django/tests/field_subclassing/tests.py

from django.db import connection, models
from django.test import SimpleTestCase

from .fields import CustomDescriptorField, CustomTypedField


class TestDbType(SimpleTestCase):

    def test_db_parameters_respects_db_type(self):
        f = CustomTypedField()
        self.assertEqual(f.db_parameters(connection)['type'], 'custom_field')


class DescriptorClassTest(SimpleTestCase):
    def test_descriptor_class(self):
        class CustomDescriptorModel(models.Model):
            name = CustomDescriptorField(max_length=32)

        m = CustomDescriptorModel()
        self.assertFalse(hasattr(m, '_name_get_count'))
        # The field is set to its default in the model constructor.
        self.assertEqual(m._name_set_count, 1)
        m.name = 'foo'
        self.assertFalse(hasattr(m, '_name_get_count'))
        self.assertEqual(m._name_set_count, 2)
        self.assertEqual(m.name, 'foo')
        self.assertEqual(m._name_get_count, 1)
        self.assertEqual(m._name_set_count, 2)
        m.name = 'bar'
        self.assertEqual(m._name_get_count, 1)
        self.assertEqual(m._name_set_count, 3)
        self.assertEqual(m.name, 'bar')
        self.assertEqual(m._name_get_count, 2)
        self.assertEqual(m._name_set_count, 3)