Fixed #26648 -- Added a system check for invalid related_query_name's containing underscores.

1 files changed, 28 insertions, 3 deletions

diff --git a/tests/invalid_models_tests/test_relative_fields.py b/tests/invalid_models_tests/test_relative_fields.py
index 2534b345c2..b681e35587 100644
--- a/tests/invalid_models_tests/test_relative_fields.py
+++ b/tests/invalid_models_tests/test_relative_fields.py
@@ -714,7 +714,7 @@ class RelativeFieldTests(SimpleTestCase):
             pass
 
         for invalid_related_name in invalid_related_names:
-            Child = type(str('Child_%s') % str(invalid_related_name), (models.Model,), {
+            Child = type(str('Child%s') % str(invalid_related_name), (models.Model,), {
                 'parent': models.ForeignKey('Parent', models.CASCADE, related_name=invalid_related_name),
                 '__module__': Parent.__module__,
             })
@@ -723,7 +723,7 @@ class RelativeFieldTests(SimpleTestCase):
             errors = Child.check()
             expected = [
                 Error(
-                    "The name '%s' is invalid related_name for field Child_%s.parent"
+                    "The name '%s' is invalid related_name for field Child%s.parent"
                     % (invalid_related_name, invalid_related_name),
                     hint="Related name must be a valid Python identifier or end with a '+'",
                     obj=field,
@@ -743,7 +743,6 @@ class RelativeFieldTests(SimpleTestCase):
             '_starts_with_underscore',
             'contains_%s_digit' % digit,
             'ends_with_plus+',
-            '_',
             '_+',
             '+',
         ]
@@ -813,6 +812,32 @@ class RelativeFieldTests(SimpleTestCase):
             ),
         ])
 
+    def test_invalid_related_query_name(self):
+        class Target(models.Model):
+            pass
+
+        class Model(models.Model):
+            first = models.ForeignKey(Target, models.CASCADE, related_name='contains__double')
+            second = models.ForeignKey(Target, models.CASCADE, related_query_name='ends_underscore_')
+
+        self.assertEqual(Model.check(), [
+            Error(
+                "Reverse query name 'contains__double' must not contain '__'.",
+                hint=("Add or change a related_name or related_query_name "
+                      "argument for this field."),
+                obj=Model._meta.get_field('first'),
+                id='fields.E309',
+            ),
+            Error(
+                "Reverse query name 'ends_underscore_' must not end with an "
+                "underscore.",
+                hint=("Add or change a related_name or related_query_name "
+                      "argument for this field."),
+                obj=Model._meta.get_field('second'),
+                id='fields.E308',
+            ),
+        ])
+
 
 @isolate_apps('invalid_models_tests')
 class AccessorClashTests(SimpleTestCase):