fix(trends): Fixed trends first time user matching event (#28325)

posthog/hogql_queries/insights/trends/aggregation_operations.py

@@ -118,7 +118,7 @@ def is_active_users_math(self):
         return self.series.math in ["weekly_active", "monthly_active"]
 
     def is_first_time_ever_math(self):
-        return self.series.math == "first_time_for_user"
+        return self.series.math in {"first_time_for_user", "first_matching_event_for_user"}
 
     def is_first_matching_event(self):
         return self.series.math == "first_matching_event_for_user"
@@ -465,7 +465,6 @@ def get_first_time_math_query_orchestrator(
         events_where_clause: ast.Expr,
         sample_value: ast.RatioExpr,
         event_name_filter: ast.Expr | None = None,
-        is_first_matching_event: bool = False,
     ):
         date_placeholders = self.query_date_range.to_placeholders()
         date_from = parse_expr(
@@ -479,6 +478,7 @@ def get_first_time_math_query_orchestrator(
 
         events_query = ast.SelectQuery(select=[])
         parent_select = self._first_time_parent_query(events_query)
+        is_first_matching_event = self.is_first_matching_event()
 
         class QueryOrchestrator:
             events_query_builder: FirstTimeForUserEventsQueryAlternator

posthog/hogql_queries/insights/trends/test/test_trends_query_runner.py

@@ -5022,6 +5022,13 @@ def test_trends_aggregation_first_matching_event_for_user(self):
             distinct_ids=["p1"],
             properties={},
         )
+        _create_event(
+            team=self.team,
+            event="$pageview",
+            distinct_id="p1",
+            timestamp="2020-01-06T12:00:00Z",
+            properties={"$browser": "Firefox"},
+        )
         _create_event(
             team=self.team,
             event="$pageview",
@@ -5069,3 +5076,116 @@ def test_trends_aggregation_first_matching_event_for_user(self):
         assert len(response.results) == 1
         assert response.results[0]["count"] == 1
         assert response.results[0]["data"] == [0, 0, 1, 0]
+
+    def test_trends_aggregation_first_matching_event_for_user_with_breakdown(self):
+        _create_person(
+            team=self.team,
+            distinct_ids=["p1"],
+            properties={},
+        )
+        _create_person(
+            team=self.team,
+            distinct_ids=["p2"],
+            properties={},
+        )
+
+        # these events outside date range should be ignored
+        _create_event(
+            team=self.team,
+            event="$pageview",
+            distinct_id="p1",
+            timestamp="2020-01-06T12:00:00Z",
+            properties={"$browser": "Chrome"},
+        )
+        _create_event(
+            team=self.team,
+            event="$pageview",
+            distinct_id="p2",
+            timestamp="2020-01-06T12:00:00Z",
+            properties={"$browser": "Firefox"},
+        )
+        _create_event(
+            team=self.team,
+            event="$pageview",
+            distinct_id="p1",
+            timestamp="2020-01-06T13:00:00Z",
+            properties={"$browser": "Firefox"},
+        )
+
+        # only this event for p1 should be included
+        _create_event(
+            team=self.team,
+            event="$pageview",
+            distinct_id="p1",
+            timestamp="2020-01-08T12:00:00Z",
+            properties={"$browser": "Chrome"},
+        )
+        _create_event(
+            team=self.team,
+            event="$pageview",
+            distinct_id="p1",
+            timestamp="2020-01-09T12:00:00Z",
+            properties={"$browser": "Chrome"},
+        )
+        _create_event(
+            team=self.team,
+            event="$pageview",
+            distinct_id="p1",
+            timestamp="2020-01-10T12:00:00Z",
+            properties={"$browser": "Firefox"},
+        )
+
+        # only this event for p2 should be included
+        _create_event(
+            team=self.team,
+            event="$pageview",
+            distinct_id="p2",
+            timestamp="2020-01-10T12:00:00Z",
+            properties={"$browser": "Firefox"},
+        )
+
+        _create_event(
+            team=self.team,
+            event="$pageview",
+            distinct_id="p1",
+            timestamp="2020-01-11T12:00:00Z",
+            properties={"$browser": "Firefox"},
+        )
+        _create_event(
+            team=self.team,
+            event="$pageview",
+            distinct_id="p2",
+            timestamp="2020-01-11T12:00:00Z",
+            properties={"$browser": "Firefox"},
+        )
+
+        flush_persons_and_events()
+
+        response = self._run_trends_query(
+            "2020-01-08",
+            "2020-01-11",
+            IntervalType.DAY,
+            [
+                EventsNode(
+                    event="$pageview",
+                    math=BaseMathType.FIRST_MATCHING_EVENT_FOR_USER,
+                )
+            ],
+            TrendsFilter(display=ChartDisplayType.ACTIONS_LINE_GRAPH),
+            BreakdownFilter(breakdown_type=BreakdownType.EVENT, breakdown="$browser"),
+        )
+
+        # one for each breakdown value
+        assert len(response.results) == 2
+
+        # chrome
+        assert response.results[0]["breakdown_value"] == "Chrome"
+        assert response.results[0]["count"] == 1
+        # match on 8th (p1) for first day in time range
+        assert response.results[0]["data"] == [1, 0, 0, 0]
+
+        # firefox
+        assert response.results[1]["breakdown_value"] == "Firefox"
+        assert response.results[1]["count"] == 1
+        # match on 10th (p2) for third day in time range
+        assert response.results[1]["data"] == [0, 0, 1, 0]

posthog/hogql_queries/insights/trends/trends_query_builder.py

@@ -296,13 +296,11 @@ def _get_events_subquery(
         # Just complex series aggregation
         elif self._aggregation_operation.requires_query_orchestration() and (
             self._aggregation_operation.is_first_time_ever_math()
-            or self._aggregation_operation.is_first_matching_event()
         ):
             return self._aggregation_operation.get_first_time_math_query_orchestrator(
                 events_where_clause=events_filter,
                 sample_value=self._sample_value(),
                 event_name_filter=self._event_or_action_where_expr(),
-                is_first_matching_event=self._aggregation_operation.is_first_matching_event(),
             ).build()
         elif self._aggregation_operation.requires_query_orchestration():
             return self._aggregation_operation.get_actors_query_orchestrator(

posthog/hogql_queries/insights/utils/aggregations.py

@@ -81,9 +81,10 @@ def _select_expr(self, date_from: ast.Expr, filters: ast.Expr | None = None, is_
         aggregation_filters = date_from if filters is None else ast.And(exprs=[date_from, filters])
         min_timestamp_expr = (
             ast.Call(name="min", args=[ast.Field(chain=["timestamp"])])
-            if not is_first_matching_event or filters is None
-            else ast.Call(name="minIf", args=[ast.Field(chain=["timestamp"]), filters])
+            if not is_first_matching_event
+            else ast.Call(name="minIf", args=[ast.Field(chain=["timestamp"]), aggregation_filters])
         )
+
         return [
             ast.Alias(
                 alias="min_timestamp",