模仿Pathlib write_text？

Question

我正在编写一个简单的函数，通过一些转换和yaml将一个字典写到磁盘上。测试发生了什么最简单的方法是捕获Path(file_name).write_text(text_to_write)的输出。但是我很难准确地理解我需要做什么来捕获这些内容。

def test_path_write():
    with mock.patch('Path.write_text', return_value=None):
        function_that_uses_path_write_text()
        assert 'Content I would like to be in the file' in SOME_KIND_OF_CAPTURE

你知道如何将一些东西放到SOME_KIND_OF_CAPTURE中，我可以用它来测试吗？

Answer 1

使用pytest，下面是我所做的：

def test_writer(mocker):
    mocker.patch.object(Path, "write_text")

    [...]

    written_content = Path.write_text.call_args_list[0][0][0]

Answer 2

你在找下面这样的东西吗？

with patch.object(Path, 'write_text') as patch_path:
    data_to_write = 'Something'
    patch_path.return_value = data_to_write

    path = Path('some/path')
    res = path.write_text(data_to_write)

print(res)