Ticket #14373: 14373_r13978_initial_tests.diff

tests/regressiontests/aggregation_regress/tests.py

@@ -625 +625 @@
             lambda: Book.objects.annotate(mean_age=Avg('authors__age')).annotate(Avg('mean_age'))
         )
 
+    def test_m2m_overwrite(self):
+        "Regression for #14373: don't let annotate/aggregate lose m2m data."
+        list(Book.objects.all().annotate(authors=Count('authors')))
+        self.assertEqual(sorted(a.name for a in Book.objects.get(pk=1).authors.all()),
+                         ['Adrian Holovaty', 'Jacob Kaplan-Moss'])
+
     if run_stddev_tests():
         def test_stddev(self):
             self.assertEqual(

tests/regressiontests/m2m_regress/models.py

@@ -57 +57 @@
     name = models.CharField(max_length=30)
     friends = models.ManyToManyField(auth.User)
 
+# Regression for #14373 -- Assigning an integer as the value of an m2m related
+# attribute should raise ValueError, not clear all relationships.
+
+class Platform(models.Model):
+    name = models.CharField(max_length=25)
+    tags = models.ManyToManyField(Tag)
+
 __test__ = {"regressions": """
 # Multiple m2m references to the same model or a different model must be
 # distinguished when accessing the relations through an instance attribute.

new file tests/regressiontests/m2m_regress/tests.py

@@ +1 @@
+from django.test import TestCase
+
+from regressiontests.m2m_regress.models import Platform, Tag
+
+class M2MAssignmentTests(TestCase):
+    """
+    Regression tests for #14373. Assigning nonsense to an m2m attribute
+    shouldn't silently lose data.
+
+    """
+    def setUp(self):
+        self.platform = Platform.objects.create(name='BSD')
+        self.platform.tags = [Tag.objects.create(name='Net'),
+                              Tag.objects.create(name='Free')]
+
+    def test_assigning_integer(self):
+        try:
+            self.platform.tags = 7
+        except TypeError:
+            pass
+        else:
+            self.fail("Assignment of integer to m2m attribute should have raised TypeError")
+        self.assertEqual(sorted(t.name for t in self.platform.tags.all()),
+                         ['Free', 'Net'])