Check transaction support when using ENQUEUE_ON_COMMIT

Author: RealOrangeOne

django_tasks/backends/base.py

@@ -148,4 +148,15 @@ def check(self, **kwargs: Any) -> Iterable[messages.CheckMessage]:
             yield messages.Error(
                 "`ENQUEUE_ON_COMMIT` cannot be used when no databases are configured",
                 hint="Set `ENQUEUE_ON_COMMIT` to False",
+                id="tasks.E001",
+            )
+
+        if (
+            self.enqueue_on_commit
+            and not connections["default"].features.supports_transactions
+        ):
+            yield messages.Error(
+                "ENQUEUE_ON_COMMIT cannot be used on a database which doesn't support transactions",
+                hint="Set `ENQUEUE_ON_COMMIT` to False",
+                id="tasks.E002",
             )

tests/tests/test_dummy_backend.py

@@ -8,6 +8,7 @@
     SimpleTestCase,
     TransactionTestCase,
     override_settings,
+    skipIfDBFeature,
 )
 from django.urls import reverse
 
@@ -191,10 +192,9 @@ def test_check(self) -> None:
     )
     @mock.patch("django_tasks.backends.base.connections", ConnectionHandler({}))
     def test_enqueue_on_commit_with_no_databases(self) -> None:
-        errors = list(default_task_backend.check())
-
-        self.assertEqual(len(errors), 1)
-        self.assertIn("Set `ENQUEUE_ON_COMMIT` to False", errors[0].hint)  # type:ignore[arg-type]
+        self.assertIn(
+            "tasks.E001", {error.id for error in default_task_backend.check()}
+        )
 
     def test_takes_context(self) -> None:
         result = test_tasks.get_task_id.enqueue()
@@ -347,3 +347,17 @@ def test_task_specific_enqueue_on_commit(self) -> None:
         self.assertIsNone(result.enqueued_at)
         result.refresh()
         self.assertIsNotNone(result.enqueued_at)
+
+    @override_settings(
+        TASKS={
+            "default": {
+                "BACKEND": "django_tasks.backends.dummy.DummyBackend",
+                "ENQUEUE_ON_COMMIT": True,
+            }
+        }
+    )
+    @skipIfDBFeature("supports_transactions")
+    def test_enqueue_on_commit_with_no_transactions(self) -> None:
+        self.assertIn(
+            "tasks.E002", {error.id for error in default_task_backend.check()}
+        )