fix: Update time in draft to account for edge cases and update tests

issue_metrics.py

@@ -125,8 +125,7 @@ def get_per_issue_metrics(
                 ready_for_review_at = get_time_to_ready_for_review(issue, pull_request)
                 if env_vars.draft_pr_tracking:
                     issue_with_metrics.time_in_draft = measure_time_in_draft(
-                        issue=issue,
-                        ready_for_review_at=ready_for_review_at,
+                        issue=issue
                     )
 
             if env_vars.hide_time_to_first_response is False:

test_time_in_draft.py

@@ -18,38 +18,79 @@ def setUp(self):
         Setup common test data and mocks.
         """
         self.issue = MagicMock()
-        self.issue.issue.created_at = datetime(2021, 1, 1, tzinfo=pytz.utc)
         self.issue.issue.state = "open"
 
     def test_time_in_draft_with_ready_for_review(self):
         """
-        Test measure_time_in_draft when ready_for_review_at is provided.
+        Test measure_time_in_draft with one draft and review interval.
         """
-        ready_for_review_at = datetime(2021, 1, 3, tzinfo=pytz.utc)
-        result = measure_time_in_draft(self.issue, ready_for_review_at)
+        self.issue.events.return_value = [
+            MagicMock(event="converted_to_draft", created_at=datetime(2021, 1, 1, tzinfo=pytz.utc)),
+            MagicMock(event="ready_for_review", created_at=datetime(2021, 1, 3, tzinfo=pytz.utc)),
+        ]
+        result = measure_time_in_draft(self.issue)
         expected = timedelta(days=2)
         self.assertEqual(result, expected, "The time in draft should be 2 days.")
 
     def test_time_in_draft_without_ready_for_review(self):
         """
         Test measure_time_in_draft when ready_for_review_at is not provided and issue is still open.
         """
+        self.issue.events.return_value = [
+            MagicMock(event="converted_to_draft", created_at=datetime(2021, 1, 1, tzinfo=pytz.utc)),
+        ]
         now = datetime(2021, 1, 4, tzinfo=pytz.utc)
         with unittest.mock.patch("time_in_draft.datetime") as mock_datetime:
             mock_datetime.now.return_value = now
-            result = measure_time_in_draft(self.issue, None)
+            result = measure_time_in_draft(self.issue)
             expected = timedelta(days=3)
             self.assertEqual(result, expected, "The time in draft should be 3 days.")
 
+    def test_time_in_draft_multiple_intervals(self):
+        """
+        Test measure_time_in_draft with multiple draft intervals.
+        """
+        self.issue.events.return_value = [
+            MagicMock(event="converted_to_draft", created_at=datetime(2021, 1, 1, tzinfo=pytz.utc)),
+            MagicMock(event="ready_for_review", created_at=datetime(2021, 1, 3, tzinfo=pytz.utc)),
+            MagicMock(event="converted_to_draft", created_at=datetime(2021, 1, 5, tzinfo=pytz.utc)),
+            MagicMock(event="ready_for_review", created_at=datetime(2021, 1, 7, tzinfo=pytz.utc)),
+        ]
+        result = measure_time_in_draft(self.issue)
+        expected = timedelta(days=4)
+        self.assertEqual(result, expected, "The total time in draft should be 4 days.")
+
+    def test_time_in_draft_ongoing_draft(self):
+        """
+        Test measure_time_in_draft with an ongoing draft interval.
+        """
+        self.issue.events.return_value = [
+            MagicMock(event="converted_to_draft", created_at=datetime(2021, 1, 1, tzinfo=pytz.utc)),
+        ]
+        with unittest.mock.patch("time_in_draft.datetime") as mock_datetime:
+            mock_datetime.now.return_value = datetime(2021, 1, 4, tzinfo=pytz.utc)
+            result = measure_time_in_draft(self.issue)
+            expected = timedelta(days=3)
+            self.assertEqual(result, expected, "The ongoing draft time should be 3 days.")
+
+    def test_time_in_draft_no_draft_events(self):
+        """
+        Test measure_time_in_draft with no draft-related events.
+        """
+        self.issue.events.return_value = []
+        result = measure_time_in_draft(self.issue)
+        self.assertIsNone(result, "The result should be None when there are no draft events.")
+
     def test_time_in_draft_without_ready_for_review_and_closed(self):
         """
-        Test measure_time_in_draft when ready_for_review_at is not provided and issue is closed.
+        Test measure_time_in_draft for a closed issue with an ongoing draft and ready_for_review_at is not provided.
         """
+        self.issue.events.return_value = [
+            MagicMock(event="converted_to_draft", created_at=datetime(2021, 1, 1, tzinfo=pytz.utc)),
+        ]
         self.issue.issue.state = "closed"
-        result = measure_time_in_draft(self.issue, None)
-        self.assertIsNone(
-            result, "The result should be None when draft was never used."
-        )
+        result = measure_time_in_draft(self.issue)
+        self.assertIsNone(result, "The result should be None for a closed issue with an ongoing draft.")
 
 
 class TestGetStatsTimeInDraft(unittest.TestCase):

time_in_draft.py

@@ -13,23 +13,32 @@
 
 def measure_time_in_draft(
     issue: github3.issues.Issue,
-    ready_for_review_at: Union[datetime, None],
-) -> Union[datetime, None]:
-    """If a pull request has had time in the draft state, return the amount of time it was in draft.
+) -> Union[timedelta, None]:
+    """If a pull request has had time in the draft state, return the cumulative amount of time it was in draft.
 
     args:
         issue (github3.issues.Issue): A GitHub issue which has been pre-qualified as a pull request.
-        ready_for_review_at (datetime | None): The time the pull request was marked as
-            ready for review.
 
     returns:
-        Union[datetime, None]: The time the pull request was in draft state.
+        Union[timedelta, None]: Total time the pull request has spent in draft state.
     """
-    if ready_for_review_at:
-        return ready_for_review_at - issue.issue.created_at
-    if issue.issue.state == "open":
-        return datetime.now(pytz.utc) - issue.issue.created_at
-    return None
+    events = issue.events()
+    draft_start = None
+    total_draft_time = timedelta(0)
+
+    for event in events:
+        if event.event == "converted_to_draft":
+            draft_start = event.created_at
+        elif event.event == "ready_for_review" and draft_start:
+            # Calculate draft time for this interval
+            total_draft_time += event.created_at - draft_start
+            draft_start = None
+
+    # If the PR is currently in draft state, calculate the time in draft up to now
+    if draft_start and issue.issue.state == "open":
+        total_draft_time += datetime.now(pytz.utc) - draft_start
+
+    return total_draft_time if total_draft_time > timedelta(0) else None
 
 
 def get_stats_time_in_draft(