问题
I have a django class based view that I'm decorating. Unfortunately that decorator makes outside calls to do status checks which is outside the scope of what the unit test should do so I want to override the decorator to do nothing during my unit tests. Here is my decorator:
decorators.py
def status_check(func):
@wraps(func)
def wrapped(request, *args, **kwargs):
uri = settings.SERVER_URI
status_code = None
bad_status = [404, 500]
try:
response = requests.head(uri)
except requests.ConnectionError as err:
LOGGER.error('Server is hosed! Oh Noes! Error: %s ' % (err))
raise Http404
except Exception as err:
LOGGER.error('Some crazy stuff is happening. Its Bad. '
'Error: %s' % (err))
raise Http404
status_code = response.status_code
if not status_code or status_code in bad_status:
LOGGER.error('Awww Snap! Server is not happy: %s' % (status_code))
raise Http404
return func(request, *args, **kwargs)
return wrapped
views.py
class HandleFoo(DetailView):
@method_decorator(status_check)
def post(self, request):
# do stuff here
tests.py
class RunTest(TestCase):
def test_post(self):
post_data = json.dumps({'stuff': 'vodka', 'things': 'tonic'})
resp = self.client.post(self.foo_uri,
post_data,
content_type='application/json',
)
self.assertEqual(resp.status_code, 200)
So is there a way for me to either override the decorator or can I bypass it altogether? I'm rather stumped on this.
EDIT Tried mocking out the request using the following from krak3n:
@patch('app.views.method_decorator.status_check', lambda func: func)
@patch('app.views.status_check', lambda func: func)
@patch('app.decorators.status_check', lambda func: func)
@patch('app.views.HandleFoo.post', lambda func: func)
The last method gets me the closest thus far, but it ends up throwing a stacktrace:
Traceback (most recent call last):
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/mock.py", line 1201, in patched
return func(*args, **keywargs)
File "/Users/squiddly/projects/tests/app/tests.py", line 165, in test_post
content_type='application/json',
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/test/client.py", line 463, in post
response = super(Client, self).post(path, data=data, content_type=content_type, **extra)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/test/client.py", line 297, in post
return self.request(**r)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/test/client.py", line 406, in request
response = self.handler(environ)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/test/client.py", line 111, in __call__
response = self.get_response(request)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/core/handlers/base.py", line 178, in get_response
response = self.handle_uncaught_exception(request, resolver, sys.exc_info())
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/core/handlers/base.py", line 224, in handle_uncaught_exception
return callback(request, **param_dict)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/utils/decorators.py", line 91, in _wrapped_view
response = view_func(request, *args, **kwargs)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/views/defaults.py", line 41, in server_error
return http.HttpResponseServerError(template.render(Context({})))
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/base.py", line 140, in render
return self._render(context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/test/utils.py", line 65, in instrumented_test_render
return self.nodelist.render(context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/base.py", line 830, in render
bit = self.render_node(node, context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/debug.py", line 74, in render_node
return node.render(context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/loader_tags.py", line 124, in render
return compiled_parent._render(context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/test/utils.py", line 65, in instrumented_test_render
return self.nodelist.render(context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/base.py", line 830, in render
bit = self.render_node(node, context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/debug.py", line 74, in render_node
return node.render(context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/loader_tags.py", line 156, in render
return self.render_template(self.template, context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/loader_tags.py", line 138, in render_template
output = template.render(context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/base.py", line 140, in render
return self._render(context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/test/utils.py", line 65, in instrumented_test_render
return self.nodelist.render(context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/base.py", line 830, in render
bit = self.render_node(node, context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/debug.py", line 74, in render_node
return node.render(context)
File "/Users/squiddly/envs/testenv/lib/python2.7/site-packages/django/template/base.py", line 1185, in render
_dict = func(*resolved_args, **resolved_kwargs)
File "/Users/squiddly/projects/tests/app/templatetags/app_extras.py", line 40, in get_data
if request.session.has_key('start_time'):
AttributeError: 'str' object has no attribute 'session'
回答1:
I think your gonna have to get into the dark underworld of Mock, but once you get your head around it (if you haven't already) the dark underworld turns into a bright blue heavenly sky of mockiness.
You could use the patch module of Mock to to patch this decorator so your views using it can become more testable: http://www.voidspace.org.uk/python/mock/patch.html. Personally I have not tried mocking a decorator before but it should work...
@patch('python.path.to.decorator', new_callable=PropertyMock)
def my_test(self, decorator_mock):
# your test code
Give that a whirl.
You can read about the patch module in Mock here: http://www.voidspace.org.uk/python/mock/patch.html
edit
new_callable=PropertyMock is probably not the right thing to do for patching a decorator.
Perhaps try:
@patch('python.path.to.decorator', lambda: func: func)
def my_test(self):
# your test code
This should in theory patch the decorator so it just returns the function back rather than does all the stuff you have in wrapped.
来源：https://stackoverflow.com/questions/15698425/overriding-decorator-during-unit-test-in-python