FIX error handling when adding comments to Jira (#59)

In some cases Jira returned error messages in "errorMessages" and field
"errors" is empty which caused IndexError...

tests/test_jira.py

@@ -1,7 +1,7 @@
 import logging
 from collections import namedtuple
 from unittest import main, TestCase
-from unittest.mock import patch
+from unittest.mock import patch, Mock
 
 import requests
 from ticketutil.ticket import TicketException
@@ -506,6 +506,58 @@ def test_prepare_ticket_fields_components(self):
         prepared_fields = jira._prepare_ticket_fields(fields)
         self.assertEqual(prepared_fields, expected_fields)
 
+    @patch.object(jira.JiraTicket, '_create_requests_session')
+    def test_comment_errors(self, mock_session_factoy):
+        """
+        Test if error responses are handled correctly when adding comments.
+        """
+        mock_response = Mock()
+        mock_response.raise_for_status.side_effect = requests.RequestException()
+        mock_response.status_code = 400
+        mock_response.json.return_value = {
+            "errorMessages": [],
+            "errors": {
+                "comment": "Comment body can not be empty!"
+            }
+        }
+
+        mock_session = Mock()
+        mock_session.post = Mock(return_value=mock_response)
+
+        mock_session_factoy.return_value = mock_session
+
+        ticket = jira.JiraTicket(URL, PROJECT, ticket_id=TICKET_ID)
+
+        # This should not raise `IndexError: list index out of range` when
+        # handling error
+        ticket.add_comment('foobar')
+
+    @patch.object(jira.JiraTicket, '_create_requests_session')
+    def test_comment_error_messages(self, mock_session_factoy):
+        """
+        Test if error responses are handled correctly when adding comments.
+        """
+        mock_response = Mock()
+        mock_response.raise_for_status.side_effect = requests.RequestException()
+        mock_response.status_code = 400
+        mock_response.json.return_value = {
+            "errorMessages": [
+                "You do not have the permission to comment on this issue."
+            ],
+            "errors": {}
+        }
+
+        mock_session = Mock()
+        mock_session.post.return_value = mock_response
+
+        mock_session_factoy.return_value = mock_session
+
+        ticket = jira.JiraTicket(URL, PROJECT, ticket_id=TICKET_ID)
+
+        # This should not raise `IndexError: list index out of range` when
+        # handling error
+        ticket.add_comment('foobar')
+
 
 if __name__ == '__main__':
     main()

ticketutil/jira.py

@@ -185,7 +185,7 @@ def _create_ticket_request(self, params):
             logger.debug("Create ticket: status code: {0}".format(r.status_code))
             r.raise_for_status()
         except requests.RequestException as e:
-            error_message = "Error creating ticket - {0}".format(list(r.json()['errors'].values())[0])
+            error_message = "Error creating ticket - {0}".format(_extract_error_messages(r.json()))
             logger.error(error_message)
             logger.error(e)
             return self.request_result._replace(status='Failure', error_message=error_message)
@@ -236,7 +236,7 @@ def edit(self, **kwargs):
             self.request_result = self.get_ticket_content()
             return self.request_result
         except requests.RequestException as e:
-            error_message = "Error editing ticket - {0}".format(list(r.json()['errors'].values())[0])
+            error_message = "Error editing ticket - {0}".format(_extract_error_messages(r.json()))
             logger.error(error_message)
             logger.error(e)
             return self.request_result._replace(status='Failure', error_message=error_message)
@@ -264,7 +264,7 @@ def add_comment(self, comment):
             self.request_result = self.get_ticket_content()
             return self.request_result
         except requests.RequestException as e:
-            error_message = "Error adding comment to ticket - {0}".format(list(r.json()['errors'].values())[0])
+            error_message = "Error adding comment to ticket - {0}".format(_extract_error_messages(r.json()))
             logger.error(error_message)
             logger.error(e)
             return self.request_result._replace(status='Failure', error_message=error_message)
@@ -512,6 +512,14 @@ def _prepare_ticket_fields(fields):
         return fields
 
 
+def _extract_error_messages(data):
+    if data.get('errorMessages'):
+        return ' '.join(data['errorMessages'])
+    elif data.get('errors'):
+        return ' '.join(data['errors'].values())
+    return ''
+
+
 def main():
     """
     main() function, not directly callable.