✨ feat(notifications): open_period_start_for_group util for threads

src/sentry/notifications/utils/open_period.py

@@ -0,0 +1,27 @@
+from datetime import datetime
+
+from sentry.models.activity import Activity, ActivityType
+from sentry.models.group import Group
+
+
+def open_period_start_for_group(group: Group) -> datetime | None:
+    """
+    Get the start of the open period for a group.
+    This is the last activity of the group that is not a resolution or the first_seen of the group.
+    We need to check the first seen since we don't create an activity when the group is created.
+    """
+
+    # Get the last activity of the group
+    latest_unresolved_activity: Activity | None = (
+        Activity.objects.filter(
+            group=group,
+            type=ActivityType.SET_UNRESOLVED.value,
+        )
+        .order_by("-datetime")
+        .first()
+    )
+
+    if latest_unresolved_activity:
+        return latest_unresolved_activity.datetime
+
+    return group.first_seen

tests/sentry/notifications/utils/test_open_period.py

@@ -0,0 +1,69 @@
+from django.utils import timezone
+
+from sentry.models.activity import Activity
+from sentry.models.group import GroupStatus
+from sentry.notifications.utils.open_period import open_period_start_for_group
+from sentry.testutils.cases import TestCase
+from sentry.types.activity import ActivityType
+
+
+class OpenPeriodTestCase(TestCase):
+    def setUp(self):
+        self.group = self.create_group()
+
+    def test_new_group_returns_first_seen(self) -> None:
+        """Test that a new group returns first_seen as the open period start"""
+        start = open_period_start_for_group(self.group)
+        assert start == self.group.first_seen
+
+    def test_unresolved_group_returns_unresolved_activity(self) -> None:
+        """Test that a group with unresolved activity returns that activity time"""
+        # First resolve the group
+        self.group.status = GroupStatus.RESOLVED
+        self.group.save()
+        resolved_time = timezone.now()
+        Activity.objects.create(
+            group=self.group,
+            project=self.group.project,
+            type=ActivityType.SET_RESOLVED.value,
+            datetime=resolved_time,
+        )
+
+        # Then unresolve it
+        unresolved_time = timezone.now()
+        self.group.status = GroupStatus.UNRESOLVED
+        self.group.save()
+        unresolved_activity = Activity.objects.create(
+            group=self.group,
+            project=self.group.project,
+            type=ActivityType.SET_UNRESOLVED.value,
+            datetime=unresolved_time,
+        )
+
+        start = open_period_start_for_group(self.group)
+        assert start is not None
+        assert start == unresolved_activity.datetime
+
+    def test_multiple_unresolved_returns_latest(self) -> None:
+        """Test that with multiple unresolved activities, we get the latest one"""
+        # Create first unresolved activity
+        first_unresolved = timezone.now()
+        Activity.objects.create(
+            group=self.group,
+            project=self.group.project,
+            type=ActivityType.SET_UNRESOLVED.value,
+            datetime=first_unresolved,
+        )
+
+        # Create second unresolved activity
+        second_unresolved = timezone.now()
+        second_activity = Activity.objects.create(
+            group=self.group,
+            project=self.group.project,
+            type=ActivityType.SET_UNRESOLVED.value,
+            datetime=second_unresolved,
+        )
+
+        start = open_period_start_for_group(self.group)
+        assert start is not None
+        assert start == second_activity.datetime