Delete and retry tasks through Django Admin

django_tasks/backends/database/admin.py

@@ -1,11 +1,34 @@
 from typing import List, Optional
 
 from django.contrib import admin
+from django.db.models import QuerySet
 from django.http import HttpRequest
 
+from django_tasks.task import ResultStatus
+
 from .models import DBTaskResult
 
 
+def reenqueue(
+    modeladmin: admin.ModelAdmin,
+    request: HttpRequest,
+    queryset: QuerySet[DBTaskResult],
+) -> None:
+    tasks = queryset.update(status=ResultStatus.NEW)
+    modeladmin.message_user(request, f"Rescheduled {tasks} tasks.", "SUCCESS")
+
+
+def duplicate(
+    modeladmin: admin.ModelAdmin,
+    request: HttpRequest,
+    queryset: QuerySet[DBTaskResult],
+) -> None:
+    tasks = DBTaskResult.objects.bulk_create(
+        old_task.duplicate() for old_task in queryset
+    )
+    modeladmin.message_user(request, f"Rescheduled {tasks} tasks.", "SUCCESS")
+
+
 @admin.register(DBTaskResult)
 class DBTaskResultAdmin(admin.ModelAdmin):
     list_display = (
@@ -20,17 +43,13 @@ class DBTaskResultAdmin(admin.ModelAdmin):
     )
     list_filter = ("status", "priority", "queue_name")
     ordering = ["-enqueued_at"]
+    actions = [reenqueue, duplicate]
 
     def has_add_permission(
         self, request: HttpRequest, obj: Optional[DBTaskResult] = None
     ) -> bool:
         return False
 
-    def has_delete_permission(
-        self, request: HttpRequest, obj: Optional[DBTaskResult] = None
-    ) -> bool:
-        return False
-
     def has_change_permission(
         self, request: HttpRequest, obj: Optional[DBTaskResult] = None
     ) -> bool:

django_tasks/backends/database/models.py

@@ -10,7 +10,7 @@
 from django.utils import timezone
 from django.utils.module_loading import import_string
 from django.utils.translation import gettext_lazy as _
-from typing_extensions import ParamSpec
+from typing_extensions import ParamSpec, Self
 
 from django_tasks.task import (
     DEFAULT_PRIORITY,
@@ -167,6 +167,7 @@ def task_result(self) -> "TaskResult[T]":
 
         object.__setattr__(task_result, "_exception_class", exception_class)
         object.__setattr__(task_result, "_traceback", self.traceback or None)
+        object.__setattr__(task_result, "_return_value", self.return_value)
 
         return task_result
 
@@ -226,3 +227,13 @@ def set_failed(self, exc: BaseException) -> None:
                 "traceback",
             ]
         )
+
+    def duplicate(self) -> Self:
+        return type(self)(
+            args_kwargs=self.args_kwargs,
+            priority=self.priority,
+            task_path=self.task_path,
+            queue_name=self.queue_name,
+            backend_name=self.backend_name,
+            run_after=self.run_after,
+        )

tests/tests/test_database_backend.py

@@ -26,6 +26,7 @@
 
 from django_tasks import ResultStatus, Task, default_task_backend, tasks
 from django_tasks.backends.database import DatabaseBackend
+from django_tasks.backends.database.backend import TaskResult
 from django_tasks.backends.database.management.commands.prune_db_task_results import (
     logger as prune_db_tasks_logger,
 )
@@ -953,6 +954,28 @@ def test_get_locked_with_locked_rows(self) -> None:
         finally:
             new_connection.close()
 
+    def test_duplicate(self) -> None:
+        result_1 = cast(TaskResult, test_tasks.calculate_meaning_of_life.enqueue())
+        db_result_1 = result_1.db_result
+        db_result_2 = result_1.db_result.duplicate()
+        db_result_2.save()
+        result_2 = db_result_2.task_result
+
+        assert db_result_1.pk != db_result_2.pk
+
+        call_command(
+            "db_worker",
+            verbosity=0,
+            batch=True,
+            interval=0,
+            startup_delay=False,
+        )
+
+        result_1.refresh()
+        result_2.refresh()
+
+        assert result_1.return_value == result_2.return_value
+
 
 class ConnectionExclusiveTranscationTestCase(TestCase):
     def setUp(self) -> None: