Special case? ValueError: "No JSON object could be decoded" for JSON response with an empty body

[kiminoa]

======================================================================
ERROR: test_request (gabbi.driver.test_env_loader_env_notes_delete_environment_note)
gabbi.driver.test_env_loader_env_notes_delete_environment_note.test_request
----------------------------------------------------------------------
_StringException: Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/gabbi/case.py", line 78, in wrapper
    func(self)
  File "/Library/Python/2.7/site-packages/gabbi/case.py", line 118, in test_request
    self._run_test()
  File "/Library/Python/2.7/site-packages/gabbi/case.py", line 312, in _run_test
    self._run_request(full_url, method, headers, body)
  File "/Library/Python/2.7/site-packages/gabbi/case.py", line 279, in _run_request
    self.json_data = json.loads(decoded_output)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/__init__.py", line 338, in loads
    return _default_decoder.decode(s)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py", line 365, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py", line 383, in raw_decode
    raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded

defaults:
    request_headers:
        accept: application/json
        content-type: application/json
    response_headers:
        content-type: application/json

tests:
    - name: delete environment note
      verbose: True
      method: DELETE
      # Use previous $RESPONSE to get note ID
      url: /v2/notes/$RESPONSE['$.id']
      status: 302 || 200

Response body: empty
Response headers:

Status Code: 200
X-Runtime: 0.302572
Date: Wed, 10 Jun 2015 17:37:25 GMT
Content-Encoding: gzip
X-Rack-Cache: invalidate, pass
Server: nginx
ETag: W/"7215ee9c7d9dc229d2921a40e899ec5f"
Vary: Accept-Encoding
Content-Type: application/json; charset=utf-8
Status: 200 OK
Cache-Control: max-age=0, private, must-revalidate
Transfer-Encoding: chunked
Connection: keep-alive
X-Request-Id: 1d3efa9239c321a00155be9e1d44324f
X-UA-Compatible: IE=Edge,chrome=1

[kiminoa]

PEBKAC.

My workaround was to nix the default headers' content-type and individually specify them for each test. This specific test wanted a javascript response, but test-specific headers didn't override the default. I'll file a separate issue for that for consideration.

I don't know if there's a use case where an empty JSON body could happen where this is still a bug, but in our case, the DELETE issues a javascript response my default.

[cdent]

Note that this error can only happen if there was something other than an empty string in the body of your response because of this line which basically says "only decode the body if there is a body and the content type says 'json'".

So it seems there's something weird going on with the body of your response?