Correctly order run_after tasks (#154)

With all other things equal, older tasks should come first (meaning they'll more likely to be run closer to their `run_after` date)

Author: RealOrangeOne

django_tasks/backends/database/migrations/0015_alter_dbtaskresult_options.py

@@ -0,0 +1,23 @@
+# Generated by Django 5.1.5 on 2025-04-27 12:00
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("django_tasks_database", "0014_remove_dbtaskresult_exception_data"),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name="dbtaskresult",
+            options={
+                "ordering": [
+                    models.OrderBy(models.F("priority"), descending=True),
+                    models.OrderBy(models.F("run_after"), nulls_last=True),
+                ],
+                "verbose_name": "Task Result",
+                "verbose_name_plural": "Task Results",
+            },
+        ),
+    ]

django_tasks/backends/database/models.py

@@ -108,7 +108,7 @@ class DBTaskResult(GenericBase[P, T], models.Model):
     objects = DBTaskResultQuerySet.as_manager()
 
     class Meta:
-        ordering = [F("priority").desc(), F("run_after").desc(nulls_last=True)]
+        ordering = [F("priority").desc(), F("run_after").asc(nulls_last=True)]
         verbose_name = _("Task Result")
         verbose_name_plural = _("Task Results")
 

tests/tests/test_database_backend.py

@@ -638,6 +638,14 @@ def test_run_after(self) -> None:
         self.assertEqual(DBTaskResult.objects.succeeded().count(), 1)
 
     def test_run_after_priority(self) -> None:
+        old_task = test_tasks.noop_task.using(
+            priority=20, run_after=timezone.now() - timedelta(hours=2)
+        ).enqueue()
+
+        very_old_task = test_tasks.noop_task.using(
+            priority=20, run_after=timezone.now() - timedelta(hours=10)
+        ).enqueue()
+
         far_future_result = test_tasks.noop_task.using(
             run_after=timezone.now() + timedelta(hours=10)
         ).enqueue()
@@ -658,18 +666,22 @@ def test_run_after_priority(self) -> None:
         self.assertEqual(
             [dbt.task_result for dbt in DBTaskResult.objects.all()],
             [
+                very_old_task,
+                old_task,
                 high_priority_far_future_result,
                 high_priority_result,
                 low_priority_result,
-                far_future_result,
                 future_result,
+                far_future_result,
                 lower_priority_result,
             ],
         )
 
         self.assertEqual(
             [dbt.task_result for dbt in DBTaskResult.objects.ready()],
             [
+                very_old_task,
+                old_task,
                 high_priority_result,
                 low_priority_result,
                 lower_priority_result,