問題描述

我有一個專有的存儲庫格式，我正在嘗試開發一個 Python 模塊來處理這些存儲庫.回購格式如下:

I have a proprietary repository format and I'm trying to develop a Python module to process these repositories. Repo format goes as:

/home/X/
       |
       + alpha/
       |
       + beta/
       |
       + project.conf

這里，X 是一個項目.alpha 和 beta 是本項目中的文件夾，它們代表本項目中的組.group 是這個 repo 中的一個容器，它所代表的內容實際上與這個問題無關.repo X 在其根級別也有文件；project.conf 就是此類文件的一個示例.

Here, X is a project. alpha and beta are folders inside this project and they represent groups in this project. A group is a container in this repo and what it represents is really not relevant for this question. The repo X also has files in its root level; project.conf is an example of such a file.

我有一個名為Project 的類，它抽象出X 等項目.Project 類有一個 load() 方法，用于構建內存中的表示.

I have a class called Project that abstracts projects such as X. The Project class has a method load() that builds an in-memory representation.

class Project(object):

    def load(self):
        for entry in os.listdir(self.root):
            path = os.path.join(self.root, entry)
            if os.path.isdir(path):
                group = Group(path)
                self.groups.append(group)
                group.load()
            else:
                # process files ...

要通過模擬文件系統對 load() 方法進行單元測試，我有:

To unit test the load() method by mocking the file system, I have:

import unittest
from unittest import mock
import Project

class TestRepo(unittest.TestCase):

    def test_load_project(self):
        project = Project("X")

        with mock.patch('os.listdir') as mocked_listdir:
            mocked_listdir.return_value = ['alpha', 'beta', 'project.conf']
            project.load()
            self.assertEqual(len(project.groups), 2)

這確實模擬了 os.listdir 成功.但我無法欺騙 Python 將 mocked_listdir.return_value 視為由文件和目錄組成.

This does mock os.listdir successfully. But I can't trick Python to treat mocked_listdir.return_value as consisting of files and directories.

我如何模擬 os.listdir 或 os.path.isdir，在同一個測試中，這樣測試就會看到alpha 和 beta 作為目錄，project.conf 作為文件?

How do I mock either os.listdir or os.path.isdir, in the same test, such that the test will see alpha and beta as directories and project.conf as a file?

推薦答案

我設法通過將一個可迭代對象傳遞給模擬的 isdir 的 side_effect 屬性來實現所需的行為對象.

I managed to achieve the desired behavior by passing an iterable to the side_effect attribute of the mocked isdir object.

import unittest
from unittest import mock
import Project

class TestRepo(unittest.TestCase):

  def test_load_project(self):
      project = Project("X")

      with mock.patch('os.listdir') as mocked_listdir:
        with mock.patch('os.path.isdir') as mocked_isdir:
          mocked_listdir.return_value = ['alpha', 'beta', 'project.conf']
          mocked_isdir.side_effect = [True, True, False]
          project.load()
          self.assertEqual(len(project.groups), 2)

關鍵是 mocked_isdir.side_effect = [True, True, False] 行.可迭代對象中的布爾值應與傳遞給 mocked_listdir.return_value 屬性的目錄和文件條目的順序相匹配.

The key is the mocked_isdir.side_effect = [True, True, False] line. The boolean values in the iterable should match the order of directory and file entries passed to the mocked_listdir.return_value attribute.

這篇關于如何在 Python 中模擬 os.listdir 來假裝文件和目錄?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！