Export headers in GithubException (#1887)

Since the headers that led to an exception are also useful, firstly pass
them into the constructor, and then export them in a property. Test one
specific use case to make sure of coverage.

Fixes #1814

github/GithubException.py

@@ -38,11 +38,12 @@ class GithubException(Exception):
     Some other types of exceptions might be raised by underlying libraries, for example for network-related issues.
     """
 
-    def __init__(self, status, data):
+    def __init__(self, status, data, headers):
         super().__init__()
         self.__status = status
         self.__data = data
-        self.args = [status, data]
+        self.__headers = headers
+        self.args = [status, data, headers]
 
     @property
     def status(self):
@@ -58,6 +59,13 @@ class GithubException(Exception):
         """
         return self.__data
 
+    @property
+    def headers(self):
+        """
+        The headers returned by the Github API
+        """
+        return self.__headers
+
     def __str__(self):
         return "{status} {data}".format(status=self.status, data=json.dumps(self.data))
 

github/GithubException.pyi

@@ -1,13 +1,16 @@
 from typing import Any, Dict, List, Optional, Tuple, Type, Union
 
 class GithubException(Exception):
-    def __init__(self, status: Union[int, str], data: Any,) -> None: ...
+    def __init__(self, status: Union[int, str], data: Any, headers: Optional[Dict[str, str]]) -> None: ...
     def __str__(self) -> str: ...
     @property
     def data(self) -> Dict[str, Union[str, List[str], List[Dict[str, str]]]]: ...
     @property
     def status(self) -> int: ...
 
+    @property
+    def headers(self) -> Union[None, Dict[str, str]]: ...
+
 class BadAttributeException(GithubException):
     def __init__(
         self,

github/GithubObject.py

@@ -300,7 +300,7 @@ class CompletableGithubObject(GithubObject):
     def __complete(self):
         if self._url.value is None:
             raise GithubException.IncompletableObject(
-                400, "Returned object contains no URL"
+                400, "Returned object contains no URL", None
             )
         headers, data = self._requester.requestJsonAndCheck("GET", self._url.value)
         self._storeAndUseAttributes(headers, data)

github/Requester.py

@@ -435,7 +435,7 @@ class Requester:
             cls = GithubException.UnknownObjectException
         else:
             cls = GithubException.GithubException
-        return cls(status, output)
+        return cls(status, output, headers)
 
     def __structuredFromJson(self, data):
         if len(data) == 0:

tests/Exceptions.py

@@ -90,7 +90,7 @@ class Exceptions(Framework.TestCase):
         self.assertEqual(str(raisedexp.exception), '401 {"message": "Bad credentials"}')
 
     def testExceptionPickling(self):
-        pickle.loads(pickle.dumps(github.GithubException("foo", "bar")))
+        pickle.loads(pickle.dumps(github.GithubException("foo", "bar", None)))
 
 
 class SpecificExceptions(Framework.TestCase):
@@ -134,7 +134,9 @@ class SpecificExceptions(Framework.TestCase):
                 res = self.g.search_code("jacquev6")
                 res.get_page(0)
 
-        self.assertRaises(github.RateLimitExceededException, exceed)
+        with self.assertRaises(github.RateLimitExceededException) as raised:
+            exceed()
+        self.assertEqual(raised.exception.headers.get("retry-after"), "60")
 
     def testIncompletableObject(self):
         github.UserKey.UserKey.setCheckAfterInitFlag(False)