Add tests for database limits of SmallIntegerField

Author: timgraham

tests/model_fields_/models.py

@@ -13,6 +13,11 @@
 from django_mongodb_backend.models import EmbeddedModel
 
 
+class UniqueIntegers(models.Model):
+ small = models.SmallIntegerField(unique=True, blank=True, null=True)
+ positive_small = models.PositiveSmallIntegerField(unique=True, blank=True, null=True)
+
+
 # ObjectIdField
 class ObjectIdModel(models.Model):
  field = ObjectIdField()

tests/model_fields_/test_integerfield.py

@@ -0,0 +1,49 @@
+from django.db import IntegrityError
+from django.test import TestCase
+
+from .models import UniqueIntegers
+
+
+class SmallIntegerFieldTests(TestCase):
+ max_value = 2**31 - 1
+ min_value = -(2**31)
+
+ def test_unique_max_value(self):
+ """
+ SmallIntegerField.db_type() is "int" which means unique constraints
+ are only enforced up to 32-bit values.
+ """
+ UniqueIntegers.objects.create(small=self.max_value + 1)
+ UniqueIntegers.objects.create(small=self.max_value + 1) # no IntegrityError
+ UniqueIntegers.objects.create(small=self.max_value)
+ with self.assertRaises(IntegrityError):
+ UniqueIntegers.objects.create(small=self.max_value)
+
+ def test_unique_min_value(self):
+ """
+ SmallIntegerField.db_type() is "int" which means unique constraints
+ are only enforced down to negative 32-bit values.
+ """
+ UniqueIntegers.objects.create(small=self.min_value - 1)
+ UniqueIntegers.objects.create(small=self.min_value - 1) # no IntegrityError
+ UniqueIntegers.objects.create(small=self.min_value)
+ with self.assertRaises(IntegrityError):
+ UniqueIntegers.objects.create(small=self.min_value)
+
+
+class PositiveSmallIntegerFieldTests(TestCase):
+ max_value = 2**31 - 1
+
+ def test_unique_max_value(self):
+ """
+ SmallIntegerField.db_type() is "int" which means unique constraints
+ are only enforced up to 32-bit values.
+ """
+ UniqueIntegers.objects.create(positive_small=self.max_value + 1)
+ UniqueIntegers.objects.create(positive_small=self.max_value + 1) # no IntegrityError
+ UniqueIntegers.objects.create(positive_small=self.max_value)
+ with self.assertRaises(IntegrityError):
+ UniqueIntegers.objects.create(positive_small=self.max_value)
+
+ # test_unique_min_value isn't needed since PositiveSmallIntegerField has a
+ # limit of zero (enforced only in forms and model validation).