def test_validate_returns_correct_node_with_correct_parameters(self):
pl = PositionalList()
# setup a correctly referenced _Node:
expected_node = PositionalList._Node('foo', pl._header, pl._trailer)
pl._header._next = expected_node
pl._trailer._prev = expected_node
good_position = PositionalList.Position(pl, expected_node)
result_node = pl._validate(good_position)
self.assertIs(result_node, expected_node)
def test_replace_validates_replaces_returns_old_element(self):
pl = PositionalList()
original_element = 'foo'
new_element = 'bar'
node = PositionalList._Node(original_element, None, None)
pl._validate = MagicMock(return_value=node)
position = PositionalList.Position(pl, node)
result_element = pl.replace(position, new_element)
pl._validate.assert_called_with(position)
self.assertIs(result_element, original_element)
self.assertIs(node._element, new_element)
def test_delete_validates_and_calls_delete_node_on_position(self):
pl = PositionalList()
expected_element = 'foo'
node = PositionalList._Node(expected_element, None, None)
pl._validate = MagicMock(return_value=node)
pl._delete_node = MagicMock(return_value=expected_element)
position = PositionalList.Position(pl, node)
result_element = pl.delete(position)
pl._validate.assert_called_with(position)
pl._delete_node.assert_called_with(node)
self.assertIs(result_element, expected_element)