Fixed #26348 -- Added TruncTime and exposed it through the __time lookup.

Thanks Tim for the review.

1 files changed, 25 insertions, 1 deletions

diff --git a/tests/db_functions/test_datetime.py b/tests/db_functions/test_datetime.py
index e727ea5b7d..1b44c9a658 100644
--- a/tests/db_functions/test_datetime.py
+++ b/tests/db_functions/test_datetime.py
@@ -9,7 +9,7 @@ from django.db.models import DateField, DateTimeField, IntegerField, TimeField
 from django.db.models.functions import (
     Extract, ExtractDay, ExtractHour, ExtractMinute, ExtractMonth,
     ExtractSecond, ExtractWeekDay, ExtractYear, Trunc, TruncDate, TruncDay,
-    TruncHour, TruncMinute, TruncMonth, TruncSecond, TruncYear,
+    TruncHour, TruncMinute, TruncMonth, TruncSecond, TruncTime, TruncYear,
 )
 from django.test import TestCase, override_settings
 from django.utils import timezone
@@ -512,6 +512,30 @@ class DateFunctionTests(TestCase):
         with self.assertRaisesMessage(ValueError, "Cannot truncate TimeField 'start_time' to DateField"):
             list(DTModel.objects.annotate(truncated=TruncDate('start_time', output_field=TimeField())))
 
+    def test_trunc_time_func(self):
+        start_datetime = microsecond_support(datetime(2015, 6, 15, 14, 30, 50, 321))
+        end_datetime = microsecond_support(datetime(2016, 6, 15, 14, 10, 50, 123))
+        if settings.USE_TZ:
+            start_datetime = timezone.make_aware(start_datetime, is_dst=False)
+            end_datetime = timezone.make_aware(end_datetime, is_dst=False)
+        self.create_model(start_datetime, end_datetime)
+        self.create_model(end_datetime, start_datetime)
+        self.assertQuerysetEqual(
+            DTModel.objects.annotate(extracted=TruncTime('start_datetime')).order_by('start_datetime'),
+            [
+                (start_datetime, start_datetime.time()),
+                (end_datetime, end_datetime.time()),
+            ],
+            lambda m: (m.start_datetime, m.extracted)
+        )
+        self.assertEqual(DTModel.objects.filter(start_datetime__time=TruncTime('start_datetime')).count(), 2)
+
+        with self.assertRaisesMessage(ValueError, "Cannot truncate DateField 'start_date' to TimeField"):
+            list(DTModel.objects.annotate(truncated=TruncTime('start_date')))
+
+        with self.assertRaisesMessage(ValueError, "Cannot truncate DateField 'start_date' to TimeField"):
+            list(DTModel.objects.annotate(truncated=TruncTime('start_date', output_field=DateField())))
+
     def test_trunc_day_func(self):
         start_datetime = microsecond_support(datetime(2015, 6, 15, 14, 30, 50, 321))
         end_datetime = truncate_to(microsecond_support(datetime(2016, 6, 15, 14, 10, 50, 123)), 'day')