Fixed #25054 -- Added app_label to swapped model AttributeError

django/db/models/manager.py

@@ -270,9 +270,13 @@ class SwappedManagerDescriptor(object):
         self.model = model
 
     def __get__(self, instance, type=None):
-        raise AttributeError("Manager isn't available; %s has been swapped for '%s'" % (
-            self.model._meta.object_name, self.model._meta.swapped
-        ))
+        raise AttributeError(
+            "Manager isn't available; '%s.%s' has been swapped for '%s'" % (
+                self.model._meta.app_label,
+                self.model._meta.object_name,
+                self.model._meta.swapped,
+            )
+        )
 
 
 class EmptyManager(Manager):

tests/managers_regress/tests.py

@@ -109,12 +109,12 @@ class ManagersRegressionTests(TestCase):
 
             # Accessing the manager on a swappable model should
             # raise an attribute error with a helpful message
-            try:
+            msg = (
+                "Manager isn't available; 'managers_regress.SwappableModel' "
+                "has been swapped for 'managers_regress.Parent'"
+            )
+            with self.assertRaisesMessage(AttributeError, msg):
                 SwappableModel.objects.all()
-                self.fail('Should raise an AttributeError')
-            except AttributeError as e:
-                self.assertEqual(str(e), "Manager isn't available; SwappableModel has been swapped for 'managers_regress.Parent'")
-
         finally:
             apps.app_configs['managers_regress'].models = _old_models
             apps.all_models['managers_regress'] = _old_models
@@ -128,7 +128,6 @@ class ManagersRegressionTests(TestCase):
 
         try:
             class SwappableModel(models.Model):
-
                 stuff = models.Manager()
 
                 class Meta:
@@ -137,12 +136,12 @@ class ManagersRegressionTests(TestCase):
             # Accessing the manager on a swappable model with an
             # explicit manager should raise an attribute error with a
             # helpful message
-            try:
+            msg = (
+                "Manager isn't available; 'managers_regress.SwappableModel' "
+                "has been swapped for 'managers_regress.Parent'"
+            )
+            with self.assertRaisesMessage(AttributeError, msg):
                 SwappableModel.stuff.all()
-                self.fail('Should raise an AttributeError')
-            except AttributeError as e:
-                self.assertEqual(str(e), "Manager isn't available; SwappableModel has been swapped for 'managers_regress.Parent'")
-
         finally:
             apps.app_configs['managers_regress'].models = _old_models
             apps.all_models['managers_regress'] = _old_models
@@ -156,7 +155,6 @@ class ManagersRegressionTests(TestCase):
 
         try:
             class SwappableModel(models.Model):
-
                 objects = models.Manager()
 
                 class Meta:
@@ -165,12 +163,12 @@ class ManagersRegressionTests(TestCase):
             # Accessing the manager on a swappable model with an
             # explicit manager should raise an attribute error with a
             # helpful message
-            try:
+            msg = (
+                "Manager isn't available; 'managers_regress.SwappableModel' "
+                "has been swapped for 'managers_regress.Parent'"
+            )
+            with self.assertRaisesMessage(AttributeError, msg):
                 SwappableModel.objects.all()
-                self.fail('Should raise an AttributeError')
-            except AttributeError as e:
-                self.assertEqual(str(e), "Manager isn't available; SwappableModel has been swapped for 'managers_regress.Parent'")
-
         finally:
             apps.app_configs['managers_regress'].models = _old_models
             apps.all_models['managers_regress'] = _old_models