def test_faketree_add_assignment(patch, fake_tree, block):
patch.object(FakeTree, 'assignment')
block.child.return_value = None
result = fake_tree.add_assignment('value')
FakeTree.assignment.assert_called_with('value')
assert block.children == [FakeTree.assignment(), block.child()]
assert result == FakeTree.assignment()
def test_faketree_add_assignment_more_children(patch, fake_tree, block):
patch.object(FakeTree, 'assignment')
fake_tree.add_assignment('value')
expected = [block.child(), FakeTree.assignment(), block.child()]
assert block.children == expected