问题描述
我正在尝试使用 pytest 和 pytest_mock 运行以下测试
I'm trying to run the following test using pytest and pytest_mock
def rm(filename): helper(filename, 5) def helper(filename): pass def test_unix_fs(mocker): mocker.patch('module.helper') rm('file') helper.assert_called_once_with('file', 5)
但我得到异常 AttributeError: 'function' object has no attribute 'assert_called_once_with'
我做错了什么?
推荐答案
你不能在 vanilla 函数上执行 .assert_call_once_with 函数:你首先需要包装它与 mock.create_autospec代码> 装饰器.比如:
You can not perform a .assert_called_once_with function on a vanilla function: you first need to wrap it with the mock.create_autospec decorator. So for instance:
import unittest.mock as mock def rm(filename): helper(filename, 5) def helper(filename): pass helper = mock.create_autospec(helper) def test_unix_fs(mocker): mocker.patch('module.helper') rm('file') helper.assert_called_once_with('file', 5)
或者更优雅:
import unittest.mock as mock def rm(filename): helper(filename, 5) @mock.create_autospec def helper(filename): pass def test_unix_fs(mocker): mocker.patch('module.helper') rm('file') helper.assert_called_once_with('file', 5)
请注意,断言将失败,因为您仅使用 'file' 调用它.所以一个有效的测试是:
Note that the assertion will fail, since you call it only with 'file'. So a valid test would be:
import unittest.mock as mock def rm(filename): helper(filename, 5) @mock.create_autospec def helper(filename): pass def test_unix_fs(mocker): mocker.patch('module.helper') rm('file') helper.assert_called_once_with('file')
编辑:如果函数是在某个模块中定义的,您可以将其包装在本地的装饰器中.例如:
EDIT: In case the function is defined in some module, you can wrap it in a decorator locally. For example:
import unittest.mock as mock from some_module import some_function some_function = mock.create_autospec(some_function) def test_unix_fs(mocker): some_function('file') some_function.assert_called_once_with('file')