Ability to filter repository collaborators (#938)

## Changes
- Add `affiliation` parameter to `get_collaborators()` and use it to filter collaborators through the API
- Resolves #937


PS: Would have loved to add a simple test for this but there seems to be a problem on my end using OAuth as I'm just not able to authenticate to the API during tests.

github/Repository.py

@@ -60,6 +60,7 @@
 # Copyright 2018 per1234 <accounts@perglass.com>                               #
 # Copyright 2018 sechastain <sechastain@gmail.com>                             #
 # Copyright 2018 sfdye <tsfdye@gmail.com>                                      #
+# Copyright 2018 Vinay Hegde <vinayhegde2010@gmail.com>
 #                                                                              #
 # This file is part of PyGithub.                                               #
 # http://pygithub.readthedocs.io/                                              #
@@ -1340,16 +1341,26 @@ class Repository(github.GithubObject.CompletableGithubObject):
             None
         )
 
-    def get_collaborators(self):
+    def get_collaborators(self, affiliation=github.GithubObject.NotSet):
         """
         :calls: `GET /repos/:owner/:repo/collaborators <http://developer.github.com/v3/repos/collaborators>`_
+        :param affiliation: string
         :rtype: :class:`github.PaginatedList.PaginatedList` of :class:`github.NamedUser.NamedUser`
         """
+
+        url_parameters = dict()
+        allowed_affiliations = ['outside', 'direct', 'all']
+        if affiliation is not github.GithubObject.NotSet:
+            assert isinstance(affiliation, str), affiliation
+            assert affiliation in allowed_affiliations, \
+                'Affiliation can be one of ' + ', '.join(allowed_affiliations)
+            url_parameters['affiliation'] = affiliation
+
         return github.PaginatedList.PaginatedList(
             github.NamedUser.NamedUser,
             self._requester,
             self.url + "/collaborators",
-            None
+            url_parameters
         )
 
     def get_comment(self, id):

github/tests/AllTests.py

@@ -20,6 +20,7 @@
 # Copyright 2018 Steve Kowalik <steven@wedontsleep.org>                        #
 # Copyright 2018 Wan Liuyang <tsfdye@gmail.com>                                #
 # Copyright 2018 sfdye <tsfdye@gmail.com>                                      #
+# Copyright 2018 Vinay Hegde <vinayhegde2010@gmail.com>
 #                                                                              #
 # This file is part of PyGithub.                                               #
 # http://pygithub.readthedocs.io/                                              #
@@ -120,3 +121,4 @@ from Issue216 import *
 from Issue278 import *
 from Issue494 import *
 from Issue572 import *
+from Issue937 import *

github/tests/Issue937.py

@@ -0,0 +1,38 @@
+# -*- coding: utf-8 -*-
+
+############################ Copyrights and license ############################
+#                                                                              #
+# Copyright 2018 Vinay Hegde <vinayhegde2010@gmail.com>                        #
+#                                                                              #
+# This file is part of PyGithub.                                               #
+# http://pygithub.readthedocs.io/                                              #
+#                                                                              #
+# PyGithub is free software: you can redistribute it and/or modify it under    #
+# the terms of the GNU Lesser General Public License as published by the Free  #
+# Software Foundation, either version 3 of the License, or (at your option)    #
+# any later version.                                                           #
+#                                                                              #
+# PyGithub is distributed in the hope that it will be useful, but WITHOUT ANY  #
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS    #
+# FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more #
+# details.                                                                     #
+#                                                                              #
+# You should have received a copy of the GNU Lesser General Public License     #
+# along with PyGithub. If not, see <http://www.gnu.org/licenses/>.             #
+#                                                                              #
+################################################################################
+import Framework
+
+import github
+
+class Issue937(Framework.TestCase):
+    def setUp(self):
+        Framework.TestCase.setUp(self)
+        self.user = self.g.get_user()
+        self.repo = self.user.get_repo("PyGithub")
+
+    def testCollaboratorsAffiliation(self):
+        collaborators = self.repo.get_collaborators(affiliation='direct')
+        self.assertListKeyEqual(collaborators, lambda u: u.login, ["hegde5"])
+        with self.assertRaises(AssertionError):
+            self.repo.get_collaborators(affiliation='invalid_option')

github/tests/ReplayData/Issue937.testCollaboratorsAffiliation.txt

@@ -0,0 +1,11 @@
+https
+GET
+api.github.com
+None
+/repos/hegde5/PyGithub/collaborators?affiliation=direct
+{'Authorization': 'Basic login_and_password_removed', 'User-Agent': 'PyGithub/Python'}
+None
+200
+[('Server', 'GitHub.com'), ('Date', 'Sun, 21 Oct 2018 21:13:36 GMT'), ('Content-Type', 'application/json; charset=utf-8'), ('Transfer-Encoding', 'chunked'), ('Status', '200 OK'), ('X-RateLimit-Limit', '5000'), ('X-RateLimit-Remaining', '4995'), ('X-RateLimit-Reset', '1540157093'), ('Cache-Control', 'private, max-age=60, s-maxage=60'), ('Vary', 'Accept, Authorization, Cookie, X-GitHub-OTP'), ('ETag', 'W/"db23c025efd980c5fc4249cde2e34de0"'), ('X-OAuth-Scopes', 'admin:gpg_key, admin:org, admin:org_hook, admin:public_key, admin:repo_hook, gist, notifications, repo, user, write:discussion'), ('X-Accepted-OAuth-Scopes', ''), ('X-GitHub-Media-Type', 'github.v3; format=json'), ('Access-Control-Expose-Headers', 'ETag, Link, Retry-After, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval'), ('Access-Control-Allow-Origin', '*'), ('Strict-Transport-Security', 'max-age=31536000; includeSubdomains; preload'), ('X-Frame-Options', 'deny'), ('X-Content-Type-Options', 'nosniff'), ('X-XSS-Protection', '1; mode=block'), ('Referrer-Policy', 'origin-when-cross-origin, strict-origin-when-cross-origin'), ('Content-Security-Policy', "default-src 'none'"), ('Content-Encoding', 'gzip'), ('X-GitHub-Request-Id', 'E700:4832:2D5EDDC:66CB0FA:5BCCEC00')]
+[{"login":"hegde5","id":8609211,"node_id":"MDQ6VXNlcjg2MDkyMTE=","avatar_url":"https://avatars2.githubusercontent.com/u/8609211?v=4","gravatar_id":"","url":"https://api.github.com/users/hegde5","html_url":"https://github.com/hegde5","followers_url":"https://api.github.com/users/hegde5/followers","following_url":"https://api.github.com/users/hegde5/following{/other_user}","gists_url":"https://api.github.com/users/hegde5/gists{/gist_id}","starred_url":"https://api.github.com/users/hegde5/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/hegde5/subscriptions","organizations_url":"https://api.github.com/users/hegde5/orgs","repos_url":"https://api.github.com/users/hegde5/repos","events_url":"https://api.github.com/users/hegde5/events{/privacy}","received_events_url":"https://api.github.com/users/hegde5/received_events","type":"User","site_admin":false,"permissions":{"admin":true,"push":true,"pull":true}}]
+