Eve broken with werzeug >= 0.15.3

[sunbit]

I actually realized of this when tests failed from a PR i was preparing, and then tests on travis also failed. After some debugging i tracked down the error to werkzeug, and to this particular change referenced in this issue

pallets/werkzeug#1516
pallets/werkzeug@4ee2464

If i understant correctly, they are fixing something that was not right, but it breaks the expected value format of exceptions www_authenticate parameter here:

https://github.com/pyeve/eve/blob/master/eve/endpoints.py#L173:L174

were eve was expecting a (None,) when now it's simply None.

I'm not sure if this should be considered something wrong on werkzeug's side for changing that behavoir and file a bug there, or fix such assumption in eve.

What do you think?

---

Expected Behavior

Test pass in any environment

Actual Behavior

Auth tests fail when using werkzeug >=0.15.3

======================================================== test session starts ========================================================
platform darwin -- Python 2.7.16, pytest-4.5.0, py-1.8.0, pluggy-0.11.0
cachedir: .tox/py27/.pytest_cache
rootdir: /private/tmp/eve, inifile: pytest.ini
collected 796 items                                                                                                                 

eve/tests/auth.py .....F....F

============================================================= FAILURES ==============================================================
____________________________________________ TestBasicAuth.test_authorized_media_access _____________________________________________

self = <eve.tests.auth.TestBasicAuth testMethod=test_authorized_media_access>

    def test_authorized_media_access(self):
        self.app.config["RETURN_MEDIA_AS_BASE64_STRING"] = False
        self.app.config["RETURN_MEDIA_AS_URL"] = True
        self.app.config["BANDWIDTH_SAVER"] = False
        self.app._init_media_endpoint()
    
        clean = b"my new file contents"
        test_field, test_value = "ref", "9234567890123456789054321"
        data = {"media": (BytesIO(clean), "test.txt"), test_field: test_value}
        r, s = self.parse_response(
            self.test_client.post(
                self.known_resource_url, data=data, headers=self.valid_media_auth
            )
        )
        self.assert201(s)
    
        file_url = r["media"]
        r = self.test_client.get(file_url, headers=self.invalid_auth)
>       self.assert401(r.status_code)

eve/tests/auth.py:155: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
eve/tests/__init__.py:339: in assert401
    self.assertEqual(status, 401)
E   AssertionError: 500 != 401
--------------------------------------------------------- Captured log call ---------------------------------------------------------
ERROR    flask.app:app.py:1761 Exception on /media/5cdc2983d9d4670e2cbf4687 [GET]
Traceback (most recent call last):
  File "/private/tmp/eve/.tox/py27/lib/python2.7/site-packages/flask/app.py", line 2292, in wsgi_app
    response = self.full_dispatch_request()
  File "/private/tmp/eve/.tox/py27/lib/python2.7/site-packages/flask/app.py", line 1815, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/private/tmp/eve/.tox/py27/lib/python2.7/site-packages/flask/app.py", line 1713, in handle_user_exception
    return self.handle_http_exception(e)
  File "/private/tmp/eve/.tox/py27/lib/python2.7/site-packages/flask/app.py", line 1644, in handle_http_exception
    return handler(e)
  File "/private/tmp/eve/eve/endpoints.py", line 182, in error_endpoint
    return send_response(None, (response, None, None, error.code, headers))
  File "/private/tmp/eve/eve/render.py", line 52, in decorated
    r = f(*args, **kwargs)
  File "/private/tmp/eve/eve/render.py", line 92, in send_response
    return _prepare_response(resource, *response if response else [None])
  File "/private/tmp/eve/eve/render.py", line 164, in _prepare_response
    for header, value in headers:
TypeError: 'NoneType' object is not iter

Environment

• Python version: any python version
• Eve version: master

[nicolaiarocci]

They sure have been playing around a lot with that Unauthorized thing. 0.15.1 broke it, and now 0.15.3 does it again 😄 I have pinned Werkzeug to 0.15.3 for the time being. We'll see if their API stabilizes over time.