assertTreeEquals(tree.fromPov('x'), expected)
def test_moves_children_of_new_root_to_same_level_as_former_parent(self):
tree = Tree('parent', [
Tree('x', [
Tree('kid-0'),
Tree('kid-1')
])
])
expected = Tree('x', [
Tree('parent'),
Tree('kid-0'),
Tree('kid-1')
])
self.assertTreeEquals(tree.fromPov('x'), expected)
def test_errors_if_target_does_not_exist_in_singleton_tree(self):
tree = Tree('x')
with self.assertRaisesWithMessage(ValueError):
tree.fromPov('nonexistent')
def test_singleton_returns_same_tree(self):
tree = Tree('x')
self.assertTreeEquals(tree.fromPov('x'), tree)
