Raise exception if json is not the expected type

There are a few corner cases we need to handle where json isn't the
typical type we expect. In those (rare) cases, we need to raise a better
exception for the user's benefit.

Closes #310

github3/exceptions.py

@@ -3,7 +3,6 @@
 
 
 class GitHubError(Exception):
-
     """The base exception class."""
 
     def __init__(self, resp):
@@ -35,76 +34,70 @@ def message(self):
         return self.msg
 
 
-class BadRequest(GitHubError):
+class UnprocessableResponseBody(GitHubError):
+    """Exception class for response objects that cannot be handled."""
+    def __init__(self, message, body):
+        Exception.__init__(self, message)
+        self.body = body
+
+    def __str__(self):
+        return self.message
 
-    """Exception class for 400 responses."""
 
+class BadRequest(GitHubError):
+    """Exception class for 400 responses."""
     pass
 
 
 class AuthenticationFailed(GitHubError):
-
     """Exception class for 401 responses.
 
     Possible reasons:
 
     - Need one time password (for two-factor authentication)
     - You are not authorized to access the resource
     """
-
     pass
 
 
 class ForbiddenError(GitHubError):
-
     """Exception class for 403 responses.
 
     Possible reasons:
 
     - Too many requests (you've exceeded the ratelimit)
     - Too many login failures
     """
-
     pass
 
 
 class NotFoundError(GitHubError):
-
     """Exception class for 404 responses."""
-
     pass
 
 
 class MethodNotAllowed(GitHubError):
-
     """Exception class for 405 responses."""
-
     pass
 
 
 class NotAcceptable(GitHubError):
-
     """Exception class for 406 responses."""
-
     pass
 
 
 class UnprocessableEntity(GitHubError):
-
     """Exception class for 422 responses."""
-
     pass
 
 
 class ClientError(GitHubError):
-
     """Catch-all for 400 responses that aren't specific errors."""
+    pass
 
 
 class ServerError(GitHubError):
-
     """Exception class for 5xx responses."""
-
     pass
 
 

github3/models.py

@@ -13,8 +13,8 @@
 from datetime import datetime
 from logging import getLogger
 
+from . import exceptions
 from .decorators import requires_auth
-from .exceptions import error_for
 from .null import NullObject
 from .session import GitHubSession
 from .utils import UTC
@@ -143,6 +143,10 @@ def _remove_none(data):
     def _instance_or_null(self, instance_class, json):
         if json is None:
             return NullObject(instance_class.__name__)
+        if not isinstance(json, dict):
+            return exceptions.UnprocessableResponseBody(
+                "GitHub's API returned a body that could not be handled", json
+            )
         try:
             return instance_class(json, self)
         except TypeError:  # instance_class is not a subclass of GitHubCore
@@ -171,7 +175,7 @@ def _boolean(self, response, true_code, false_code):
             if status_code == true_code:
                 return True
             if status_code != false_code and status_code >= 400:
-                raise error_for(response)
+                raise exceptions.error_for(response)
         return False
 
     def _delete(self, url, **kwargs):

github3/structs.py

@@ -1,14 +1,18 @@
 # -*- coding: utf-8 -*-
-from collections import Iterator
-from .models import GitHubCore
+import collections
+import functools
+
 from requests.compat import urlparse, urlencode
 
+from . import exceptions
+from . import models
+
 
-class GitHubIterator(GitHubCore, Iterator):
+class GitHubIterator(models.GitHubCore, collections.Iterator):
     """The :class:`GitHubIterator` class powers all of the iter_* methods."""
     def __init__(self, count, url, cls, session, params=None, etag=None,
                  headers=None):
-        GitHubCore.__init__(self, {}, session)
+        models.GitHubCore.__init__(self, {}, session)
         #: Original number of items requested
         self.original = count
         #: Number of items left in the iterator
@@ -45,7 +49,7 @@ def _repr(self):
         return '<GitHubIterator [{0}, {1}]>'.format(self.count, self.path)
 
     def __iter__(self):
-        self.last_url, params, cls = self.url, self.params, self.cls
+        self.last_url, params = self.url, self.params
         headers = self.headers
 
         if 0 < self.count <= 100 and self.count != -1:
@@ -54,6 +58,10 @@ def __iter__(self):
         if 'per_page' not in params and self.count == -1:
             params['per_page'] = 100
 
+        cls = self.cls
+        if issubclass(self.cls, models.GitHubCore):
+            cls = functools.partial(self.cls, session=self)
+
         while (self.count == -1 or self.count > 0) and self.last_url:
             response = self._get(self.last_url, params=params,
                                  headers=headers)
@@ -72,14 +80,19 @@ def __iter__(self):
 
             # languages returns a single dict. We want the items.
             if isinstance(json, dict):
+                if issubclass(self.cls, models.GitHubObject):
+                    raise exceptions.UnprocessableResponseBody(
+                        "GitHub's API returned a body that could not be"
+                        " handled", json
+                    )
                 if json.get('ETag'):
                     del json['ETag']
                 if json.get('Last-Modified'):
                     del json['Last-Modified']
                 json = json.items()
 
             for i in json:
-                yield cls(i, self) if issubclass(cls, GitHubCore) else cls(i)
+                yield cls(i)
                 self.count -= 1 if self.count > 0 else 0
                 if self.count == 0:
                     break

tests/cassettes/Repository_invalid_refs.json

@@ -0,0 +1 @@
+{"recorded_with": "betamax/0.4.1", "http_interactions": [{"recorded_at": "2015-02-22T04:23:56", "request": {"headers": {"Content-Type": "application/json", "Accept-Charset": "utf-8", "Accept-Encoding": "gzip, deflate", "Connection": "keep-alive", "User-Agent": "github3.py/1.0.0a1", "Accept": "application/vnd.github.v3.full+json"}, "body": {"encoding": "utf-8", "string": ""}, "method": "GET", "uri": "https://api.github.com/repos/sigmavirus24/github3.py"}, "response": {"headers": {"Access-Control-Allow-Origin": "*", "X-Content-Type-Options": "nosniff", "Access-Control-Allow-Credentials": "true", "Content-Type": "application/json; charset=utf-8", "Transfer-Encoding": "chunked", "Date": "Sun, 22 Feb 2015 04:23:56 GMT", "Access-Control-Expose-Headers": "ETag, Link, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval", "Content-Security-Policy": "default-src 'none'", "X-GitHub-Media-Type": "github.v3; param=full; format=json", "Status": "200 OK", "ETag": "W/\"07acb8446729c2cedb1aa44279995ef3\"", "Cache-Control": "public, max-age=60, s-maxage=60", "X-XSS-Protection": "1; mode=block", "X-Frame-Options": "deny", "Strict-Transport-Security": "max-age=31536000; includeSubdomains; preload", "X-RateLimit-Reset": "1424580854", "Content-Encoding": "gzip", "Server": "GitHub.com", "X-RateLimit-Limit": "60", "X-GitHub-Request-Id": "451DE374:0FF4:16646F2B:54E959DC", "X-RateLimit-Remaining": "43", "Vary": "Accept, Accept-Encoding", "X-Served-By": "474556b853193c38f1b14328ce2d1b7d", "Last-Modified": "Sun, 22 Feb 2015 02:56:55 GMT"}, "body": {"base64_string": "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", "encoding": "utf-8", "string": ""}, "status": {"message": "OK", "code": 200}, "url": "https://api.github.com/repos/sigmavirus24/github3.py"}}, {"recorded_at": "2015-02-22T04:23:56", "request": {"headers": {"Content-Type": "application/json", "Accept-Charset": "utf-8", "Accept-Encoding": "gzip, deflate", "Connection": "keep-alive", "User-Agent": "github3.py/1.0.0a1", "Accept": "application/vnd.github.v3.full+json"}, "body": {"encoding": "utf-8", "string": ""}, "method": "GET", "uri": "https://api.github.com/repos/sigmavirus24/github3.py/git/refs/heads/develop?per_page=100"}, "response": {"headers": {"Access-Control-Allow-Origin": "*", "Content-Security-Policy": "default-src 'none'", "X-Content-Type-Options": "nosniff", "Access-Control-Allow-Credentials": "true", "Content-Type": "application/json; charset=utf-8", "Transfer-Encoding": "chunked", "Date": "Sun, 22 Feb 2015 04:23:56 GMT", "Access-Control-Expose-Headers": "ETag, Link, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval", "X-Frame-Options": "deny", "X-GitHub-Media-Type": "github.v3; param=full; format=json", "Status": "200 OK", "ETag": "W/\"f148066c5c6c3ba6ca6116fed0a94fb0\"", "Cache-Control": "public, max-age=60, s-maxage=60", "X-XSS-Protection": "1; mode=block", "X-Poll-Interval": "300", "Strict-Transport-Security": "max-age=31536000; includeSubdomains; preload", "X-RateLimit-Reset": "1424580854", "Content-Encoding": "gzip", "Server": "GitHub.com", "X-RateLimit-Limit": "60", "X-GitHub-Request-Id": "451DE374:0FF4:16646F65:54E959DC", "X-RateLimit-Remaining": "42", "Vary": "Accept, Accept-Encoding", "X-Served-By": "d594a23ec74671eba905bf91ef329026", "Last-Modified": "Sun, 22 Feb 2015 02:56:55 GMT"}, "body": {"base64_string": "H4sIAAAAAAAAA6WOyw6DIBBF/4V146BgffwNyFRoNBAGTIzx34tx20WTbiaT3DtnzsEivth4TQKLyhAY3HDxgT1YjkuJbEqBRgAVXDW7ZLOuJr9CxOAJyM2r2lzM1Ei4U1GF/VpL4wvT6zdOiY0HI6sKHeVQ90J3WjWGSyOQy7ZW7TRgU3MueK+wH9pnV3TSHrBclOerS//r3RyCnw3O8wNTw7SJLgEAAA==", "encoding": "utf-8", "string": ""}, "status": {"message": "OK", "code": 200}, "url": "https://api.github.com/repos/sigmavirus24/github3.py/git/refs/heads/develop?per_page=100"}}]}

tests/integration/test_repos_repo.py

@@ -1,10 +1,13 @@
 """Integration tests for Repositories."""
 import github3
+import github3.exceptions as exc
 
-from .helper import IntegrationHelper
+import pytest
 
+from . import helper
 
-class TestRepository(IntegrationHelper):
+
+class TestRepository(helper.IntegrationHelper):
 
     """Integration tests for the Repository object."""
 
@@ -411,6 +414,15 @@ def test_refs(self):
         for ref in references:
             assert isinstance(ref, github3.git.Reference)
 
+    def test_refs_raises_unprocessable_exception(self):
+        """Verify github3.exceptions.UnprocessableResponseBody is raised."""
+        cassette_name = self.cassette_name('invalid_refs')
+        with self.recorder.use_cassette(cassette_name):
+            repository = self.gh.repository('sigmavirus24', 'github3.py')
+            assert repository is not None
+            with pytest.raises(exc.UnprocessableResponseBody):
+                list(repository.refs('heads/develop'))
+
     def test_stargazers(self):
         """Test the ability to retrieve the stargazers on a repository."""
         cassette_name = self.cassette_name('stargazers')

tests/unit/test_structs.py

@@ -5,10 +5,9 @@
 class TestGitHubIterator(UnitHelper):
     described_class = GitHubIterator
 
-    def setUp(self):
-        super(TestGitHubIterator, self).setUp()
-        self.count = -1
-        self.cls = object
+    def after_setup(self):
+        self.count = self.instance.count = -1
+        self.cls = self.instance.cls = object
 
     def create_instance_of_described_class(self):
         self.url = 'https://api.github.com/users'