Fix out of range error from totalCount

Signed-off-by: Luiz Carvalho <lucarval@redhat.com>

Author: lcarva

reviewrot/githubstack.py

@@ -193,11 +193,19 @@ def get_last_comment(self, pr):
         last_issue_comment = None
         last_comment = None
 
-        if review_comments.totalCount > 0:
+        try:
+            # review_comments.totalCount may return a non-zero value when
+            # the list of comments is actually empty :(
             last_review_comment = review_comments.reversed[0]
+        except IndexError:
+            pass
 
-        if issue_comments.totalCount > 0:
+        try:
+            # issue_comments.totalCount may return a non-zero value when
+            # the list of comments is actually empty :(
             last_issue_comment = issue_comments.reversed[0]
+        except IndexError:
+            pass
 
         # check which is newer if pr has both types of comments
         if last_issue_comment and last_review_comment:

test/github_tests/mock_github.py

@@ -49,8 +49,10 @@ class MockGithubCommentsOlder:
 class MockGithubCommentsEmpty:
     """Mocks Github Comment object with no comments."""
 
-    totalCount = 0
-    reversed = [MockValue]
+    # Simulate the bug from the PyGithub package, where
+    # totalCount is non-zero when there are no comments.
+    totalCount = int(2)
+    reversed = []
 
 
 class MockPull:

test/github_tests/test_github.py

@@ -75,8 +75,7 @@ def test_get_last_comment_nothing(self, mock_lastcomment):
         # Call function
         response = GithubService().get_last_comment(mock_pr)
 
-        # Validate function calls and response
-        mock_lastcomment.assert_not_called()
+        # Validate function response
         self.assertIsNone(response)
 
     @patch(PATH + "GithubService.check_request_state")