Here is a code snippet on how to test open
built-in function:
Code to test:
def my_function(self, id: int) -> None: file_path = 'path/to/files/{}.txt'.format(id) with open(file_path, 'w') as f: f.write('< My data >')
Unit test:
def test_my_function(self): _open = mock.mock_open() with mock.patch('my_project.scripts.my_script.open', _open, create=True): # noqa my_function(1) _open.assert_called_with('path/to/files/123.txt', 'w') fp = _open.return_value.__enter__.return_value fp.write.assert_called_with('< My data >')
Happy unit testing.