def test_libgwyfile_function_returns_null(self):
"""
Returns empty list if libgwyfile function returns NULL
"""
enum_graphs = self.mock_lib.gwyfile_object_container_enumerate_graphs
enum_graphs.return_value = ffi.NULL
ids = GwyContainer._get_graph_ids(self.gwyfile)
self.assertEqual(ids, [])
def test_libgwyfile_function_returns_non_zero_channels(self):
"""
Returns list of graph ids if their number is not zero
"""
self.mock_lib.gwyfile_object_container_enumerate_graphs.side_effect = (
self._side_effect_non_zero_graphs)
ids = GwyContainer._get_graph_ids(self.gwyfile)
self.assertEqual(ids, [1, 2])