Refs #31310 -- Added test for check for using intermediate model with ambiguous foreign key from model.

tests/invalid_models_tests/test_relative_fields.py

@@ -128,6 +128,36 @@ class RelativeFieldTests(SimpleTestCase):
             ),
         ])
 
+    def test_ambiguous_relationship_model_from(self):
+        class Person(models.Model):
+            pass
+
+        class Group(models.Model):
+            field = models.ManyToManyField('Person', through='AmbiguousRelationship')
+
+        class AmbiguousRelationship(models.Model):
+            person = models.ForeignKey(Person, models.CASCADE)
+            first_group = models.ForeignKey(Group, models.CASCADE, related_name='first')
+            second_group = models.ForeignKey(Group, models.CASCADE, related_name='second')
+
+        field = Group._meta.get_field('field')
+        self.assertEqual(field.check(from_model=Group), [
+            Error(
+                "The model is used as an intermediate model by "
+                "'invalid_models_tests.Group.field', but it has more than one "
+                "foreign key from 'Group', which is ambiguous. You must "
+                "specify which foreign key Django should use via the "
+                "through_fields keyword argument.",
+                hint=(
+                    'If you want to create a recursive relationship, use '
+                    'ForeignKey("self", symmetrical=False, '
+                    'through="AmbiguousRelationship").'
+                ),
+                obj=field,
+                id='fields.E334',
+            ),
+        ])
+
     def test_ambiguous_relationship_model(self):
 
         class Person(models.Model):