Add exception to indicate an incomplete data set

sigmavirus24 · omgjlk · commit 2460c6b8e257 · 2017-12-14T21:32:21.000-08:00
This communicates far more clearly to the user what may have happened to cause issues with the response they were expecting. In the case of the issue raised, this points people towards the token they may be using and its scopes. Closes sigmavirus24#693
diff --git a/github3/exceptions.py b/github3/exceptions.py
@@ -34,6 +34,22 @@ def message(self):
         return self.msg
 
 
+class IncompleteResponse(GitHubError):
+    """Exception for a response that doesn't have everything it should."""
+
+    def __init__(self, json, exception):
+        self.response = None
+        self.code = None
+        self.json = json
+        self.errors = []
+        self.exception = exception
+        self.msg = (
+            "The library was expecting more data in the response (%r)."
+            " Either GitHub modified it's response body, or your token"
+            " is not properly scoped to retrieve this information."
+        ) % (exception,)
+
+
 class ResponseError(GitHubError):
     """The base exception for errors stemming from GitHub responses."""
     pass
diff --git a/github3/models.py b/github3/models.py
@@ -48,7 +48,10 @@ def __init__(self, json, session=None):
             self.last_modified = json.pop('Last-Modified', None)
             self._uniq = json.get('url', None)
         self._json_data = json
-        self._update_attributes(json)
+        try:
+            self._update_attributes(json)
+        except KeyError as kerr:
+            raise exceptions.IncompleteResponse(json, kerr)
 
     def _update_attributes(self, json):
         pass
