Test FilteredRelation usage

Author: jmfederico

polymorphic/tests/test_orm.py

@@ -3,7 +3,7 @@
 
 from django.contrib.contenttypes.models import ContentType
 from django.db import models
-from django.db.models import Case, Count, Q, When
+from django.db.models import Case, Count, FilteredRelation, Q, When
 from django.db.utils import IntegrityError
 from django.test import TransactionTestCase
 
@@ -1064,6 +1064,39 @@ def ComplexAgg(expression):
         ):
             Model2A.objects.aggregate(ComplexAgg("Model2B___field2"))
 
+    def test_polymorphic__filtered_relation(self):
+        """ test annotation using FilteredRelation """
+
+        blog = BlogA.objects.create(name="Ba1", info="i1 joined")
+        blog.blogentry_set.create(text="bla1 joined")
+        blog.blogentry_set.create(text="bla2 joined")
+        blog.blogentry_set.create(text="bla3 joined")
+        blog.blogentry_set.create(text="bla4")
+        blog.blogentry_set.create(text="bla5")
+        BlogA.objects.create(name="Ba2", info="i2 joined")
+        BlogA.objects.create(name="Ba3", info="i3")
+        BlogB.objects.create(name="Bb3")
+
+        result = BlogA.objects.annotate(
+            text_joined=FilteredRelation("blogentry", condition=Q(blogentry__text__contains="joined")),
+        ).aggregate(Count("text_joined"))
+        self.assertEqual(result, {"text_joined__count": 3})
+
+        result = BlogA.objects.annotate(
+            text_joined=FilteredRelation("blogentry", condition=Q(blogentry__text__contains="joined")),
+        ).aggregate(count=Count("text_joined"))
+        self.assertEqual(result, {"count": 3})
+
+        result = BlogBase.objects.annotate(
+            info_joined=FilteredRelation("bloga", condition=Q(BlogA___info__contains="joined")),
+        ).aggregate(Count("info_joined"))
+        self.assertEqual(result, {"info_joined__count": 2})
+
+        result = BlogBase.objects.annotate(
+            info_joined=FilteredRelation("bloga", condition=Q(BlogA___info__contains="joined")),
+        ).aggregate(count=Count("info_joined"))
+        self.assertEqual(result, {"count": 2})
+
     def test_polymorphic__expressions(self):
 
         from django.db.models.functions import Concat