Raise ContentTypeError by json() when headers does not … (#2136)

* Raise ClientResponseContentTypeError by json() when headers does not meet the spec.

* Docs changed to reflect the exception raised by json()

* Added #2136 as a new feature change

* Renamed long ClientResonseContentTypeError to ContentTypeError

* Update client_exceptions.py

aiohttp/client_exceptions.py

@@ -13,6 +13,8 @@
     'ServerFingerprintMismatch',
 
     'ClientResponseError', 'ClientPayloadError',
+    'ContentTypeError',
+
     'ClientHttpProxyError', 'WSServerHandshakeError')
 
 
@@ -37,6 +39,10 @@ def __init__(self, request_info, history, *,
         super().__init__("%s, message='%s'" % (code, message))
 
 
+class ContentTypeError(ClientResponseError):
+    """ContentType found is not valid."""
+
+
 class WSServerHandshakeError(ClientResponseError):
     """websocket server handshake error."""
 

aiohttp/client_reqrep.py

@@ -13,7 +13,7 @@
 
 from . import hdrs, helpers, http, payload
 from .client_exceptions import (ClientConnectionError, ClientOSError,
-                                ClientResponseError)
+                                ClientResponseError, ContentTypeError)
 from .formdata import FormData
 from .helpers import PY_35, HeadersMixin, SimpleCookie, TimerNoop, noop
 from .http import SERVER_SOFTWARE, HttpVersion10, HttpVersion11, PayloadWriter
@@ -722,7 +722,7 @@ def json(self, *, encoding=None, loads=json.loads,
         if content_type:
             ctype = self.headers.get(hdrs.CONTENT_TYPE, '').lower()
             if content_type not in ctype:
-                raise ClientResponseError(
+                raise ContentTypeError(
                     self.request_info,
                     self.history,
                     message=('Attempt to decode JSON with '

changes/2136.feature

@@ -0,0 +1,2 @@
+json() raises a ContentTypeError exception if the content-type
+does not meet the requirements instead of raising a generic ClientResponseError.

docs/client_reference.rst

@@ -1050,6 +1050,9 @@ Response object
       Close underlying connection if data reading gets an error,
       release connection otherwise.
 
+      Raise an :exc:`aiohttp.ClientResponseError` if the data can't
+      be read.
+
       :return bytes: read *BODY*.
 
       .. seealso:: :meth:`close`, :meth:`release`.
@@ -1104,15 +1107,16 @@ Response object
                       content_type='application/json')
 
       Read response's body as *JSON*, return :class:`dict` using
-      specified *encoding* and *loader*.
+      specified *encoding* and *loader*. If data is not still available
+      a ``read`` call will be done, 
 
       If *encoding* is ``None`` content encoding is autocalculated
       using :term:`cchardet` or :term:`chardet` as fallback if
       *cchardet* is not available.
 
       if response's `content-type` does not match `content_type` parameter
-      :exc:`aiohttp.ClientResponseError` get raised. To disable content type
-      check pass ``None`` value.
+      :exc:`aiohttp.ContentTypeError` get raised.
+      To disable content type check pass ``None`` value.
 
       :param str encoding: text encoding used for *BODY* decoding, or
                            ``None`` for encoding autodetection

tests/test_client_response.py

@@ -352,18 +352,27 @@ def custom(content):
 
 
 @asyncio.coroutine
-def test_json_no_content(loop, session):
+def test_json_invalid_content_type(loop, session):
     response = ClientResponse('get', URL('http://def-cl-resp.org'))
     response._post_init(loop, session)
     response.headers = {
         'Content-Type': 'data/octet-stream'}
     response._content = b''
 
-    with pytest.raises(aiohttp.ClientResponseError) as info:
+    with pytest.raises(aiohttp.ContentTypeError) as info:
         yield from response.json()
 
     assert info.value.request_info == response.request_info
 
+
+@asyncio.coroutine
+def test_json_no_content(loop, session):
+    response = ClientResponse('get', URL('http://def-cl-resp.org'))
+    response._post_init(loop, session)
+    response.headers = {
+        'Content-Type': 'data/octet-stream'}
+    response._content = b''
+
     res = yield from response.json(content_type=None)
     assert res is None