Set date to validation date

ref #85

coin/billing/models.py

@@ -171,6 +171,7 @@ class Invoice(models.Model):
         Switch invoice to validate mode. This set to False the draft field
         and generate the pdf
         """
+        self.date = datetime.date.today()
         self.number = Invoice.objects.get_next_invoice_number(self.date)
         self.validated = True
         self.save()

coin/billing/tests.py

@@ -242,3 +242,9 @@ class InvoiceQuerySetTests(TestCase):
         self.assertEqual(
             Invoice.objects.get_next_invoice_number(datetime.date(2016,1,1)),
             '2016-01-000002')
+
+    def test_date_is_validation_date(self):
+        bill = Invoice.objects.create(date=datetime.date(2016,1,1))
+        self.assertEqual(bill.date, datetime.date(2016,1,1))
+        bill.validate()
+        self.assertEqual(bill.date, datetime.date.today())