AttributeError: 'NoneType' object has no attribute 'decode' when 'body' in match_on, fixed with 'raw_body'

[jhh3000]

When using vcr with the following configuration with 'body', there are errors with loading the JSON response -- it could be due to a blank response or blank payload. When I use 'raw_body' it works perfectly. Here's the stack trace (relevant sections):

  File "/home/vagrant/venv/local/lib/python2.7/site-packages/requests/sessions.py", line 473, in get
    return self.request('GET', url, **kwargs)
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/requests/sessions.py", line 461, in request
    resp = self.send(prep, **send_kwargs)
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/requests/sessions.py", line 573, in send
    r = adapter.send(request, **kwargs)
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/requests/adapters.py", line 370, in send
    timeout=timeout
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/requests/packages/urllib3/connectionpool.py", line 518, in urlopen
    body=body, headers=headers)
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/requests/packages/urllib3/connectionpool.py", line 353, in _make_request
    httplib_response = conn.getresponse(buffering=True)
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/vcr/stubs/__init__.py", line 219, in getresponse
    if self.cassette.can_play_response_for(self._vcr_request):
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/vcr/cassette.py", line 232, in can_play_response_for
    return request and request in self and \
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/vcr/cassette.py", line 303, in __contains__
    for index, response in self._responses(request):
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/vcr/cassette.py", line 227, in _responses
    if requests_match(request, stored_request, self._match_on):
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/vcr/matchers.py", line 97, in requests_match
    matches = [(m(r1, r2), m) for m in matchers]
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/vcr/matchers.py", line 80, in body
    return transformer(read_body(r1)) == transformer(read_body(r2))
  File "/home/vagrant/venv/local/lib/python2.7/site-packages/vcr/matchers.py", line 52, in _transform_json
    return json.loads(body.decode('utf-8'))
AttributeError: 'NoneType' object has no attribute 'decode'

[maroux]

@jhh3000 I ran into the same problem - it looks like your cassette may be problematic. For me, I had a request like this:

- request:
    body: null
    headers:
      Content-Length: ['41']
      Content-Type: [application/json]
    method: GET

The Content-Type being json is the problem here. Removing that header seems to fix the cassette. This was caused by me editing the cassette by hand. Hope this helps.

[simon-weber]

This is a bug, right? Even though it may be atypical, null is valid json. Either the cassette should be persisting 'null' instead of null, or matchers._transform_json should be able to handle None.

Probably we want to do both? That way, cassettes will be backwards compatible.