Add computation of total without tax amount_before_tax()

coin/billing/models.py

@@ -78,6 +78,13 @@ class Invoice(models.Model):
         return total.quantize(Decimal('0.01'))
     amount.short_description = 'Montant'
 
+    def amount_before_tax(self):
+        total = Decimal('0.0')
+        for detail in self.details.all():
+            total += detail.amount
+        return total.quantize(Decimal('0.01'))
+    amount.short_description = 'Montant HT'
+
     def amount_paid(self):
         """
         Calcul le montant payé de la facture en fonction des éléments

coin/billing/tests.py

@@ -134,6 +134,26 @@ class BillingInvoiceCreationTests(TestCase):
         
         self.assertEqual(invoice.amount(), 111)
 
+    def test_invoice_amount_before_tax(self):
+        invoice = Invoice(member=self.member)
+        invoice.save()
+
+        invoice.details.create(label=self.offer.name,
+                               amount=100,
+                               offersubscription=self.subscription,
+                               period_from=datetime.date(2014, 1, 1),
+                               period_to=datetime.date(2014, 3, 31),
+                               tax=0)
+
+        invoice.details.create(label=self.offer.name,
+                               amount=10,
+                               offersubscription=self.subscription,
+                               period_from=datetime.date(2014, 6, 1),
+                               period_to=datetime.date(2014, 8, 31),
+                               tax=10)
+        
+        self.assertEqual(invoice.amount_before_tax(), 110)
+
     def test_non_billable_offer_isnt_charged(self):
         """
         Test qu'une offre non facturable n'est pas prise en compte