fix(issues): Start writing new_group_first_seen in merge case (#97682)

This is part of an effort to fix the issue-search's sort-by-age feature.
As part of that feature, we are adding the "first_seen" time of a group
to each error. When we merge groups, we want to update the errors to
have the new group's "group_first_seen".

We've decided to do that by explicitly passing the primary group's
"first_seen" time along with the Kafka message. This PR starts writing
that field properly; it must wait until
[snuba#7351](getsentry/snuba#7351) has fully
deployed.

Author: thetruecpaul

src/sentry/eventstream/base.py

@@ -147,7 +147,11 @@ def end_delete_groups(self, state: Mapping[str, Any]) -> None:
         pass
 
     def start_merge(
-        self, project_id: int, previous_group_ids: Sequence[int], new_group_id: int
+        self,
+        project_id: int,
+        previous_group_ids: Sequence[int],
+        new_group_id: int,
+        new_group_first_seen: datetime | None = None,
     ) -> dict[str, Any]:
         raise NotImplementedError
 

src/sentry/eventstream/snuba.py

@@ -54,6 +54,7 @@
 #       'project_id': id,
 #       'previous_group_ids': [id2, id2],
 #       'new_group_id': id,
+#       'group_first_seen': timestamp,
 #       'datetime': timestamp,
 #   })
 #   Unmerge: (2, '(start_unmerge|end_unmerge)', {
@@ -229,7 +230,11 @@ def end_delete_groups(self, state: Mapping[str, Any]) -> None:
         )
 
     def start_merge(
-        self, project_id: int, previous_group_ids: Sequence[int], new_group_id: int
+        self,
+        project_id: int,
+        previous_group_ids: Sequence[int],
+        new_group_id: int,
+        new_group_first_seen: datetime | None = None,
     ) -> dict[str, Any]:
         if not previous_group_ids:
             raise ValueError("expected groups to merge!")
@@ -242,13 +247,16 @@ def start_merge(
             "datetime": json.datetime_to_str(datetime.now(tz=timezone.utc)),
         }
 
+        if new_group_first_seen is not None:
+            state["new_group_first_seen"] = json.datetime_to_str(new_group_first_seen)
+
         self._send(project_id, "start_merge", extra_data=(state,), asynchronous=False)
 
         return state
 
     def end_merge(self, state: Mapping[str, Any]) -> None:
         state_copy: MutableMapping[str, Any] = {**state}
-        state_copy["datetime"] = datetime.now(tz=timezone.utc)
+        state_copy["datetime"] = json.datetime_to_str(datetime.now(tz=timezone.utc))
         self._send(
             state_copy["project_id"], "end_merge", extra_data=(state_copy,), asynchronous=False
         )

src/sentry/issues/merge.py

@@ -56,7 +56,7 @@ def handle_merge(
 
     group_ids_to_merge = [g.id for g in groups_to_merge]
     eventstream_state = eventstream.backend.start_merge(
-        primary_group.project_id, group_ids_to_merge, primary_group.id
+        primary_group.project_id, group_ids_to_merge, primary_group.id, primary_group.first_seen
     )
 
     Group.objects.filter(id__in=group_ids_to_merge).update(

tests/sentry/issues/endpoints/test_organization_group_index.py

@@ -4034,7 +4034,10 @@ def test_merge(
         )
 
         mock_eventstream.start_merge.assert_called_once_with(
-            group1.project_id, [group3.id, group1.id], group2.id
+            group1.project_id,
+            [group3.id, group1.id],
+            group2.id,
+            group2.first_seen,
         )
 
         assert len(merge_groups.mock_calls) == 1

tests/sentry/issues/test_merge.py

@@ -1,5 +1,4 @@
-from typing import Any
-from unittest.mock import patch
+from unittest.mock import MagicMock, patch
 
 import pytest
 import rest_framework
@@ -13,6 +12,7 @@
 from sentry.testutils.skips import requires_snuba
 from sentry.types.activity import ActivityType
 from sentry.types.group import GroupSubStatus
+from sentry.utils import json
 
 pytestmark = [requires_snuba]
 
@@ -29,7 +29,7 @@ def setUp(self) -> None:
             self.groups.append(group)
 
     @patch("sentry.tasks.merge.merge_groups.delay")
-    def test_handle_merge(self, merge_groups: Any) -> None:
+    def test_handle_merge(self, merge_groups: MagicMock) -> None:
         Activity.objects.all().delete()
         merge = handle_merge(self.groups, self.project_lookup, self.user)
 
@@ -39,6 +39,10 @@ def test_handle_merge(self, merge_groups: Any) -> None:
         assert len(groups.filter(substatus__isnull=True)) == 4
         assert merge_groups.called
 
+        assert merge_groups.call_args[1]["eventstream_state"][
+            "new_group_first_seen"
+        ] == json.datetime_to_str(min([g.first_seen for g in groups]))
+
         primary_group = self.groups[0]
         assert Activity.objects.filter(type=ActivityType.MERGE.value, group=primary_group)
         assert merge["parent"] == str(primary_group.id)

tests/snuba/api/endpoints/test_project_group_index.py

@@ -1342,7 +1342,10 @@ def test_merge(
         )
 
         mock_eventstream.start_merge.assert_called_once_with(
-            group1.project_id, [group3.id, group1.id], group2.id
+            group1.project_id,
+            [group3.id, group1.id],
+            group2.id,
+            group2.first_seen,
         )
 
         assert len(merge_groups.mock_calls) == 1