kfet -- Create initial statement on checkout save

- Why? Because it should be the actual behavior.
- To allow using arithmetic operations with values of DecimalField when
object are not retrieved from DB, some strings are replaced by Decimal
or int.
If you wonder why it's not automatically done, see:
https://code.djangoproject.com/ticket/27825

kfet/models.py

@@ -362,6 +362,22 @@ class Checkout(models.Model):
     def __str__(self):
         return self.name
 
+    def save(self, *args, **kwargs):
+        created = self.pk is None
+
+        ret = super().save(*args, **kwargs)
+
+        if created:
+            self.statements.create(
+                amount_taken=0,
+                balance_old=self.balance,
+                balance_new=self.balance,
+                by=self.created_by,
+            )
+
+        return ret
+
+
 class CheckoutTransfer(models.Model):
     from_checkout = models.ForeignKey(
         Checkout, on_delete = models.PROTECT,

kfet/tests/test_models.py

@@ -1,7 +1,12 @@
+import datetime
+
 from django.contrib.auth import get_user_model
 from django.test import TestCase
+from django.utils import timezone
 
-from kfet.models import Account
+from kfet.models import Account, Checkout
+
+from .utils import create_user
 
 User = get_user_model()
 
@@ -23,3 +28,33 @@ class AccountTests(TestCase):
 
         with self.assertRaises(Account.DoesNotExist):
             Account.objects.get_by_password('bernard')
+
+
+class CheckoutTests(TestCase):
+
+    def setUp(self):
+        self.now = timezone.now()
+
+        self.u = create_user()
+        self.u_acc = self.u.profile.account_kfet
+
+        self.c = Checkout(
+            created_by=self.u_acc,
+            valid_from=self.now,
+            valid_to=self.now + datetime.timedelta(days=1),
+        )
+
+    def test_initial_statement(self):
+        """A statement is added with initial balance on creation."""
+        self.c.balance = 10
+        self.c.save()
+
+        st = self.c.statements.get()
+        self.assertEqual(st.balance_new, 10)
+        self.assertEqual(st.amount_taken, 0)
+        self.assertEqual(st.amount_error, 0)
+
+        # Saving again doesn't create a new statement.
+        self.c.save()
+
+        self.assertEqual(self.c.statements.count(), 1)

kfet/tests/test_views.py

@@ -746,12 +746,16 @@ class CheckoutReadViewTests(ViewTestCaseMixin, TestCase):
 
     def setUp(self):
         super().setUp()
-        self.checkout = Checkout.objects.create(
-            name='Checkout',
-            created_by=self.accounts['team'],
-            valid_from=self.now,
-            valid_to=self.now + timedelta(days=5),
-        )
+
+        with mock.patch('django.utils.timezone.now') as mock_now:
+            mock_now.return_value = self.now
+
+            self.checkout = Checkout.objects.create(
+                name='Checkout', balance=Decimal('10'),
+                created_by=self.accounts['team'],
+                valid_from=self.now,
+                valid_to=self.now + timedelta(days=1),
+            )
 
     def test_ok(self):
         r = self.client.get(self.url)
@@ -794,7 +798,7 @@ class CheckoutUpdateViewTests(ViewTestCaseMixin, TestCase):
             name='Checkout',
             valid_from=self.now,
             valid_to=self.now + timedelta(days=5),
-            balance='3.14',
+            balance=Decimal('3.14'),
             is_protected=False,
             created_by=self.accounts['team'],
         )
@@ -864,6 +868,7 @@ class CheckoutStatementListViewTests(ViewTestCaseMixin, TestCase):
         self.assertQuerysetEqual(
             r.context['checkoutstatements'],
             map(repr, expected_statements),
+            ordered=False,
         )
 
 

kfet/views.py

@@ -528,15 +528,7 @@ class CheckoutCreate(SuccessMessageMixin, CreateView):
 
         # Creating
         form.instance.created_by = self.request.user.profile.account_kfet
-        checkout = form.save()
-
-        # Création d'un relevé avec balance initiale
-        CheckoutStatement.objects.create(
-                checkout = checkout,
-                by = self.request.user.profile.account_kfet,
-                balance_old = checkout.balance,
-                balance_new = checkout.balance,
-                amount_taken = 0)
+        form.save()
 
         return super(CheckoutCreate, self).form_valid(form)