使用 mock 模拟导入的模块以测试 Pylons 控制器功能

Question

我一直在寻找实现模拟以测试 Pylons 控制器功能的问题。

我要测试的特定功能可以在这里找到：https://hg.mozilla.org/build/buildapi/file/efe11511f42d/buildapi/controllers/selfserve.py#l210

目标：

我只是想模拟出它调用的函数，以便我可以确认它最终会调用 get_completeness。

问题：

我可以很好地模拟 _ok、_get_stable_delay、_failed 和 _branches_cache。但是当涉及到 g.buildapi_cache.get_builds_for_revision 时，我似乎无法正确地模拟它，并且每次调用 revision() 时都会失败。

g 实际上是 pylons.app_globals 并被导入 selfserve.py 控制器，如下所示：'from pylons import app_globals as g'

测试：

我正在使用 python 解释器来测试所有这些。这些是我正在尝试的 2 个实现：http://pastebin.mozilla.org/2931825 和 http://pastebin.mozilla.org/2931832

总而言之，这里是解释器中的完整运行，并带有 http://pastebin.mozilla.org/2931825 的 Traceback

>>> from buildapi.controllers.selfserve import SelfserveController
>>> from mock import patch, Mock
>>> s = SelfserveController()
>>> s._ok = Mock(name='_ok')
>>> s._get_stable_delay = Mock(return_value=180)
>>> s._branches_cache = Mock()
>>> s._branches_cache = {'try': None}
>>> s._failed = Mock(return_value="Failed")
>>> with patch('buildapi.controllers.selfserve.g.buildapi_cache.get_builds_for_revision') as get_builds_for_revision:
...         get_builds_for_revision.return_value = ['baz', 'bang']
...         result = revision('try', 'bar')
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/jzeller/buildapi-test/lib/python2.7/site-packages/mock.py", line 1252, in __enter__
    self.target = self.getter()
  File "/Users/jzeller/buildapi-test/lib/python2.7/site-packages/mock.py", line 1414, in <lambda>
    getter = lambda: _importer(target)
  File "/Users/jzeller/buildapi-test/lib/python2.7/site-packages/mock.py", line 1102, in _importer
    thing = _dot_lookup(thing, comp, import_path)
  File "/Users/jzeller/buildapi-test/lib/python2.7/site-packages/mock.py", line 1089, in _dot_lookup
    return getattr(thing, comp)
  File "/Users/jzeller/buildapi-test/lib/python2.7/site-packages/paste/registry.py", line 137, in __getattr__
    return getattr(self._current_obj(), attr)
  File "/Users/jzeller/buildapi-test/lib/python2.7/site-packages/paste/registry.py", line 197, in _current_obj
    'thread' % self.____name__)
TypeError: No object (name: app_globals) has been registered for this thread

这里是http://pastebin.mozilla.org/2931832

>>> from buildapi.controllers.selfserve import SelfserveController
>>> from mock import patch, Mock

>>> s = SelfserveController()
>>> s._ok = Mock(name='_ok')
>>> s._get_stable_delay = Mock(return_value=180)
>>> s._branches_cache = Mock()
>>> s._branches_cache = {'try': None}
>>> s._failed = Mock(return_value="Failed")
>>> g = Mock()
>>> g.buildapi_cache = Mock(name='buildapi_cache')
>>> g.buildapi_cache.get_builds_for_revision = Mock(name='get_builds_for_revision', return_value=['baz', 'bang'])
>>> s.revision('try', 'bar')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "buildapi/controllers/selfserve.py", line 217, in revision
    job_items = g.buildapi_cache.get_builds_for_revision(branch, revision)
  File "/Users/jzeller/buildapi-test/lib/python2.7/site-packages/paste/registry.py", line 137, in __getattr__
    return getattr(self._current_obj(), attr)
  File "/Users/jzeller/buildapi-test/lib/python2.7/site-packages/paste/registry.py", line 197, in _current_obj
    'thread' % self.____name__)
TypeError: No object (name: app_globals) has been registered for this thread

这与我尝试运行修订时遇到的错误相同。每次它在这里出错是因为我试图模拟这个 app_globals 模块失败了，或者看起来是这样。我真的不确定如何尝试这个。 有人有什么想法吗？

这里有一些更好的细节：

• 这是我正在尝试使用的函数，它在我正在实例化的类中：https://hg.mozilla.org/build/buildapi/file/efe11511f42d/buildapi/controllers/selfserve.py#l210

注 1

我已经查看了以下似乎不太适用于这个特定场景的线程，或者我完全没有抓住重点。

• Mocking imported modules in Python
• Mocking away the url object in Pylons

Answer 1

如果没有初始化 Pylons 的环境，控制器就不能用作独立对象。

使用 Pylons 提供的测试功能可以让您免于使用所有样板代码来测试控制器。

我建议您将 TestController 类与鼻子测试结合使用，如 documentation 所示。

特别是对于您的代码，我认为 Pylons 对待 private 方法（以 _ 开头）与 public 方法不同，因为公共方法在请求的上下文中运行。 p>