Support extension of JSON mimetype (#167)

* Support extension of JSON mimetype

* Py2.7 compat

msrest/pipeline/universal.py

@@ -32,6 +32,7 @@
 import xml.etree.ElementTree as ET
 import platform
 import codecs
+import re
 
 from typing import Mapping, Any, Optional, AnyStr, Union, IO, cast, TYPE_CHECKING  # pylint: disable=unused-import
 
@@ -129,10 +130,9 @@ def on_response(self, request, response, **kwargs):
 
 class RawDeserializer(SansIOHTTPPolicy):
 
-    JSON_MIMETYPES = [
-        'application/json',
-        'text/json' # Because we're open minded people...
-    ]
+    # Accept "text" because we're open minded people...
+    JSON_REGEXP = re.compile(r'^(application|text)/([a-z+.]+\+)?json$')
+
     # Name used in context
     CONTEXT_NAME = "deserialized_data"
 
@@ -165,7 +165,7 @@ def deserialize_from_text(cls, data, content_type=None):
         if content_type is None:
             return data
 
-        if content_type in cls.JSON_MIMETYPES:
+        if cls.JSON_REGEXP.match(content_type):
             try:
                 return json.loads(data_as_str)
             except ValueError as err:

tests/test_universal_pipeline.py

@@ -151,6 +151,12 @@ def body(self):
     result = response.context["deserialized_data"]
     assert result["success"] is True
 
+    # Simple JSON with complex content_type
+    response = build_response(b'{"success": true}', content_type="application/vnd.microsoft.appconfig.kv+json")
+    raw_deserializer.on_response(None, response, stream=False)
+    result = response.context["deserialized_data"]
+    assert result["success"] is True
+
     # JSON with UTF-8 BOM
     response = build_response(b'\xef\xbb\xbf{"success": true}', content_type="application/json; charset=utf-8")
     raw_deserializer.on_response(None, response, stream=False)