fix(aci): correctly query open periods within date range

src/sentry/models/groupopenperiod.py

@@ -144,21 +144,41 @@ def get_open_periods_for_group(
     query_end: datetime | None = None,
     limit: int | None = None,
 ) -> BaseQuerySet[GroupOpenPeriod]:
+    """
+    Get open periods for a group that overlap with the query time range.
+
+    To overlap with [query_start, query_end], an open period must:
+    1. Start before the query ends
+    2. End after the query starts (or still be open)
+
+    This covers all overlap cases:
+    - Period starts before query and ends within query range
+    - Period starts before query and ends after query (open period spans entire query range)
+    - Period starts within query and ends within query (open period completely inside query range)
+    - Period starts within query and ends after query
+    - Period starts before query and is still open
+    - Period starts within query and is still open
+    """
     if not should_create_open_periods(group.type):
         return GroupOpenPeriod.objects.none()
 
     if not query_start:
         # use whichever date is more recent to reduce the query range. first_seen could be > 90 days ago
         query_start = max(group.first_seen, timezone.now() - timedelta(days=90))
+    if not query_end:
+        query_end = timezone.now()
+
+    started_before_query_ends = Q(date_started__lte=query_end)
+    ended_after_query_starts = Q(date_ended__gte=query_start)
+    still_open = Q(date_ended__isnull=True)
 
-    group_open_periods = GroupOpenPeriod.objects.filter(
-        group=group,
-        date_started__gte=query_start,
-    ).order_by("-date_started")
-    if query_end:
-        group_open_periods = group_open_periods.filter(
-            Q(date_ended__lte=query_end) | Q(date_ended__isnull=True)
+    group_open_periods = (
+        GroupOpenPeriod.objects.filter(
+            group=group,
         )
+        .filter(started_before_query_ends & (ended_after_query_starts | still_open))
+        .order_by("-date_started")
+    )
 
     return group_open_periods[:limit]
 

tests/sentry/workflow_engine/endpoints/test_organization_open_periods.py

@@ -1,3 +1,5 @@
+from datetime import timedelta
+
 from django.utils import timezone
 
 from sentry.incidents.grouptype import MetricIssue
@@ -280,3 +282,127 @@ def test_open_periods_limit(self) -> None:
         assert resp["start"] == unresolved_time
         assert resp["end"] == second_resolved_time
         assert resp["isOpen"] is False
+
+    def test_get_open_periods_time_range_starts_after_query_start(self) -> None:
+        """Test that open periods starting after query_start and ending after query_end are included."""
+        base_time = timezone.now() - timedelta(days=10)
+        GroupOpenPeriod.objects.filter(group=self.group).delete()
+
+        # Open period: Day 2 to Day 7
+        open_period = GroupOpenPeriod.objects.create(
+            group=self.group,
+            project=self.group.project,
+            date_started=base_time + timedelta(days=2),
+            date_ended=base_time + timedelta(days=7),
+        )
+
+        # Query range: Day 0 to Day 5
+        query_start = base_time.isoformat()
+        query_end = (base_time + timedelta(days=5)).isoformat()
+
+        response = self.get_success_response(
+            *self.get_url_args(),
+            qs_params={
+                "groupId": self.group.id,
+                "start": query_start,
+                "end": query_end,
+            },
+        )
+
+        assert len(response.data) == 1
+        resp = response.data[0]
+        assert resp["id"] == str(open_period.id)
+
+    def test_get_open_periods_time_range_starts_before_ends_within(self) -> None:
+        """Test that open periods starting before query_start and ending before query_end are included."""
+
+        base_time = timezone.now() - timedelta(days=10)
+
+        GroupOpenPeriod.objects.filter(group=self.group).delete()
+
+        # Open period: Day 0 to Day 3 (ends within range)
+        open_period = GroupOpenPeriod.objects.create(
+            group=self.group,
+            project=self.group.project,
+            date_started=base_time,
+            date_ended=base_time + timedelta(days=3),
+        )
+
+        # Query range: Day 2 to Day 7
+        query_start = (base_time + timedelta(days=2)).isoformat()
+        query_end = (base_time + timedelta(days=7)).isoformat()
+
+        response = self.get_success_response(
+            *self.get_url_args(),
+            qs_params={
+                "groupId": self.group.id,
+                "start": query_start,
+                "end": query_end,
+            },
+        )
+
+        assert len(response.data) == 1
+        resp = response.data[0]
+        assert resp["id"] == str(open_period.id)
+
+    def test_get_open_periods_time_range_starts_before_still_ongoing(self) -> None:
+        """Test that open periods starting before query_start and still ongoing (date_ended=None) are included."""
+
+        base_time = timezone.now() - timedelta(days=10)
+
+        GroupOpenPeriod.objects.filter(group=self.group).delete()
+
+        # Open period: Day 1 to ongoing
+        open_period = GroupOpenPeriod.objects.create(
+            group=self.group,
+            project=self.group.project,
+            date_started=base_time + timedelta(days=1),
+            date_ended=None,
+        )
+
+        # Query range: Day 0 to Day 7
+        query_start = base_time.isoformat()
+        query_end = (base_time + timedelta(days=7)).isoformat()
+
+        response = self.get_success_response(
+            *self.get_url_args(),
+            qs_params={
+                "groupId": self.group.id,
+                "start": query_start,
+                "end": query_end,
+            },
+        )
+
+        assert len(response.data) == 1
+        resp = response.data[0]
+        assert resp["id"] == str(open_period.id)
+
+    def test_get_open_periods_none_in_range(self) -> None:
+        """Test that open periods outside the query range are not included."""
+
+        base_time = timezone.now() - timedelta(days=10)
+
+        GroupOpenPeriod.objects.filter(group=self.group).delete()
+
+        # Open period: Day 0 to Day 1 (starts + ends before query range)
+        GroupOpenPeriod.objects.create(
+            group=self.group,
+            project=self.group.project,
+            date_started=base_time,
+            date_ended=base_time + timedelta(days=1),
+        )
+
+        # Query range: Day 2 to Day 7
+        query_start = (base_time + timedelta(days=2)).isoformat()
+        query_end = (base_time + timedelta(days=7)).isoformat()
+
+        response = self.get_success_response(
+            *self.get_url_args(),
+            qs_params={
+                "groupId": self.group.id,
+                "start": query_start,
+                "end": query_end,
+            },
+        )
+
+        assert len(response.data) == 0