fix(cohorts): Add default property tests

posthog/api/cohort.py

@@ -10,6 +10,7 @@
     get_feature_flag_hash_key_overrides,
 )
 from posthog.models.person.person import PersonDistinctId
+from posthog.models.property.property import Property
 from posthog.queries.insight import insight_sync_execute
 import posthoganalytics
 from posthog.metrics import LABEL_TEAM_ID
@@ -556,7 +557,7 @@ def insert_actors_into_cohort_by_query(cohort: Cohort, query: str, params: Dict[
         capture_exception(err)
 
 
-def get_cohort_actors_for_feature_flag(cohort_id: int, flag: str, team_id: int, batchsize: int = 5_000):
+def get_cohort_actors_for_feature_flag(cohort_id: int, flag: str, team_id: int, batchsize: int = 1_000):
     # :TODO: Find a way to incorporate this into the same code path as feature flag evaluation
     try:
         feature_flag = FeatureFlag.objects.get(team_id=team_id, key=flag)
@@ -572,14 +573,16 @@ def get_cohort_actors_for_feature_flag(cohort_id: int, flag: str, team_id: int,
     cohorts_cache = {}
 
     if feature_flag.uses_cohorts:
+        # TODO: Consider disabling flags with cohorts for creating static cohorts
+        # because this is currently a lot more inefficient for flag matching,
+        # as we're required to go to the database for each person.
         cohorts_cache = {cohort.pk: cohort for cohort in Cohort.objects.filter(team_id=team_id, deleted=False)}
 
     default_person_properties = {}
     for condition in feature_flag.conditions:
         property_list = Filter(data=condition).property_groups.flat
         for property in property_list:
-            if property.operator not in ("is_set", "is_not_set") and property.type == "person":
-                default_person_properties[property.key] = ""
+            default_person_properties.update(get_default_person_property(property, cohorts_cache))
 
     try:
         # QuerySet.Iterator() doesn't work with pgbouncer, it will load everything into memory and then stream
@@ -596,7 +599,7 @@ def get_cohort_actors_for_feature_flag(cohort_id: int, flag: str, team_id: int,
             #     "distinct_id", flat=True
             # )[0]
             distinct_id_subquery = Subquery(
-                PersonDistinctId.objects.filter(person_id=OuterRef("person_id")).values_list("id", flat=True)[:1]
+                PersonDistinctId.objects.filter(person_id=OuterRef("person_id")).values_list("id", flat=True)[:3]
             )
             prefetch_related_objects(
                 batch_of_persons,
@@ -612,6 +615,10 @@ def get_cohort_actors_for_feature_flag(cohort_id: int, flag: str, team_id: int,
                 break
 
             for person in all_persons:
+                # ignore almost-deleted persons / persons with no distinct ids
+                if len(person.distinct_ids) == 0:
+                    continue
+
                 distinct_id = person.distinct_ids[0]
                 person_overrides = {}
                 if feature_flag.ensure_experience_continuity:
@@ -660,3 +667,30 @@ def get_cohort_actors_for_feature_flag(cohort_id: int, flag: str, team_id: int,
         if settings.DEBUG or settings.TEST:
             raise err
         capture_exception(err)
+
+
+def get_default_person_property(prop: Property, cohorts_cache: Dict[int, Cohort]):
+    default_person_properties = {}
+
+    if prop.operator not in ("is_set", "is_not_set") and prop.type == "person":
+        default_person_properties[prop.key] = ""
+    elif prop.type == "cohort" and not isinstance(prop.value, list):
+        try:
+            parsed_cohort_id = int(prop.value)
+        except (ValueError, TypeError):
+            return None
+        cohort = cohorts_cache.get(parsed_cohort_id)
+        if cohort:
+            return get_default_person_properties_for_cohort(cohort, cohorts_cache)
+    return default_person_properties
+
+
+def get_default_person_properties_for_cohort(cohort: Cohort, cohorts_cache: Dict[int, Cohort]) -> Dict[str, str]:
+    """
+    Returns a dictionary of default person properties to use when evaluating a feature flag
+    """
+    default_person_properties = {}
+    for property in cohort.properties.flat:
+        default_person_properties.update(get_default_person_property(property, cohorts_cache))
+
+    return default_person_properties