def test_set_at_can_set_a_leaf(example_tree):
set_at(example_tree, ('foo', 'bar', 'baz'), sentinel.new_value)
for path, value in walk(example_tree):
if path == ('foo', 'bar', 'baz'):
assert value == sentinel.new_value
else:
assert value != sentinel.new_value
def structural_copy(tree):
result = Tree()
r = Path(result)
for path, leaf in walk(tree):
set_at(r, path, leaf)
return result
def test_set_at_non_existent_path(example_tree):
with pytest.raises(AttributeError):
set_at(example_tree, ('does', 'not', 'exist'), sentinel.new_value)
def test_set_at_non_existent_leaf(example_tree):
pre_exisiting = list(walk(example_tree))
set_at(example_tree, ('foo', 'bar', 'new_node'), sentinel.new_value)
assert sorted(walk(example_tree)) == sorted(pre_exisiting + [(('foo', 'bar', 'new_node'), sentinel.new_value)])
def test_set_at_empty_path_in_empty_tree():
with pytest.raises(ValueError):
set_at(Tree(), [], sentinel.new_value)
def test_set_at_empty_path(example_tree):
with pytest.raises(ValueError):
set_at(example_tree, [], sentinel.new_value)
def test_set_at_can_overwrite_a_subtree(example_tree):
set_at(example_tree, ('foo', 'bar'), sentinel.new_value)
assert sorted(walk(example_tree)) == sorted([(('foo', 'bar',), sentinel.new_value),
(('foo', 'lar', 'baz',), sentinel.foolarbaz),
(('moo', 'bar', 'baz',), sentinel.moobarbaz), ])
