Fixed #31918 -- Allowed QuerySet.in_bulk() to fetch on a single distinct field.

1 files changed, 18 insertions, 0 deletions

diff --git a/tests/lookup/tests.py b/tests/lookup/tests.py
index 3d8a801933..9094542808 100644
--- a/tests/lookup/tests.py
+++ b/tests/lookup/tests.py
@@ -207,6 +207,24 @@ class LookupTests(TestCase):
         with self.assertRaisesMessage(ValueError, msg):
             Article.objects.in_bulk([self.au1], field_name='author')
 
+    @skipUnlessDBFeature('can_distinct_on_fields')
+    def test_in_bulk_distinct_field(self):
+        self.assertEqual(
+            Article.objects.order_by('headline').distinct('headline').in_bulk(
+                [self.a1.headline, self.a5.headline],
+                field_name='headline',
+            ),
+            {self.a1.headline: self.a1, self.a5.headline: self.a5},
+        )
+
+    @skipUnlessDBFeature('can_distinct_on_fields')
+    def test_in_bulk_multiple_distinct_field(self):
+        msg = "in_bulk()'s field_name must be a unique field but 'pub_date' isn't."
+        with self.assertRaisesMessage(ValueError, msg):
+            Article.objects.order_by('headline', 'pub_date').distinct(
+                'headline', 'pub_date',
+            ).in_bulk(field_name='pub_date')
+
     @isolate_apps('lookup')
     def test_in_bulk_non_unique_meta_constaint(self):
         class Model(models.Model):