django/tests/from_db_value/tests.py

from django.db import connection
from django.db.models import Max
from django.test import TestCase

from .models import CashModel, Cash


class FromDBValueTest(TestCase):
    def setUp(self):
        CashModel.objects.create(cash='12.50')

    def test_simple_load(self):
        instance = CashModel.objects.get()
        self.assertIsInstance(instance.cash, Cash)

    def test_values(self):
        values_list = CashModel.objects.values_list('cash', flat=True)
        self.assertIsInstance(values_list[0], Cash)

    def test_aggregation(self):
        maximum = CashModel.objects.aggregate(m=Max('cash'))['m']
        self.assertIsInstance(maximum, Cash)

    def test_defer(self):
        instance = CashModel.objects.defer('cash').get()
        self.assertIsInstance(instance.cash, Cash)

    def test_connection(self):
        instance = CashModel.objects.get()
        self.assertEqual(instance.cash.vendor, connection.vendor)