Add description for permissions

Fixes: https://pagure.io/koji/issue/335

tests/test_hub/test_edit_permission.py

@@ -0,0 +1,44 @@
+import unittest
+
+import mock
+
+import koji
+import kojihub
+
+
+UP = kojihub.UpdateProcessor
+
+
+class TestEditPermission(unittest.TestCase):
+
+    def setUp(self):
+        self.lookup_perm = mock.patch('kojihub.lookup_perm').start()
+        self.update_processor = mock.patch('kojihub.UpdateProcessor').start()
+        self.exports = kojihub.RootExports()
+        self.context = mock.patch('kojihub.context').start()
+        # It seems MagicMock will not automatically handle attributes that
+        # start with "assert"
+        self.context.session.assertPerm = mock.MagicMock()
+        self.context.session.assertLogin = mock.MagicMock()
+        self.perm_name = 'test_perms'
+        self.perm_info = {'id': 1, 'name': self.perm_name}
+        self.description = 'test-description'
+
+    def test_edit_permission_non_exist_permission(self):
+        self.lookup_perm.side_effect = koji.GenericError
+        with self.assertRaises(koji.GenericError):
+            self.exports.editPermission(self.perm_name, self.description)
+        self.update_processor.assert_not_called()
+        self.context.session.assertPerm.assert_called_with('admin')
+
+    def test_edit_permission(self):
+        self.lookup_perm.return_value = self.perm_info
+        update = self.update_processor.return_value
+        self.exports.editPermission(self.perm_name, self.description)
+        self.update_processor.assert_called_once()
+        update.execute.assert_called_once()
+        args, kwargs = self.update_processor.call_args
+        up = UP(*args, **kwargs)
+        self.assertEqual(up.table, 'permissions')
+        self.assertEqual(up.rawdata, {})
+        self.context.session.assertPerm.assert_called_with('admin')