Serialize arguments in task, rather than each backend

This avoids duplication, and makes backend implementations simpler

django_tasks/backends/database/backend.py

@@ -13,7 +13,6 @@
 from django_tasks.signals import task_enqueued
 from django_tasks.task import Task
 from django_tasks.task import TaskResult as BaseTaskResult
-from django_tasks.utils import json_normalize
 
 if TYPE_CHECKING:
     from .models import DBTaskResult
@@ -38,7 +37,7 @@ def _task_to_db_task(
         from .models import DBTaskResult
 
         return DBTaskResult(
-            args_kwargs=json_normalize({"args": args, "kwargs": kwargs}),
+            args_kwargs={"args": args, "kwargs": kwargs},
             priority=task.priority,
             task_path=task.module_path,
             queue_name=task.queue_name,

django_tasks/backends/dummy.py

@@ -9,7 +9,7 @@
 from django_tasks.exceptions import ResultDoesNotExist
 from django_tasks.signals import task_enqueued
 from django_tasks.task import ResultStatus, Task, TaskResult
-from django_tasks.utils import get_random_id, json_normalize
+from django_tasks.utils import get_random_id
 
 from .base import BaseTaskBackend
 
@@ -44,8 +44,8 @@ def enqueue(
             enqueued_at=None,
             started_at=None,
             finished_at=None,
-            args=json_normalize(args),
-            kwargs=json_normalize(kwargs),
+            args=args,
+            kwargs=kwargs,
             backend=self.alias,
         )
 

django_tasks/backends/immediate.py

@@ -78,8 +78,8 @@ def enqueue(
             enqueued_at=None,
             started_at=None,
             finished_at=None,
-            args=json_normalize(args),
-            kwargs=json_normalize(kwargs),
+            args=args,
+            kwargs=kwargs,
             backend=self.alias,
         )
 

django_tasks/task.py

@@ -21,7 +21,12 @@
 from typing_extensions import ParamSpec, Self
 
 from .exceptions import ResultDoesNotExist
-from .utils import SerializedExceptionDict, exception_from_dict, get_module_path
+from .utils import (
+    SerializedExceptionDict,
+    exception_from_dict,
+    get_module_path,
+    json_normalize,
+)
 
 if TYPE_CHECKING:
     from .backends.base import BaseTaskBackend
@@ -118,13 +123,17 @@ def enqueue(self, *args: P.args, **kwargs: P.kwargs) -> "TaskResult[T]":
         """
         Queue up the task to be executed
         """
-        return self.get_backend().enqueue(self, args, kwargs)
+        return self.get_backend().enqueue(
+            self, json_normalize(args), json_normalize(kwargs)
+        )
 
     async def aenqueue(self, *args: P.args, **kwargs: P.kwargs) -> "TaskResult[T]":
         """
         Queue up a task function (or coroutine) to be executed
         """
-        return await self.get_backend().aenqueue(self, args, kwargs)
+        return await self.get_backend().aenqueue(
+            self, json_normalize(args), json_normalize(kwargs)
+        )
 
     def get_result(self, result_id: str) -> "TaskResult[T]":
         """

tests/tasks.py

@@ -1,20 +1,21 @@
 import time
+from typing import Any
 
 from django_tasks import task
 
 
 @task()
-def noop_task(*args: tuple, **kwargs: dict) -> None:
+def noop_task(*args: Any, **kwargs: Any) -> None:
     return None
 
 
 @task
-def noop_task_from_bare_decorator(*args: tuple, **kwargs: dict) -> None:
+def noop_task_from_bare_decorator(*args: Any, **kwargs: Any) -> None:
     return None
 
 
 @task()
-async def noop_task_async(*args: tuple, **kwargs: dict) -> None:
+async def noop_task_async(*args: Any, **kwargs: Any) -> None:
     return None
 
 

tests/tests/test_tasks.py

@@ -68,6 +68,18 @@ async def test_enqueue_task_async(self) -> None:
 
         self.assertEqual(default_task_backend.results, [result])  # type:ignore[attr-defined]
 
+    def test_enqueue_with_invalid_argument(self) -> None:
+        with self.assertRaisesMessage(
+            TypeError, "Object of type datetime is not JSON serializable"
+        ):
+            test_tasks.noop_task.enqueue(datetime.now())
+
+    async def test_aenqueue_with_invalid_argument(self) -> None:
+        with self.assertRaisesMessage(
+            TypeError, "Object of type datetime is not JSON serializable"
+        ):
+            await test_tasks.noop_task.aenqueue(datetime.now())
+
     def test_using_priority(self) -> None:
         self.assertEqual(test_tasks.noop_task.priority, 0)
         self.assertEqual(test_tasks.noop_task.using(priority=1).priority, 1)