Publically joinable Groups (#697)

* Add public field to AuthGroup

* Add permission for users to join non-public groups

By default this permission will be applied to the "Member" group to
maintain the current behaviour.

* Allow users to join public groups

Users without the 'groupmanagement.request_groups' permission will be
able to join groups marked as public but will not be able to see or join
any other groups.

* Prevent None state change from purging groups

Currently when a user drops from Blue or Member state all groups and
permissions are discarded. This softens that approach by not removing
public groups and creates a distinction between the two activities. An
argument could maybe be made for not removing permissions on a state
change, but that is beyond the scope of this change.

* Correct syntax for removing filtered groups

* Add unit tests for disable user and member

* Update services signals tests

* Correct mocking call

* Remove permissions checking from menu item

authentication/tests/test_tasks.py

@@ -0,0 +1,84 @@
+from __future__ import unicode_literals
+
+try:
+    # Py3
+    from unittest import mock
+except ImportError:
+    # Py2
+    import mock
+
+from django.test import TestCase
+from django.contrib.auth.models import Group, Permission
+
+from alliance_auth.tests.auth_utils import AuthUtils
+
+from authentication.tasks import disable_member, disable_user
+
+
+class AuthenticationTasksTestCase(TestCase):
+    def setUp(self):
+        self.member = AuthUtils.create_member('auth_member')
+        self.none_user = AuthUtils.create_user('none_user', disconnect_signals=True)
+
+    @mock.patch('services.signals.transaction')
+    def test_disable_member(self, transaction):
+        # Inert signals action
+        transaction.on_commit.side_effect = lambda fn: fn()
+
+        # Add permission
+        perm = Permission.objects.create(codename='test_perm', name='test perm', content_type_id=1)
+
+        # Add public group
+        pub_group = Group.objects.create(name="A Public group")
+        pub_group.authgroup.internal = False
+        pub_group.authgroup.public = True
+        pub_group.save()
+
+        # Setup member
+        self.member.user_permissions.add(perm)
+        self.member.groups.add(pub_group)
+
+        # Pre assertion
+        self.assertIn(pub_group, self.member.groups.all())
+        self.assertGreater(len(self.member.groups.all()), 1)
+
+        # Act
+        disable_member(self.member)
+
+        # Assert
+        self.assertIn(pub_group, self.member.groups.all())
+        # Everything but the single public group wiped
+        self.assertEqual(len(self.member.groups.all()), 1)
+        # All permissions wiped
+        self.assertEqual(len(self.member.user_permissions.all()), 0)
+
+    @mock.patch('services.signals.transaction')
+    def test_disable_user(self, transaction):
+        # Inert signals action
+        transaction.on_commit.side_effect = lambda fn: fn()
+
+        # Add permission
+        perm = Permission.objects.create(codename='test_perm', name='test perm', content_type_id=1)
+
+        # Add public group
+        pub_group = Group.objects.create(name="A Public group")
+        pub_group.authgroup.internal = False
+        pub_group.authgroup.public = True
+        pub_group.save()
+
+        # Setup member
+        self.member.user_permissions.add(perm)
+        self.member.groups.add(pub_group)
+
+        # Pre assertion
+        self.assertIn(pub_group, self.member.groups.all())
+        self.assertGreater(len(self.member.groups.all()), 1)
+
+        # Act
+        disable_user(self.member)
+
+        # Assert
+        # All groups wiped
+        self.assertEqual(len(self.member.groups.all()), 0)
+        # All permissions wiped
+        self.assertEqual(len(self.member.user_permissions.all()), 0)