old_contents: from django.test import TestCase, Client
  from django.contrib.auth.models import User
  from billjobs.models import Bill, Service
  from billjobs.settings import BILLJOBS_BILL_ISSUER
  
  class BillingTestCase(TestCase):
      ''' Test billing creation and modification '''
      fixtures = ['dev_data.json']
  
      def setUp(self):
          self.user = User.objects.get(username='bill')
  
      def tearDown(self):
          pass
  
      def test_create_bill_with_one_line(self):
          ''' Test when user is created a bill with a single service '''
          #response = self.client.get('/admin/billjobs/bill/add/', follow_redirect=True)
          #self.assertEqual(response.status_code, 200)
          self.assertTrue(True)
  
      def test_create_bill(self):
          bill = Bill(user=self.user)
          bill.save()
          self.assertEqual(bill.user.username, self.user.username)
          self.assertEqual(bill.issuer_address, BILLJOBS_BILL_ISSUER)
          self.assertEqual(
                  bill.billing_address, self.user.userprofile.billing_address)
  
      def test_user_change_billing_address(self):
          ''' Test when user is changing is billing address
              Previous bill is with old address
              New bill is with new address
          '''
          pass
  
new_contents: from django.test import TestCase, Client
  from django.contrib.auth.models import User
  from billjobs.models import Bill, Service
  from billjobs.settings import BILLJOBS_BILL_ISSUER
  
  class BillingTestCase(TestCase):
      ''' Test billing creation and modification '''
      fixtures = ['dev_data.json']
  
      def setUp(self):
          self.user = User.objects.get(username='bill')
  
      def tearDown(self):
          pass
  
      def test_create_bill_with_one_line(self):
          ''' Test when user is created a bill with a single service '''
          #response = self.client.get('/admin/billjobs/bill/add/', follow_redirect=True)
          #self.assertEqual(response.status_code, 200)
          self.assertTrue(True)
  
      def test_create_bill(self):
          bill = Bill(user=self.user)
          bill.save()
          self.assertEqual(bill.user.username, self.user.username)
          self.assertEqual(bill.issuer_address, BILLJOBS_BILL_ISSUER)
          self.assertEqual(
                  bill.billing_address, self.user.userprofile.billing_address)
  
      def test_user_change_billing_address(self):
          ''' Test when user is changing is billing address
              Previous bill is with old address
              New bill is with new address
          '''
          bill = Bill(user=self.user)
          previous_billing_address = self.user.userprofile.billing_address
          bill.save()
          # user change billing_address
          self.user.userprofile.billing_address = '1 new street\n34000 Town'
          self.user.save()
          new_billing_address = self.user.userprofile.billing_address
          # user create a new bill
          new_bill = Bill(user=self.user)
          new_bill.save()
          self.assertEqual(bill.billing_address, previous_billing_address)
          self.assertEqual(new_bill.billing_address, new_billing_address)
  
subject: Test when user change billing address old bill info does not change and new have the new one