add tests for asserting number of queries

Author: cathteng

src/sentry/workflow_engine/processors/workflow.py

@@ -133,7 +133,11 @@ def evaluate_workflows_action_filters(
         workflow_event_data = event_data
 
         # each DataConditionGroup here has 1 WorkflowDataConditionGroup
-        workflow_data_condition_group = action_condition.workflowdataconditiongroup_set.first()
+        workflow_data_condition_group = (
+            list(action_condition.workflowdataconditiongroup_set.all())[0]
+            if action_condition.workflowdataconditiongroup_set.exists()
+            else None
+        )
 
         # Populate the workflow_env in the event_data for the action_condition evaluation
         if workflow_data_condition_group:
@@ -228,7 +232,6 @@ def process_workflows(event_data: WorkflowEventData) -> set[Workflow]:
             enabled=True,
         )
         .select_related("when_condition_group")
-        .prefetch_related("when_condition_group__conditions")
         .distinct()
     )
 

tests/sentry/workflow_engine/processors/test_workflow.py

@@ -361,9 +361,10 @@ def test_workflow_filtered_out(self):
 
     def test_many_workflows(self):
         workflow_two, _, _, _ = self.create_detector_and_workflow(name_prefix="two")
-        triggered_workflows = evaluate_workflow_triggers(
-            {self.workflow, workflow_two}, self.event_data
-        )
+        workflows = set(Workflow.objects.all().select_related("when_condition_group").distinct())
+        with self.assertNumQueries(2):
+            # 1 query per workflow to fetch data conditions
+            triggered_workflows = evaluate_workflow_triggers(workflows, self.event_data)
 
         assert triggered_workflows == {self.workflow, workflow_two}
 
@@ -535,6 +536,14 @@ def test_basic__no_filter(self):
         triggered_actions = evaluate_workflows_action_filters({self.workflow}, self.event_data)
         assert set(triggered_actions) == {self.action}
 
+    @patch("sentry.workflow_engine.processors.workflow.filter_recently_fired_workflow_actions")
+    def test_basic__num_queries(self, mock_filter):
+        # isolate the number of queries in the outer function
+        with self.assertNumQueries(3):
+            # 2 queries for action conditions (including subquery to prefetch)
+            # 1 query for workflow data conditions
+            evaluate_workflows_action_filters({self.workflow}, self.event_data)
+
     def test_basic__with_filter__passes(self):
         self.create_data_condition(
             condition_group=self.action_group,